Illustrated Abdominal Surgery: Based on Embryology and Anatomy of the Digestive System 9789811517969, 9811517967

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Illustrated Abdominal Surgery Based on Embryology and Anatomy of the Digestive System Hisashi Shinohara

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Illustrated Abdominal Surgery

Hisashi Shinohara

Illustrated Abdominal Surgery Based on Embryology and Anatomy of the Digestive System

Hisashi Shinohara, M.D., Ph.D Professor Department of Surgery Hyogo College of Medicine Nishinomiya Hyogo Japan

ISBN 978-981-15-1795-2    ISBN 978-981-15-1796-9 (eBook) https://doi.org/10.1007/978-981-15-1796-9 © Springer Nature Singapore Pte Ltd. 2020 This English translation is based on the Japanese original Irastoreiteddo Gekashujyutsu Originally published in Japan in 2011 by Igaku-Shoin Ltd. This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

Foreword

Although a large number of books are categorized as surgical atlases, which are essentially the surgeon’s lifeline, there are surprisingly few atlases available that truly meet the needs of the clinical surgeon. If surgical illustrations are simplified too much, they can become less realistic and not relatable to actual surgery; if the illustrations are too realistic, they can become more like plain intraoperative photographs that don’t clearly show what is important and what is not. In the past, illustrations were often considered supplementary to the explanatory text, but today where images are often more popular than text, it is expected that almost everything will be explained using illustrations. Achieving the right balance to do this is not as simple as it may first appear though. We can understand this immediately if we really think about the process of writing a surgery book. There are few surgeons highly skilled at surgery who can also draw realistic pictures that are good enough to be used in textbooks, and illustrators are usually lay persons with no knowledge of surgery. This means thnat when the illustrator creates illustrations based on the author’s notes and instructions, the information the author intends to convey based on their extensive experience and skills can become lost along the way. Moreover, accomplished surgeons may no longer remember the various challenges they faced early in their surgical career. They have become so used to the steps that they may perform them reflexively, and this can often be problematic enough to confuse trainee or early career surgeons. For these reasons, even though senior surgeons are qualified to teach new techniques to high- or intermediate-­ level surgeons, they may not be able to use illustrations clearly and comprehensively to explain key points to beginners who have just started learning the ropes. So, if one of our colleagues, who may be struggling with questions and problems at a similar level, proposes an experiential solution in their own words, this will be great news and will represent an unprecedented attempt. The author of this book, Dr. Shinohara, is a surgeon perfectly suited for this role. He is a young, extremely talented surgeon who is also a professional-­ level illustrator. Dr. Shinohara started working at our hospital as a resident in his second year after graduating from medical school. Initially, he was one of those highly motivated surgeons who had almost no experience in surgery, but he soon distinguished himself to the extent that he was able to complete almost all kinds of abdominal surgeries on his own, including liver lobectomy and v

Foreword

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pancreaticoduodenectomy, by the end of his 3 years working at our hospital. Of course, what made this possible was not only his gift and talent, but other factors too. For example, during his first gastric surgery, although he must have been nervous performing each step, he kept clear records of the questions he had during the operation and made detailed notes, which were in the form of illustrations not text. As his experience in surgery grew, he continued keeping such notes, and over time they became more detailed and sophisticated with added information and an appropriate mix of emphasis and omission. These illustrations are therefore notes about his practical experience, which he has also enriched with the knowledge and expertise that he has absorbed from senior colleagues along the way. Considering the brilliance of the rough sketches and the fact that they helped his rapid progress in surgery, I suggested to him that he officially edit them as an educational tool for newcomers, or even publish them and ask for feedback from budding surgeons in the community. I was subsequently contacted by the medical publisher Igaku-Shoin, and the publication of these notes was made possible. Open this atlas and you will see illustrations that are readily usable and give a sense of actually being at the surgery. You will also recognize that the book clearly shows, from the same standpoint, the efforts and trials of a young surgeon who was struggling to become an established surgeon. Although some local terms are used for certain surgical procedures and instruments, the underlying philosophies of the anatomy and physiology remain the same wherever we are, as are the basic principles of surgery. This book creatively conveys a message that is fresh and directly originates from actual scenes in surgery. I hope that this book will be carefully read by interested readers and practically applied to actual surgery. February 1994  

Yoshihiko Makino Hyogo Prefectural Amagasaki Hospital Hyogo, Japan

Preface

Anatomy is without question the basis of surgery, but the surgeon’s mindset often tends more toward an understanding of “clinical” or “topographic” anatomy. This is because surgeons can’t perform surgeries simply by memorizing the contents of Sobotta’s Atlas of Human Anatomy or Netter’s Atlas of Human Anatomy although both are undoubtedly excellent books. Just as maps of the world with south-up orientation can look completely different from those with north-up orientation, the human anatomy encountered during surgery is not static and is highly variable—it changes constantly depending on the approach to the operative field and as the surgery progress, and what we see in open surgery is very different from that in endoscopic surgery. Surgeons constantly modify our atlas based on our intraoperative experiences and interpretations, and our interpretations certainly affect the quality of the surgery performed. For this reason, I set out to create a high-quality, detailed atlas of surgical procedures by providing with hand-drawn illustrations of the interpreted and reconstructed anatomy I have seen. This is the English translation of the third edition of my textbook written in Japanese, Illustrated Surgery: Points of Surgical Techniques from the Anatomical Perspective of Membranes (Igaku-Shoin Publishing, Tokyo). The original edition was published in 1994, in my 5th year of residency. It was a unique textbook in which I sought to record operations learned from my first mentor Dr. Yoshihiko Makino as faithfully as possible using illustrations of step-by-step surgical procedures. It was reprinted more than expected, and the second edition was published with minor revisions in 1998. After a 12-year interval, in 2010 I published the 3rd edition with major revisions to reflect my accumulating experiences as a surgeon and to include more detailed topographic anatomical knowledge gained during endoscopic surgery and newly acquired embryologic knowledge that explains the continuity of membranes and dissection layers. In order to do that, simply updating the existing illustrations in the former edition would have been insufficient, so I created anew a total of 687 illustrations for 532 surgical steps. It took three and a half years to finish them all even though I set myself the task of completing one illustration every day. It was quite a job to sit after work (and on weekends) in front of a blank piece of paper with a pencil ready, but it was worth the effort: I’m pleased that the 3rd edition has been well received by

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young surgeons as well as by readers of the previous editions. More than 38,000 copies of the Japanese versions have been sold at this time of writing, a figure that is roughly 1.9 times the number of members of the Japanese Society of Gastroenterological Surgery. The Chinese translation was published in 2013 and the Korean translation in 2014. I am thrilled that Springer Japan recognizes the value of this book and has published this English version to reach more surgeons worldwide. This textbook does not have a conventional structure. For example, illustrations dominate with the text limited to concise accompanying figure legends. Plain language is used as much as possible to help communicate as clearly as possible the dynamic and realistic situations encountered by surgeons. The illustrations included are close to what surgeons actually see during surgery (e.g., with surgical devices and the operators’ hands also depicted) so that readers can move through the procedures as smoothly as if actually doing them. Also, there are no ambiguous lines in any of the illustrations, which I believe is the most important point. All lines have start and end points because lines drawn with intention will help readers understand the anatomy more clearly. I purposely used monochrome illustrations to enhance the information communicated by such lines. Today, with the popularity of endoscopic surgery, we can learn the excellent surgical maneuvers of experienced surgeons easily using clear video images. Yet, no matter how beautiful surgical videos are, they still offer only a small sample of what we surgeons will actually see, and not all of the operating surgeons’ intentions will be communicated. Also, even though the operating surgeons will clearly recognize the dissectible loose connective tissue layers and the small vessels in them, viewers are likely to miss them in the recorded procedures. The most effective way to convey such information is, undoubtedly, through illustrations. Indeed, surgical fields in any dissection plane can be shown freely this way. So, this book presents illustrations of open surgery to better explain the clinical anatomy and also takes an innovative approach by showing many illustrations of cross-sectional views to support the main illustrations. In this way, it is the ideal textbook to help readers understand the focus points and topographic anatomy of the surrounding structures. My sincere hope is that the three-dimensional illustrations in this book inspire young surgeons who are keen to improve their surgical skills and help them simulate surgeries. Finally, I would like to thank Dr. Andrianos Tsekrekos (Karolinska University, Sweden) for encouraging me to publish this English version; Ms. Caryn Jones and Ms. Yuki Hidaka for editing the English text patiently and tirelessly; Ms. Kazuko Morozumi for helping with the labeling of illustrations; and Ms. Yoko Arai and other staff of Springer Japan. This book is dedicated to two very important people: Dr. Yoshihiko Makino—my lifelong

Preface

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mentor—and Prof. Yoshiharu Sasaki (Kyoto University), who have always cared about me and my work and provided continuous encouragement and support.

January 2020

Hisashi Shinohara

Contents

1 Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis Through Understanding of Developmental Process ������������������������������������   1 1.1 Introduction������������������������������������������������������������������������������   1 1.2 Prologue������������������������������������������������������������������������������������   2 1.3 Rotation of the Stomach������������������������������������������������������������   4 1.4 The Beginning of Intestinal Rotation����������������������������������������   6 1.5 Collision of the Pancreas and Duodenum ��������������������������������   8 1.6 Completion of Intestinal Rotation��������������������������������������������  10 1.7 Collision of the Transverse Mesocolon������������������������������������  12 1.8 Collision of the Ascending and Descending Colons����������������  15 1.9 Expansion of the Greater Omentum ����������������������������������������  15 2 Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge��������������������  21 3 Distal Gastrectomy��������������������������������������������������������������������������  33 4 Total Gastrectomy����������������������������������������������������������������������������  91 5 Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer�������������������������������������������������������������������� 133 5.1 Part I: Abdominal Manipulation ���������������������������������������������� 133 5.2 Part II: Thoracic Manipulation�������������������������������������������������� 153 6 Right Hemicolectomy���������������������������������������������������������������������� 187 7 Appendectomy���������������������������������������������������������������������������������� 209 8 Anatomy of the Rectum and Surrounding Structures ���������������� 223 8.1 Pelvis and Ligaments���������������������������������������������������������������� 223 8.2 Iliopsoas, Internal Obturator, and Piriformis Muscles�������������� 224 8.3 Structure of the Pelvic Floor: Part I������������������������������������������ 225 8.4 Structure of the Pelvic Floor: Part II���������������������������������������� 227 8.5 Internal Iliac Artery and Its Branches �������������������������������������� 229 8.6 Internal Pudendal Artery and Its Branches ������������������������������ 229 8.7 Anatomy of the Nervous System (Somatic Nervous System) ������������������������������������������������������ 231 8.8 Anatomy of the Nervous System (Autonomic Nervous System) �������������������������������������������������� 231 xi

Contents

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8.9 Structure of the Retrorectal Space: Part I��������������������������������� 234 8.10 Structure of the Retrorectal Space: Part II�������������������������������� 236 8.11 Structure of the Prerectal Space������������������������������������������������ 239 8.12 End Point of Pre- and Retro-­Rectal Dissection������������������������ 239 8.13 Lateral Ligament���������������������������������������������������������������������� 239 8.14 Three-Dimensional Construction of the Rectum and Nerves�������������������������������������������������������� 242 8.15 Fascia Propria of the Rectum: Part I ���������������������������������������� 244 8.16 Fascia Propria of the Rectum: Part II���������������������������������������� 246 9 Sigmoidectomy �������������������������������������������������������������������������������� 247 10 Low Anterior Resection of the Rectum������������������������������������������ 263 11 Abdominoperineal Resection of the Rectum �������������������������������� 291 12 Surgical Repair of Rectal Prolapse: The Altemeier Procedure���������������������������������������������������������������� 305 13 Hemorrhoidectomy�������������������������������������������������������������������������� 319 14 Right Hemihepatectomy������������������������������������������������������������������ 327 15 Left Lateral Sectionectomy ������������������������������������������������������������ 369 16 Laparoscopic Cholecystectomy������������������������������������������������������ 399 17 Open Cholecystectomy�������������������������������������������������������������������� 419 18 Pancreaticoduodenectomy: Whipple Procedure �������������������������� 435 19 Anatomy of the Inguinal Canal and Surrounding Structures���������� 481 20 Repair of Inguinal Hernia: Mesh Plug������������������������������������������ 495 Bibliography �������������������������������������������������������������������������������������������� 515

1

Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis Through Understanding of Developmental Process

Abstract

This chapter describes the anatomy of the stomach, the pivotal organ in the upper abdomen, and surrounding structures based on the author’s embryological understanding. The intestinal primordium consists of the foregut, midgut, and hindgut. The stomach and proximal duodenum arise from the foregut. The gastrointestinal tract is anchored to the body wall by the mesentery, as are the stomach and duodenum. The stomach has the dorsal mesogastrium, as its main mesentery, and the ventral mesogastrium, which are both supplied by the celiac artery. Following rotation of the stomach and rotation of the midgut, the two major events during fetal life, these two mesenteries are significantly deformed, distended, anchored, and fused with adjacent mesenteries. The pancreas arises from the duodenal wall and extends through the mesoduodenum into the dorsal mesogastrium. The pancreas is therefore embedded in the mesentery. The principal concept behind gastric cancer surgery is to resect the mesogastrium while sparing the pancreas. A full understanding of the contour of the mesogastrium is therefore important to performing a reasonable operation. Keywords

Stomach · Mesentery · Mesogastrium Anatomy · Embryology

1.1

Introduction

In surgery for gastrointestinal malignancy, it is generally recommended to remove the tumor-­ bearing organ together with its mesentery [1]. This would not be very difficult if the stomach and intestine were a straight tube. But in reality, two events occurring in the embryonic stage—rotation of the stomach and rotation of the intestine—result in the formation of a complex three-dimensional (3D) structure of the mesentery. This major movement of the stomach and intestine causes torsion of the mesentery, which was originally a simple plane, and subsequent linked events of collision and fusion. This elaborately programmed, significant, in utero event is a true spectacle show that opens with bulging of the dorsal mesentery of the stomach and closes with formation of the extensive greater omentum as the grand finale. To properly dissect this complex mesentery at its base, surgeons seek to release fusions and restore the pre-collision structure of the mesentery. Therefore, understanding the anatomy of the stomach, the core organ of the major movement, and surrounding structures significantly influences the quality of not only curative surgery for gastric cancer but also other surgeries such as pancreaticoduodenectomy and curative surgery for colon cancer. In this chapter, we try to clearly reproduce this spectacle show on paper, while also detailing the blood vessels and membranes commonly handled by surgeons during surgery.

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_1

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1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis…

Why does the omental bursa end in the middle of the transverse mesocolon? Why is the greater omentum made of multiple layers of membranes? Why is the main pancreatic duct curved sharply at the head of the pancreas? Why does the inferior pancreaticoduodenal artery, the first branch of the superior mesenteric artery, often form a common duct with the first jejunal artery at its root? Readers who have such questions are strongly encouraged to read this chapter. After viewing the spectacle show, it should be easier to understand and accept certain degrees of variation, such as the right hepatic artery originating from the superior mesenteric artery.

1.2

Prologue

The show begins around the fifth fetal week when one intestinal primordium is connected to the abdominal wall via the mesentery (Fig. 1.1). The superficial peritoneum is a monolayered squamous epithelium composed of mesothelial cells, and so is a genuine “membrane.” Mesothelial cells show no clear cell boundaries when stained with standard procedures but show clear boundaries between polygonal cells when treated with silver nitrate. Outside the peritoneum is the extraperitoneal fat, spaced by a small gap containing loose connective tissue. When viewed from the body surface side, the fat tissue is located anterior to the peritoneum and is therefore referred to as preperitoneal fat during surgery for inguinal hernia. The inner and outer surfaces of extraperitoneal fat are covered by a thin connective tissue membrane referred to as the subperitoneal fascia. The inner (peritoneal side) fascia is specifically referred to as the subretroperitoneal fascia, again a name based on the observation from the peritoneal side. Now we are using the term “fascia.” The fascia is essentially a dense connective tissue that has no epithelial cell arrangement as observed in the peritoneum, meaning that it is not a true “membrane.” Therefore, the question of how many fascias are present between A and B often makes no sense. The fascia present out-

side the extraperitoneal fat makes contact with the fascia transversalis, the main player in the inguinal anatomy, again spaced by a small gap containing loose connective tissue. Outside the fascia transversalis are abdominal muscles. The layers between the peritoneum and the fascia transversalis are collectively referred to as the retroperitoneal space, which is again referred to as the preperitoneal space during surgery for inguinal hernia. In any case, although we might find it a little uncomfortable to refer to the layer of fat or loose connective tissue as a space, the term “space” is used instead of “cavity” to indicate an artificially expanded space. A number of such spaces are present in the abdomen, including the retrorectal space as detailed in Chap. 8. The kidney is embedded in the retroperitoneal space, as shown in the lower left corner of Fig.  1.1. The kidney is initially located in the pelvis and gradually ascends within the layer of extraperitoneal fat. The mesentery is a fat fold that anchors the intestine to the abdominal wall and has a double-­ layered structure in which the peritoneum and the subperitoneal fascia surround its surface in an omega shape. The peritoneum and the subperitoneal fascia are spaced by a small gap containing loose connective tissue and can be separated into two layers. Fat corresponds to the “intermediate layer” of the mesentery and serves as a conduit for blood vessels, lymphatics, and nerves to reach the intestine. In this book, this fat layer is often referred to as “flesh.” In the schematic diagrams (cross-sectional view) that frequently appear in this book, aside from a few exceptions, the peritoneum is shown as a thick line, the fascia as a thin line, and the gap between the two layers, consisting of loose connective tissue, as an equally spaced, ladder-like short thin lines connecting the two layers. The intermediate layer is lightly shaded. The intestinal primordium consists of the foregut (giving rise to the stomach, proximal duodenum, hepatobiliary system, and pancreas), the midgut (the distal duodenum to proximal transverse colon), and the hindgut (the distal trans-

1.2 Prologue

3 Mesentery Peritoneum

Dorsal mesogastrium Intermediate layer

Aorta

Subperitoneal fascia (internal side) Esophagus

Extraperitoneal fat Subperitoneal fascia (external side) Fascia transversalis

Ductus venosus (Arantius’ duct) Ventral mesogastrium Dorsal pancreas

LGA

Abdominal wall muscles

CA

SPA

Proper hepatic a. CHA

TP UP

GDA Retroperitoneal space

IPDA SMA

Common bile duct Gallbladder Ventral pancreas

*

IMA

Ligamentum teres

R kidney

Vitelline duct

Fig. 1.1  Primitive gastrointestinal tract and the various derivatives in the fifth week of development

verse colon to rectum) [2, 3]. They are anchored to the posterior wall via dorsal mesentery. The dorsal pancreas arises from the duodenum [4], grows in the dorsal mesoduodenum, and eventually extends into the dorsal mesogastrium. The cell mass within the dorsal mesogastrium gives rise to the spleen. The dorsal mesogastrium is slightly c­ oncave on the left side (Fig.  1.1). The foregut is also anchored to the anterior wall via its ventral mesentery (ventral mesogastrium and ventral mesoduodenum), which gives rise to the liver (not shown in the figures before Sect. 1.6).

The common bile duct arises from the liver, gives rise to the gallbladder, and then forms a common orifice (major duodenal papilla, indicated by asterisk symbol in Fig.  1.1) with the ventral pancreas, which also arose within the ventral mesoduodenum, as a communication path to the intestinal tract. These facts support the premise that all abdominal organs, including the hepatobiliary system, pancreas, and spleen, have their own mesentery. The digestive tract, hepatobiliary system, pancreas, and spleen are vascularized by three

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1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis…

arteries that arise from the aorta and pass through the mesentery: (1) the celiac artery (CA); (2) the superior mesenteric artery (SMA); and (3) the inferior mesenteric artery (IMA). These three arteries supply organs arising from the foregut, midgut, and hindgut, respectively. The CA, the most divergently supplying artery of the three, is forced to immediately divide into three branches: the left gastric artery (LGA), splenic artery (SPA), and common hepatic artery (CHA). The subsequent rotation of the stomach causes these arteries to run a crooked course. Moreover, the gastroduodenal artery (GDA) and the inferior pancreaticoduodenal artery (IPDA) usually form a clear anastomosis referred to as the pancreaticoduodenal arcade between the celiac and superior mesenteric artery systems. The IPDA is the first branch of the SMA. Blood oxygenated in the placenta returns to the fetus through the umbilical vein. The umbilical vein passes through the liver while distributing blood to the hepatic sinusoids and leads to the main portal vein. Thereafter, it becomes the ductus venosus (Arantius’ duct) draining into the inferior vena cava. The hepatic sinusoids become the transverse portion of the portal vein (TP) after birth. The umbilical vein, after serving its purpose, becomes obliterated and is replaced by a cord; however, the portion connected to the hepatic sinusoids remains as the umbilical por-

tion of the portal vein (UP). This cord is referred to as the ligamentum teres. The ductus venosus is also obliterated and is itself replaced by a cord (ligamentum venosum) that connects the UP and the inferior vena cava. The ligamentum venosum is attached by the ventral mesentery of the stomach (lesser omentum). The direction of blood flow in the TP is reversed after birth (Fig. 1.2).

1.3

Rotation of the Stomach

Around the sixth week of gestation, the dorsal mesogastrium begins to inflate toward the left, like a sail swelled out by the wind (small arrow in Fig. 1.3). This also causes a major shift of the dorsal pancreas and spleen, which are within the mesentery, to the left. This causes a clockwise rotation of the stomach along the longitudinal axis, resulting in the dorsal and ventral margins becoming the greater and lesser curvatures and the right and left walls becoming the posterior and anterior walls, respectively. The swollen mesentery forms a sac-like structure called the omental bursa and later becomes the greater omentum [5]. The ventral mesogastrium attached to the liver also moves to the right in a clockwise direction, which facilitates stomach rotation (large arrow in Fig.  1.3). This mesentery becomes the lesser omentum.

Ligamentum venosum

Ductus venosus

IVC

TP

TP

UP

Umbilical v.

Before birth

Ligamentum teres

After birth

Fig. 1.2  Changes in the direction of hepatic blood flow before and after the birth

1.3 Rotation of the Stomach

5

Ductus venosus (Arantius’ duct)

Spleen

Ventral mesogastrium

LGA Greater curvature

TP

Dorsal pancreas

UP PHA

RGEA

Dorsal mesogastrium (Omental bursa) Pancreaticoduodenal arcade

Ventral pancreas SMA

SMV

Gerota’s fascia Zuckerkandl’s fascia

RGEA: R gastroepiploic a.

Fig. 1.3  Embryo during the sixth week of development

Figure 1.4 shows a schematic diagram of the dorsal mesogastrium, which is like a sail widely swelled out to the left by the wind, and the ventral mesogastrium, which is pushed to the right by the expanding dorsal mesogastrium. The right margin of the ventral mesogastrium surrounds the vessel group communicating to the liver, consisting of the portal vein, proper hepatic artery, and common bile duct. This structure is referred to as the hepatoduodenal ligament. The kidney ascends while excluding extraperitoneal fat within the retroperitoneal space. This movement of the kidney while pushing the subretroperitoneal fascia from behind causes the

subretroperitoneal fascia to migrate behind the kidney, like seaweed wrapping around a sushi roll. This subretroperitoneal fascia surrounds the kidney with fat and is given a local name, the renal fascia, whose anterior and posterior aspects are referred to as the anterior and posterior layers of the renal fascia, respectively. The definition of the well-known Gerota’s fascia is ambiguous, where some definitions include the perirenal fat. For clinical purposes, the anterior layer of the renal fascia can be regarded as Gerota’s fascia. For reference, the posterior layer of the renal fascia is often referred to as Zuckerkandl’s fascia.

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1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis… Dorsal mesogastrium Aorta Spleen

Ventral mesogastrium

PV

Omental bursa

PHA

Stomach

Common bile duct

Dorsal pancreas

Hepatoduodenal lig.

SMV

SMA

Fig. 1.4  Schematic diagram of the mesogastrium after rotation of the stomach

1.4

 he Beginning of Intestinal T Rotation

The impact of stomach rotation is also evident in the duodenal loop as it begins to bulge to the right during growth. The head of the dorsal pancreas, which is connected to the duodenum, also extends to the right, protruding out of the dorsal mesogastrium (see Fig. 1.5). Meanwhile, the ventral pancreas hides behind the duodenum

along with the common bile duct. This right shifting of the duodenum triggers the rotation of the intestine, the final major event in the midgut in fetal life. This is a major counterclockwise, three-quarter (270-degree) rotation around the SMA, which extends straight to the vitelline duct, as the rotation axis. The initial 90-degree rotation causes the shift of the proximal limb of the midgut loop to the right and the distal limb to the left (Fig. 1.6).

1.4 The Beginning of Intestinal Rotation

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LGA LGEA Dorsal mesogastrium

Ventral mesogastrium

Omental bursa

CHA

Body

RGA

Ventral pancreas

Dorsal pancreas

RGEA

GDA

Head

SMV

SMA

IPDA

Distal limb

Proximal limb

RGA: R gastric a. LGEA: L gastroepiploic a.

Fig. 1.5  The intestinal loops after 90-degree counterclockwise rotation of the midgut

The upcoming major movement of the intestine causes the transformation of the mesentery from a simple plane to a spiral structure. Although many embryology textbooks illustrate this movement of the intestine only, this morphological change in the mesentery is actually more important for surgeons. Of the vessels forming the skel-

eton of the mesentery, three arteries (CA, SMA, and IMA) arise separately from the aorta, while three veins (SPV, SMV, and IMV) converge into the portal vein that drains into the liver. Therefore, an understanding of the torsion of the entire mesentery is helped by thinking that it occurs around the portal vein.

8

1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis…

Omental bursa

Dorsal pancreas SMA SMV Distal limb

Proximal limb

Fig. 1.6  Schematic diagram of the mesogastrium after the initial 90-degree rotation of the midgut

1.5

Collision of the Pancreas and Duodenum

The ventral pancreas migrating behind the duodenum fuses with the dorsal pancreas to form the uncinate process (Fig.  1.7). During this process, the portal vein and the common bile duct are located between the ventral and dorsal pancreas. The ventral pancreatic duct orifice is located slightly inferior to the dorsal pancreatic duct orifice. Once the ventral pancreatic duct becomes the main pancreatic duct after pancreatic fusion, a bridge is formed between the two ducts. This is just like a flood control effort to bring the pancreatic juice produced in the dorsal pancreas into the newly formed main pancreatic duct. This officially turns the ventral pancreatic

duct orifice, which was originally shared with the common bile duct, into the major duodenal papilla (ampulla of Vater). At the same time, the downstream portion of the dorsal pancreatic duct is demoted to the accessory pancreatic duct and its orifice to the minor duodenal papilla. Given this complicated developmental process, it is no wonder that various types of abnormal arrangements of the pancreaticobiliary duct can occur. The pancreas and duodenum then collide with the posterior wall and subsequently anchored to the posterior abdominal wall by fusion of the overlying peritoneal membranes (see Fig.  1.8). It should be noted that fusion occurs only at the level of the peritoneum and the subperitoneal fascia; the lower layers remain intact. The middle part of the pancreas collides with the SMA at around its root but does not undergo peritoneal fusion as it is located at the base of the mesentery. The middle part of the pancreas is firmly anchored to the aorta, from an early stage of development, via well-developed connective tissue that surrounds the SMA and contains nerve plexuses. The fused peritoneum formed by collision is the fusion fascia of Treitz on the pancreatic head/duodenal side (to the right of the midline) and the fusion fascia of Toldt on the pancreatic tail side (to the left of the midline). The term “fascia” can now be used because the peritoneum has become connective tissue due to lysis of epithelial cells caused by collision. The fused peritoneum has lost the glossy appearance it used to have before fusion. Repositioning organs to their original pre-­ collision positions during surgery is referred to as mobilization or displacement. Mobilization of the duodenum is specifically referred to as the Kocher maneuver, which is an important technique used not only for pancreatoduodenectomy but also for periaortic lymphadenectomy during gastric cancer surgery. With this technique, layer separation should be achieved by entering into the gap between the peritoneum and the visceral fascia (black arrow in Fig. 1.8) while keeping the fusion fascia of Treitz attached to the abdominal wall. Mobilization of the pancreatic tail is

1.5 Collision of the Pancreas and Duodenum

9

Dorsal mesogastrium

Common bile duct Acc. pancreatic duct

Treitz lig.

RGEV

Minor duodenal papilla Main pancreatic duct

IPDA MCV

SM

A

ARCV

J1a

* SM

A

Major duodenal papilla

90-degree difference in branching direction

Cecal diverticulum

Uncinate process of pancreas

RGEV: R gastric v. MCV: Middle colic v. ARCV: Accessory r. colic v.

Fig. 1.7  The intestinal loops after 180-degree rotation of the midgut

used for lymphadenectomy around the splenic artery during gastric cancer surgery. Taking into account the continuity with the later-described layer separation procedure for the transverse mesocolon, it is again appropriate to enter into the gap between the subperitoneal fascia on the visceral (pancreatic) side and the fusion fascia of Toldt (white arrow in Fig. 1.8). The subperitoneal fascia in the body/tail part of the pancreas is spe-

cifically referred to as the retropancreatic fascia. The location of a single layer of this fascia on the dorsal aspect of the pancreas after displacement indicates the correctness of the surgical procedure. Another 90 degrees of rotation is applied to the midgut. This is driven by a string that pulls up the duodenojejunal junction (asterisk in Fig.  1.7) toward the diaphragm, a cord

10

1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis… Zuckerkandl’s fascia

Toldt fusion fascia

Gerota’s fascia

Treitz fusion fascia

Mobilization of the pancreatic tail IVC

Ao PV Retropancreatic fascia

IPDA

A SM V SM

Mobilization of duodenum

Omental bursa

Fig. 1.8  Transverse cross section showing collision of the pancreas and duodenum

that later becomes the ligament of Treitz. During the rotation of the midgut, the mesentery is twisted at the root of the SMA, more precisely, between the two branches of the SMA, the IPDA, and the first jejunal artery (J1a) (indicated by the thin dotted line). Perhaps for this reason, the two arteries often form a common duct at their root. In this case, the IPDA arises from the back or left side of the SMA (see Fig.  1.9). This course variation should be kept in mind when dissecting the pancreatic uncinate process during pancreatoduodenectomy. The proximal part of the midgut loop in relation to the vitelline duct grows vigorously and gives rise to a major part of the small intestine. In the meantime, the cecal diverticulum is formed in the distal part of the midgut and subsequently gives rise to the distal end of the ileum up to the right transverse colon. Thereafter, the vitelline

duct regresses and disappears or might remain as Meckel’s diverticulum.

1.6

Completion of Intestinal Rotation

By the tenth week of pregnancy, the midgut loop rotates another 90 degrees to complete the major rotation of 270 degrees in total (Fig. 1.9). The ligament of Treitz, which has pulled the duodenojejunal junction, is now located to the left of the SMA.  The three major branches of the SMA— the IPDA, J1a, and middle colic artery, which were initially on the same plane—are forced to take a 3D branching pattern after mesenteric torsion. This local anatomy should also be kept in mind when performing pancreatoduodenectomy. Tracing along the SMA distally ends up reaching the branch that supplies the terminal ileum (not

1.6  Completion of Intestinal Rotation

11

MCA MCV

Treitz lig.

RGEV IPDA

J1a

Duodenojejunal junction

ARCV

RCA

ICA

MCA; Middle colic a. RCA: R colic a. ICA: Ileocolic a.

Fig. 1.9  The intestinal loops after completing 270-degree rotation of the midgut

the ileocolic artery, which is considered the terminal branch). The branch ends in the part of the ileum where the vitelline duct used to be. Figure 1.10 shows a sagittal cross section along the portal vein through to the superior mesenteric vein (SMV). Here, the gastrocolic

trunk of Henle, which is formed by the convergence of the right gastroepiploic vein (RGEV) and the accessory right colic vein (ARCV), drains into the SMV (indicated by two arrows) corresponding to the “center of torsion” of the mesentery.

1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis…

12

RGA

PV

ta Omen

IVC

l burs

Confluence of L renal v.

Duodenal bulb

Transverse colon

a

Confluence of splenic v.

ARCV

RGEV Gastrocolic trunk of Henle

SM

V

Mesentery of ileum

Treitz fusion fascia J1v Horizontal part of duodenum

Ileum Descending colon

Fig. 1.10  Sagittal cross section along the portal vein through to the superior mesenteric vein

1.7

Collision of the Transverse Mesocolon

The liver, which we have not mentioned so far, now joins the show. The colon, which has completed the planned rotation and is in almost the final position, is going to be fixed sequentially. First, the transverse mesocolon is inverted cranially, causing a major part of the left half of the mesentery to collide with the dorsal mesogastrium, which now appears inflated like a balloon (Fig.  1.11). After the apposed peritoneal membranes are fused with each other, as always, the wide area of the dorsal mesogastrium in contact with the left transverse mesocolon will be recognized as the anterior layer of the mesentery (while the “former” transverse mesocolon becomes the posterior layer). The right margin of the contact surface corresponds to the right border of the omental bursa. The “new” left transverse mesocolon, generated as described above, has a layer structure consisting of, from top to bottom, the peritoneum, subperitoneal fascia, fat, subperitoneal fascia, fusion fascia, subperi-

toneal fascia, fat, subperitoneal fascia, and peritoneum (italics indicate the mesogastrium-derived anterior layer, also circled in Fig. 1.11). It is really astonishing that a membrane of just a few millimeters in thickness, even in adults, contains these many layers. Figure 1.12a shows a sagittal cross section of the omental bursa slightly to the left of the midline. For the separation of the anterior layer of the left transverse mesocolon during gastric cancer surgery (although now rarely performed), it is appropriate to enter into the gap between the peritoneum and the subperitoneal fascia on the omental bursa side while keeping the fused peritoneum on the mesentery side intact (black arrow in Fig. 1.12a). While advancing within this layer, we pass behind the retropancreatic fascia and eventually reach the layer of the displaced pancreatic tail (white arrow in Fig.  1.12a). If wishing to dissect only the peritoneum over the anterior aspect of the pancreas without displacing the pancreatic tail, we will need to penetrate the subperitoneal tissue anteriorly at the lower edge

1.7 Collision of the Transverse Mesocolon

13

Dorsal mesogastrium Omental bursa

RGA SPDA RGEA RGEV Henle

L transverse mesocolon

MC

A

ARCV

MCV

Post. layer of transverse mesocolon

SMA SPDA: Superior pancreatoduodenal a.

Fig. 1.11  Collision of the transverse mesocolon with the mesogastrium

of the pancreas to deliberately transfer to the next upper layer (black thin arrow in Fig. 1.12a). Otherwise, we will continue to migrate under the pancreas, which we do not want to do. It should be noted that the gap between the retroperitoneum and the descending colon (asterisk in Fig. 1.12a) disappears after collision of the ascending and descending colons, as described later.

The right transverse mesocolon, which has not come into contact with the omental bursa, directly collides with the horizontal part of the duodenum and the anterior aspect of the uncinate process of the pancreas, again resulting in fusion of the apposed peritoneal membranes (Fig.  1.12b). At this point, the head/duodenal part of the pancreas has lost its peritoneum

14

1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis…

a LGA SPA

Dorsal mesogastrium

e Om

Fig. 1.12 Sagittal cross section of the omental bursa (a) and the duodenum (b) after collision of the transverse mesocolon

sa ur

lb

nta

Bursectomy

*

b

Descending part of duodenum

Major duodenal papilla

RGEA

1.9 Expansion of the Greater Omentum

over up to three-­quarters of its circumference as a result of fusion, as well as its collision with the retroperitoneum. It should be noted that the gap between the retroperitoneum and the mesostenium (asterisk in Fig.  1.12b) will also disappear in time and become the root of mesostenium (see Fig. 1.16).

1.8

Collision of the Ascending and Descending Colons

Subsequently, the ascending and descending colons are attracted to and collide with the abdominal wall, causing fusion between the ­visceral peritoneum over the mesocolon and the retroperitoneum and subsequent fixation of the colon (Fig.  1.13). The fused peritoneum is also referred to as the fusion fascia of Toldt, as in the case of the pancreatic tail. After collision, the mesentery will remain adherent to the retroperitoneum, although their boundary (Monk’s white line) can be clearly seen due to the slightly different nature of the two peritoneal membranes. As was the case with the preceding collision events, the layer structure of the intermediate fat layer containing blood vessels and lymphoid tissue and the overlaying subperitoneal fascia remains unchanged. Figure 1.14a shows a computed tomography cross section of the ascending and descending colons at the middle part and around the root of the IMA.  When mobilizing the colon, the layer below the fusion fascia of Toldt should be dissected up to the base of the mesentery to ensure that the intermediate layer containing lymph nodes is on the resection side. However, we can still dissect the layer above the fusion fascia of Toldt as long as we do not penetrate the fascia up to the intermediate layer, which is even safer in terms of avoiding damage to the ureter. It should also be remembered that the medial approach, where vascular root ligation is performed first, facilitates dissection below the fusion fascia of Toldt, whereas the lateral approach, where mobilization from Monk’s white line is performed first, facilitates dissection above the fusion fascia of Toldt.

15

Further details will be given in Chap. 6 on right hemicolectomy. Now the anatomy of the stomach and surrounding structures is almost completed, except for the growth of the greater omentum. Let’s go back to Fig.  1.13. First, the dorsal mesogastrium extends downward past the transverse colon while maintaining its sac-like structure (which is cut off in the figure for better view of the cross section). The dorsal mesogastrium also extends to the right and left (arrows in Fig. 1.13), although these parts have no sac-like structure but instead a single-layered structure where only the superficial layer (consisting of, from top to bottom, the peritoneum, subperitoneal fascia, fat, subperitoneal fascia, and peritoneum) is extended. These extended parts of the dorsal mesogastrium is referred to as the greater omentum, which hangs down in the abdominal cavity while widely covering the small intestine. Figure  1.14b illustrates how the greater omentum extends to the right.

1.9

Expansion of the Greater Omentum

After expanding downward while maintaining its sac-like structure, the omental bursa begins to take on a folded double-layered structure formed by fusion of the internal peritoneal membranes. Therefore, this part of the greater omentum (circled in Fig. 1.15) has a layer structure consisting of, from top to bottom, the peritoneum, subperitoneal fascia, fat, subperitoneal fascia, fusion fascia, subperitoneal fascia, fat, subperitoneal fascia, and peritoneum. The part of the greater omentum extending to the right expands over the right transverse mesocolon past the right colic flexure up to the diaphragm, where it stops expanding. The part of the greater omentum that came into contact with the diaphragm becomes the right phrenicocolic ligament, which pulls up the right colic flexure. As the omental bursa extends, the apposed peritoneal membranes are fused with each other, as always. An exception is that three peritoneal membranes fail to merge where they meet (asterisk in

16

1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis…

Dorsal mesogastrium

RGA SPDA

RGEA

RGEV MCV ARCV

Omental bursa

SMA

Post. layer of transverse mesocolon

Fig. 1.13  Extension of the dorsal mesogastrium to form the omental bursa, and collision of the ascending and descending colons

1.9 Expansion of the Greater Omentum

17

a

Jejunum

SMA

IMA

SMV

Monk’s white line

IVC

L colic a.

Ao

Toldt fusion fascia Gerota’s fascia Zuckerkandl‘s fascia

Monk’s white line

Ureter Gonadal a. & v.

b

Infrapyloric v. RGEV

ASPDV

Omental bursa

ARCV SMV

Gr

ea

ter

om

en

tum

Fig. 1.14  Computed tomography cross section of the ascending and descending colons at the middle part (a), and schematic diagram of the extending greater omentum (b)

Fig. 1.16), forming a gap containing loose connective tissue. The right invasion of the greater omentum results in loss of the peritoneum covering the anterior aspect of the pancreatic head, making the whole pancreas a retroperitoneal organ. Thereafter, the greater omentum over the right transverse mesocolon will be recognized as

the anterior layer of the mesentery (as the dorsal mesogastrium is in contact with the left transverse mesocolon), while the “former” transverse mesocolon becomes the posterior layer. Thus, the “new” right transverse mesocolon has exactly the same layer structure as that of the left counterpart, consisting of, from top to bottom, the peri-

18

1  Anatomy of the Stomach and Surrounding Structures, Part I: For Those Who Seek Theoretical Basis…

Ant. layer of L transverse mesocolon

L phrenicocolic lig.

Splenocolic lig. L colic flexure Omental bursa

Ant. layer of L transverse mesocolon

R phrenicocolic lig.

R colic flexure

Greater omentum

Post. layer of transverse mesocolon

Fig. 1.15  Fully developed abdomen after extension of the greater omentum

toneum, subperitoneal fascia, fat, subperitoneal fascia, fusion fascia, subperitoneal fascia, fat, subperitoneal fascia, and peritoneum (italics indicate the omentum-derived anterior layer). This is

well illustrated in the cross section of Fig. 3.12. When looking at the entire transverse colon, the area ratio of the right to left mesocolon is 1:3 to 1:4, with the right border of the omental bursa, or

1.9 Expansion of the Greater Omentum

19 Greater omentum covering anterior aspect of the pancreatic head

PV

Ant. layer of R transverse mesocolon

*

SM

V

Post. layer of transverse mesocolon

IVC Greater omentum

Root of mesentery of small intestine

Fig. 1.16  Sagittal cross section showing the greater omentum extending over the right transverse mesocolon and pancreas

the boundary between both mesocolons, coursing almost along the middle colic artery/vein. Compared with the sagittal cross section in Sect. 1.6, we see that the part of the greater omentum extending to the right is now part of the “new” transverse mesocolon. We can also see that the mesostenium near the center of torsion has fused with the retroperitoneum anterior to the inferior vena cava to form the root of the mesostenium.

The part of the greater omentum extending to the left continues to extend from the lower pole of the spleen toward the left colic flexure and again reaches the diaphragm, where it stops extending. The part of this greater omentum that came into contact with the diaphragm becomes the splenocolic ligament and the left ­phrenicocolic ligament, which pull up the left colic flexure.

2

Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

Abstract

Precise understanding of clinical anatomy comes from precise understanding of embryology. Senior colleagues who make such statements probably have never opened embryology textbooks such as Moore’s “The Developing Human: Clinically Oriented Embryology” or Langman’s “Medical Embryology” but are very good surgeons. A knowledge of embryology is indeed needed, and in this chapter we not only consider embryology but also focus on a slightly different approach to gaining practical knowledge to inform our surgeries. The master carpenter, when building a palace, requires an accurate drawing. But creating a plastic model—a precise miniature of this palace—requires only standard preshaped parts straight out of the box; parts just need to be assembled sequentially from top to bottom, which can be done by anyone with glue. In sur-

gery, if we have a basic understanding of the complex three-dimensional structure of the stomach and surrounding structures (adnexa)— akin to knowing the standard parts needed to assemble a model—we can omit certain theoretically important steps or include them later when needed. In this chapter, we explore the anatomy of the stomach and adnexa, where individual parts are assembled sequentially from deep to superficial. We emphasize only structures that are recognizable as membranes in practice, omitting those strictly defined embryologically such as the retropancreatic fascia and the fusion fascia in the retrocolic spaces. This chapter therefore suits to those who want to learn practical aspects of surgery. Keywords

Stomach · Mesentery · Fascia · Clinical anatomy · Embryology

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_2

21

22

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge Abdominal aorta Esophagus Inf. vena cava Diaphragm (bare area) L gastric a. R adrenal gland

Common hepatic a. Portal v. Gastroduodenal a.

Crus of diaphragm Celiac a. L adrenal gland Splenic a. Splenic v. Sup. mesenteric a.

R gastroepiploic a. R renal v. Sup. mesenteric v.

L renal v. Inf. mesenteric v. Mid. colic a.

Mid. colic v.

Fig. 2.1  Here we see the deepest layer of the abdomen. The shaded area represents the part that has not yet been covered by peritoneum. Blood vessels, the kidney, and the ascending and descending colon are already in place. The underside of the diaphragm that is attached to the bare area

of the liver has no peritoneum, so the muscle fibers are exposed. The left and right crura of the diaphragm surrounding the esophageal hiatus cross and attach to the lumbar spine to form the aortic hiatus. The arrow indicates the route along which the duodenum passes in the next step

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge Fig. 2.2  We can now assemble the pancreas, intrapancreatic bile duct, and duodenum. The horizontal and the lower parts of the duodenum, indicated by the arrow in Fig. 2.1, pass underneath the superior mesenteric artery and vein and enter the abdominal cavity through the ligament of Treitz. The superior pancreaticoduodenal artery (formerly the gastroduodenal artery after branching off from the right gastroepiploic artery) is attached to the portion indicated by the small arrow. The inferior pancreaticoduodenal artery is omitted here

Bile duct

Sup. pancreaticoduodenal a.

Lig . of Treitz

23

24

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

3 2

Post. layer of transverse mesocolon

1

Mid. colic a. & v.

Post. wall of omental bursa

Omental tenia

L gastric a.

b

Foramen of Winslow

a

c

L border of omental bursa

3 Gastropancreatic lig.

2

1

R border of omental bursa

Fig. 2.3  The next two parts for assembly are the posterior layer of the transverse mesocolon (plus the transverse colon), shown in the top left, and the posterior wall of the omental bursa, shown in the top right. The posterior wall of the omental bursa is a single peritoneal membrane consisting of the anterior layer of the left transverse mesocolon ( 1 ), the capsule of the anterior aspect of the pancreatic body and tail ( 2 ), and the retroperitoneum located cranially ( 3 ). The border of the omental bursa is folded back to clearly visualize the sac-like structure of the omental bursa. The right folding line (right border) of the omental bursa runs almost along the middle colic artery and vein, and its

Ant. layer of L transverse mesocolon

left border is at the splenic hilum. The membrane indicated by 3 continues as the retroperitoneum at the right margin of the inferior vena cava to form the posterior wall of the foramen of Winslow (white arrow indicates the route of entry into the omental bursa through this foramen). There is a notch-shaped defect in the retroperitoneum in the area from the abdominal esophagus to the root of the left gastric artery and vein, and this exposes the crus of the diaphragm in front of the aorta. The muscular layer of the stomach directly attaches to this area via loose connective tissue, forming what is called the gastropancreatic fold. The left gastric artery arises from the apex of the notch

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

a

b

25

c

3

2

2

Pancreas

1

Kidney

Post. layer of transverse mesocolon

Fig. 2.3 (continued) The transverse colon is covered by peritoneum, as an extension from the posterior leaf of the mesocolon, along two-thirds of the circumference (between the mesocolic tenia and the omental tenia) on the right side of the right border of the omental bursa; on the left side where the omental bursa is present, it is almost circumferentially covered by the posterior leaf as well as the anterior leaf of the mesocolon (the posterior layer of the omental bursa), which

has been folded back. The bulbous and descending parts of the duodenum and the anterior aspect of the pancreatic head are not yet covered by peritoneum. Here, the three vessels constituting the hepatoduodenal ligament are depicted as a single vessel for convenience. The bottom panels a, b, and c are cross sections along the lines a, b, and c, respectively, shown in the middle panel

26

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

Liver

4 3 2 R gastric a.

Ant. lid of omental bursa

Windows 1

Umbilical portion of portal v. Duct of Arantius

L gastric a.

4 3 Foramen of Winslow R gastriepipioic a.

2 Omental bursa

1

Fig. 2.4  Now we can assemble the liver (excluding the lateral segment) and the anterior lid of the omental bursa. The anterior lid of the omental bursa is a single peritoneal membrane consisting of ① the posterior layer of the gastrocolic ligament, ② the posterior layer of the gastrosplenic ligament, ③ the serosa of the posterior gastric wall, and ④ the posterior layer of the lesser omentum. When we apply an adhesive to the folded area of the posterior wall of the omental bursa, which was assembled in the previous step, and we fit this part inside, we get a sac-like omental bursa. The posterior layer of the lesser omentum (④) attaches to the duct of Arantius, which courses along the boundary

between the medial segment of the liver and Spiegel’s part of the caudate lobe. The right border of the posterior layer continues as the peritoneum behind the hepatoduodenal ligament and serves as the anterior wall of the foramen of Winslow. The top panel of Fig. 2.4 shows two windows that are cut out to visualize the route of entry into the omental bursa from the foramen of Winslow (shown by the white arrow in the lower panel). Here, a part of the S4 segment of the liver is also omitted to provide a clear view of the hepatic portal region. The caudate lobe and gallbladder are omitted. The lower panels (a, b, and c) show cross sections

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

a

4

b

27

c 2

3 Omental bursa Omental bursa

1

Fig. 2.4 (continued)

LGA SPA RGA LGEA

RGEA

LGA

SPA 4 LGEA RGA

RGEA 1

Fig. 2.5  We can then assemble the stomach and spleen, and the roots of the left gastric artery (LGA), right gastric artery (RGA), right gastroepiploic artery (RGEA), and splenic artery (SPA) are adherent. The left gastroepiploic

artery (LGEA) branches from the splenic artery. The spleen is already covered by the serosa, except for the hilum, and is placed in the pocket lateral to the left kidney. The lower panels (a, b, and c) show cross sections

28

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

a

b

c

STM STM Omental bursa

Fig. 2.5 (continued)

Omental bursa

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

5

29

4

6

3

4

Window

1

2

Duct of Arantius

4 3

4

1

Omental bursal

1 2

Post. layer Gastrocolic lig.

Ant. layer of R transverse mesocolon R border of omental bursa

Fig. 2.6 Here the parts of the outermost layer are attached. These parts constitute a single peritoneal membrane that comprises ➊ the anterior leaf of the right transverse mesocolon, ➋ the anterior layer of the gastrocolic ligament, ➌ the anterior layer of the gastrosplenic ligament, ➍ the serosa of the anterior wall of the stomach and duodenum, ➎ the anterior leaf of the lesser omentum, and

Ant. layer

➏ the peritoneum on the anterior aspect of the hepatoduodenal ligament. A large window is cut out at the center of the membrane. The lower panels (a, b, and c) show cross sections. Attaching these parts to the omental tenia gives us circumferential coverage of the transverse colon with peritoneum

30

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

a

b

c

5 4

3

4 Omental bursa 1

Fig. 2.6 (continued)

Omental bursa 1

2

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

1

Greater omentum

Fig. 2.7  By pinching the anterior leaf of the right transverse mesocolon (➊) and the anterior and posterior layers of the gastrocolic ligament (➋ + ①) around their attachment to the transverse colon and then lifting them up to stretch them, we create the greater omentum. The right and left halves of the stretched part have a layered structure composed of two and four layers of peritoneum, respectively. In the right transverse mesocolon, where there is no omental bursa, the greater omentum also ends

21

31

Omental bursa

up serving as the anterior leaf of the transverse mesocolon. The lower panels (a and b) show cross sections As the final step in building our plastic model of the upper abdomen, we attach the lateral segment of the liver (a part of S3 is omitted) Although what we have covered here may not be truly academic because it doesn’t take into account the developmental process, it does offer beginners in stomach surgery a basic but important understanding of the anatomy

32

2  Anatomy of the Stomach and Surrounding Structures, Part II: For Those Who Value Practical Knowledge

a

1

b

Greater omentum

Greater omentum 2

Omental bursa 1

Stretched part Stretched part

Fig. 2.7 (continued)

3

Distal Gastrectomy

Abstract

In this chapter, we work through the procedure for distal gastrectomy with D1+ lymphadenectomy [5] in a step-by-step manner, with written explanations accompanied by clear, simple illustrations. We also look at two reconstruction techniques, the Roux-en-Y technique involving instrumental anastomosis and the classic Billroth-I technique involving manual suturing. Standard operation time is 2 h 30 min. Keywords

Distal gastrectomy · D1+ lymphadenectomy · Billroth-I reconstruction · Roux-en-Y reconstruction Fig. 3.1  Step 1. The operating surgeon stands on the right side of the patient and makes an upper abdominal midline incision extending from the xiphoid process to the umbilicus. The incision may be extended up to the side of the umbilicus depending on the distance between the xiphoid process and the umbilicus. If necessary, the incision is extended toward the left side of the umbilicus. The peritoneum is incised to the left of the round ligament of the liver to open the abdomen

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_3

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34 Fig. 3.2  Step 2. After placing a wound retractor, the abdominal cavity is explored including the liver, the pouch of Douglas, and other structures. The lateral segment of the liver is retracted cranially using an Octopus retractor

Lateral segment

Gallbladder

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35

Stomach

Greater omentum

Omental bursa

Transverse colon

Teniae coli

Fig. 3.3  Opening the omental bursa: Using electrocautery, the attachment of the greater omentum to the transverse colon is incised around the midpoint of the greater curvature of the stomach. The attachment line appears to consist of a single membrane, but actually two layers of

peritoneum have to be penetrated before gaining access to the omental bursa (see Fig. 3.4). In patients with a narrow bursa, it might be difficult to gain access unless the procedure is started more laterally from the left side

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36

“Folded double-layered structure” formed by fusion of two inner peritonea in contact B

A

*

Stomach

Omental bursa

Transverse colon

L gastric a. Celiac axis

Pancreas Dorsal mesogastrium fused with left transverse mesocolon

Common hepatic a.

Ligament of Treitz

Sup. mesenteric a.

Fig. 3.4  What is the origin of this “double peritoneum”? The omental bursa is a bulge of the dorsal mesogastrium that has a “bag-like” shape, with its bottom surface collided and fused with the left transverse mesocolon and the remaining free portion, which has a “folded double-layered structure” formed by fusion of two inner peritonea in contact, hanging down like an apron. So, to gain access to the omental bursa, we have to incise either between the stomach and the folded double-layered structure (A in the figure) or between the folded double-layered structure and the margin of its attachment to the transverse colon (omental tenia) (B in the figure). The latter is more suitable because the layer is thinner and less densely vascularized.

Thus, the “double peritoneum” originates from two peritonea surrounding two sides of the mesogastrium, which is essentially the mesentery of the stomach. These peritonea should not be transected both at once. The superficial layer should be incised first, close to the omental tenia, with a gentle, sliding motion of electrocautery. The incision line should be about 1 cm away from the omental tenia—specifically, right above the border with the serosa of the colon (asterisk in the figure), which corresponds to Monk’s white line in the ascending and descending colon. Care must be taken during this procedure to avoid injury to some of the straight arteries entering the colon, which is pulled up, because they may form a loop under the serosa

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Larger blood vessels in intermediate layer Communicating branch to colon vessels

Blood vessels entering omentum from greater curvature (Epiploic a.)

R gastroepiploic a.

A

Blood vessels entering colon from mesocolon Mid. colic a.

Fig. 3.5  With appropriate tension applied to the dissection line, the serosa of the colon will fall off together with the blood vessels entering the colon and forming a loop. Also, the tip of the electrocautery may be used as a spatula to push the blood vessels toward the colon. The dissection can usually be completed with just the electrocautery because the blood vessels entering the colon from the mesocolon and the vessels entering the greater omentum from the greater curvature are in separate layers, and the blood vessels contained in the intermediate layer of the greater omentum have already narrowed in this area. However, when there are larger blood vessels present in the intermediate layer or any communicating branches to

the colon vessels are encountered, they should be picked up with forceps and cauterized immediately. So, by extending the incision through the deep peritoneal layer as well as through the intermediate fat tissue, we can gain access to the omental bursa. The incision is then continued toward the left colic flexure To open the omental bursa while preserving the greater omentum, it is advisable to enter between the stomach and the folded double-layered structure instead (white arrow). However, care should be taken to keep a distance of 3–4 cm from the arterial arcade to ensure removal of the No. 4 lymph nodes. Also, a number of omental arteries and veins crossing over the dissection line should be ligated while proceeding

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38 Fig. 3.6 After identifying the lower pole of the spleen, the greater omentum is divided toward the arteriovenous anastomosis of the left and right gastroepiploic arteries and veins (gastric arcade). With the greater omentum well stretched out, the omental dissection is continued by dissecting an avascular area with electrocautery while ligating and dividing larger vessels (omental arteries and veins)

Fig. 3.7  The left gastroepiploic artery and vein are ligated and divided. It is not necessary to identify these vessels up to their root in surgery because the lymph nodes around the root of the left gastroepiploic artery are classified as No. 10 station (see Fig. 3.10)

1st gastric branch Epiploic a. & v.

No.4sb LNs

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Short gastric a.

No.4sb LNs

L gastroepiploic a. (ligated)

Fig. 3.8  Several branches of the left gastroepiploic artery are dissected along the gastric wall, returning to the planned transection line of the stomach. When the stomFig. 3.9  A schematic diagram is shown in the left omental dissection, as described in Figs. 3.6, 3.7, and 3.8. After completing the omental dissection on the greater curvature side, the transverse colon is placed back in the abdominal cavity

ach needs to be divided at a higher level, one or two short gastric arteries should be ligated and divided

Tr an

se

ct

io

n

lin

e

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R gastroepiploic a.

4d

L gastroepiploic a. (root) 4sb

10 Stomach posterior wall L gastric a.

co

lon

Transverse mesocolon

sv Tr

an

Pancreas

er

se

Caudate lobe

Splenic a. Incision line of greater omentum

Fig. 3.10  When the greater omentum is to be preserved during laparoscopic surgery, to gain access to the omental bursa, the omental incision should be kept at a distance of several centimeters from the right gastroepiploic artery arcade. Unlike in open surgery, we can take advantage of viewing the operative field from the inside so as to deploy the stomach and the transverse mesocolon in a V shape,

which provides a clear view of the left edge (left border) of the bursa and the splenic hilum. Usually, the splenic artery separates into several branches beyond the pancreatic tail, and the left gastroepiploic artery arises from the lowest branch of the splenic artery, so an omental incision can be made along the route shown for removal of the No. 4sb lymph nodes

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Peritoneum of anterior surface of pancreas

Right border of omental bursa

Fig. 3.11  The omental dissection proceeds by advancing from the midpoint toward the right until identifying the right border of the omental bursa, which corresponds to the folding line at which the anterior layer of the right transverse mesocolon is folded back and continues as the greater omentum. This is incised using Metzenbaum scis-

sors or electrocautery. This border line roughly follows the course of the middle colic artery. The dissection continues upward in that direction, incising the peritoneum that covers the anterior surface of the pancreas until reaching its upper border

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42 Epiploic a. & v.

R gastroepiploic v.

Omental bursa

Accessory right colic. v. Fusion fascia formed by fusion of greater omentum and transverse mesocolon

Incision in right border of omental bursa shown in Fig. 11 Mid. colic v.

Fig. 3.12  Here we see the procedure shown in Fig. 3.11 illustrated in the cross section including the omental bursa. The white arrow indicates how to access the bursa from the foramen of Winslow. There is no omental bursa over the right transverse mesocolon; instead, the mesocolon is covered by and fused with the greater omentum that extends to the right. The omentum includes the right gastroepiploic vein, the transverse mesocolon includes the right accessory colic vein, and both veins merge to form

the gastrocolic trunk of Henle that drains into the superior mesenteric vein (SMV). From now, the procedure for detaching the greater omentum from the right transverse mesocolon starts for removal of the No. 6 subpyloric lymph nodes located along the right gastroepiploic vein. In this step, the correct plane of dissection (black arrow) is the layer just above the fusion fascia that is formed by fusion of the greater omentum and the transverse mesocolon (above is the omentum side)

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R gastroepiploic v.

Gastroduodenal a.

Incision in right border of omental bursa R colic flexure Mid. colic a. & v.

Vasa recta

Fig. 3.13  Heading from the right border of the omental bursa toward the right colic flexure, the edge of the omental attachment onto the transverse colon is divided using electrocautery. In this step, the second assistant pulls the transverse colon caudally with both hands, while the first assistant pulls the omentum cranially, applying moderate tension to the incision line. When incising only the superficial peritoneal layer with electrocautery, loose cotton-­

like connective tissue emerges in the layer underneath, and the cut end of the peritoneum slides over it and shifts to the omentum side. In the same way as in the dissection of the left omentum, the border of the serosa of the colon is identified and the incision is placed right above it. Loop-shaped blood vessels that are occasionally encountered should be spared and returned to the colon side

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44 Proper hepatic a. Portal v.

No.12 LN

No.8 LN

Hepatoduodenal lig.

Greater omentum

Foramen of Winslow

Duodenal bulb

Confluence of splenic v.

SMV No.6 LN R gastroepiploic v.

∗

Gastrocolic trunk of Henle No.14v

Horizontal part of duodenum

IVC

Accessory right colic v. Entry of J1v Excised omentum

Fusion fascia *

Preserved omentum

Access route when preserving omentum

Fig. 3.14  Here we see the plane of dissection shown in step 13 of Fig. 3.13 illustrated in the sagittal cross section, with the greater omentum already detached from the transverse mesocolon. The right gastroepiploic vein from the greater omentum and the right accessory colic vein derived from the transverse mesocolon merge into the gastrocolic trunk of Henle that drains into the SMV. As shown in Fig. 3.14a, after dividing the attachment of the

greater omentum to the transverse colon, the layer above the fusion fascia (asterisk) is entered from below to detach the omentum from the fusion fascia When the greater omentum is to be preserved, the right border of the omental bursa is incised, and from there, the layer indicated by an asterisk in Fig. 3.14a is entered from the left side to transect the greater omentum, followed by detachment of the omentum from the fusion fascia (Fig. 3.14b)

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45 Incision line of omentum

Posterior wall of antrum

Gastroduodenal a.

Mid. colic a. & v.

Incision line of omentum

Accessory right colic v.

Fig. 3.15  To detach the greater omentum from the transverse mesocolon, the two assistants have to apply appropriate countertraction to the dissection line by grasping at three points, two on the transverse colon and one on the omentum (arrows). The surgeon grasps the edge of the incised peritoneum with forceps and peels off the mesocolon as if opening a sealed envelope. The white cotton-like

tissue between the two layers is retracted (as if it were melted) with just light contact with the electrocautery. The layer above the fusion fascia can be entered naturally with a driving force of around 70% traction and 30% electrocautery. The positioning of the countertraction shifts as the dissection progresses, aiming for the gastrocolic trunk of Henle

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R gastroepiploic a.

Gastroduodenal a. Excised greater omentum Top of posterior layer of transverse mesocolon

Mid. colic a. & v. Incision line of right omentum

R of ight bu bo rs rd a e

r

X

Posterior layer of right transverse mesocolon

Incision line of omentum

Preserved greater omentum

Fig. 3.16 Although countertraction is of paramount importance, it is difficult to achieve adequate traction of the transverse colon in laparoscopic surgery. Detachment of the greater omentum is shown after incising the right border of the omental bursa. Ordinarily, the base of the transverse mesocolon is located at a surprisingly high level, around the middle of the pancreatic head (see also Figs. 3.14 and 3.18), so care must be taken to determine

the correct dissection plane of the greater omentum (white arrow), keeping in mind that the posterior leaf of the transverse mesocolon underneath the fusion fascia, which must be preserved, is also lifted more than assumed. Also, care must be taken to avoid easy perforation of the posterior leaf because it is much thinner than the greater omentum—we must advance carefully as indicated by the black arrow

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R gastroepiploic v. ASPDV Right border of omentum

Mid. colic a. & v.

Accessory right colic v.

Right lateral mesocolon (layer of fusion fascia)

Fig. 3.17  After completing the desired fan-shaped dissection, which is required to reach the gastrocolic trunk of Henle, the right border of the greater omentum is incised toward the front of the pancreas. On the detached surface of the transverse mesocolon, the accessory right colic vein

can be seen through the fusion fascia. The right gastroepiploic vein and the anterior superior pancreaticoduodenal vein (ASPDV) can also be seen in the fat tissue over the surface of the pancreas

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48

Supply area of infrapyloric a. & v.

*

CA Infrapyloric a.

SPA CHA GDA RGEA

Infrapyloric v. RGEV Direct branches from pancreatic parenchyma ASPDV Henle

ARCV

Attachment of transverse mesocolon

Fig. 3.18  Vascular anatomy of the infrapyloric area [6] Arterial system: The gastroduodenal artery (GDA) appears on the front of the pancreas after passing between the duodenal bulb and the upper edge of the pancreatic head, and after giving the right gastroepiploic artery (RGEA), it becomes the anterior superior pancreaticoduodenal artery (ASPDA) and dives in the pancreatic parenchyma. This makes it seem like the right gastroepiploic artery arises directly from the pancreatic surface. The infrapyloric artery originates near the root of the ASPDA and branches in a form that resembles an antler, supplying a wide area from the duodenal bulb to the pylorus (shaded area). Because of this, the first gastric branch of the right

gastroepiploic artery enters the stomach quite far from the pyloric ring. The infrapyloric artery may also diverge from the gastroduodenal artery Venous system: As the right gastroepiploic vein (RGEV) descends over the anterior surface of the pancreas, it receives the confluence of the infrapyloric vein and the anterior superior pancreaticoduodenal vein (ASPDV). However, there are usually two or three anterior superior pancreaticoduodenal veins, and the infrapyloric vein can be regarded as the uppermost branch. The infrapyloric vein merges with the accessory right colic vein (ARCV) to form the gastrocolic trunk of Henle that drains into the SMV

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R gastroepiploic a.

Infrapyloric v.

R gastroepiploic v. ASPDV Fusion fascia Location of Henle

Contour of pancreas R gastroepiploic a. & v.

Fig. 3.19  Dissection of the No. 6 lymph nodes [7]: As shown in Fig. 3.14a, the No. 6 lymph nodes are in the fat layer underneath the fusion fascia formed by fusion of the peritoneum over the omentum and of the anterior surface of the pancreas, and this fat layer is essentially the mesentery containing the No. 6 nodes that drain the stomach. Before starting the dissection, the fusion fascia is incised at the lower limit of the No. 6 nodes, that is, at the level of the convergence of the ASPDV, and an incision is made into the fat tissue. This exposes the right gastroepiploic vein, which has been seen transparently. Then, by activating the electrocautery or using it as a spatula, the fat tissue around the

right gastroepiploic vein that contains the lymph nodes is peeled off the surface of the pancreatic parenchyma. Attention should be paid not to damage any thin venous branches draining directly from the pancreatic parenchyma into the left wall of the vein. It should be kept in mind that with the elevation of the pylorus, the head of the pancreas is lifted by the gastroepiploic artery and vein and the parenchyma is raised in a convex shape (Fig. 3.19b) [8]. Because the right gastroepiploic vein can easily be torn after removing the surrounding fat tissue, the second assistant holds the transverse colon while adjusting the traction force so as to apply appropriate tension to the operative field

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Fusion fascia between omentum and pancreas

R gastroepiploic v.

Anterior fascia of pancreas

Infrapyloric v.

6 6

6

6

Incised fusion fascia

ASPDV

No.14v

Fusion fascia between omentum and transverse mesocolon

Fig. 3.20  The dissection of the infrapyloric area is illustrated in the sagittal cross section. To dissect the mesentery containing the No. 6 lymph nodes, it is necessary to transit to another layer, one level deeper than the layer entered, to detach the greater omentum. More specifically, the greater omentum and the transverse mesocolon are detached from the pancreas to broadly expose the fusion fascia on the anterior surface of the pancreas. As shown in Fig. 3.14, there is a gap formed by failed fusion of fascias at the base of the transverse mesocolon. This gap should be entered in order to proceed with the dissection adequately up to the vicinity of the convergence of the ASPDV (so that the mesocolon can be peeled downward) Because in many cases the right gastroepiploic vein can be seen through the fusion fascia at this point, the approximate course of the vein should be determined.

Then, a transverse incision is made on the fusion fascia with activated electrocautery. Once the fusion fascia is penetrated, the fat tissue rupturing the subperitoneal fascia (prepancreatic fascia) is exposed. After incising this fascia, a vertical incision is made into the fat tissue until the anterior surface of the pancreas is reached and the right gastroepiploic vein is exposed. At this point, the incision is redirected horizontally to detach the fat tissue from the pancreatic parenchyma along with the lymph nodes included. In practice, especially during laparotomy, these fascial incisions are performed almost unconsciously without problem. If you carefully examine the fat tissue on the anterior surface of the pancreas before dissecting it, you can see that its surface is covered by a slightly shiny connective tissue. This is the prepancreatic fascia

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51 Excised fusion fascia

Infrapyloric v. Direct branch from pancreatic parenchyma 1st branch of ASPDV

Fig. 3.21  The right gastroepiploic vein is isolated with right angle dissection forceps, ligated with 3-0 Vicryl, and divided. The forceps are passed at the level between the infrapyloric vein and the first branch of the ASPDV; however, they can be passed above the root of the infrapyloric vein if deemed easier. As mentioned earlier, the infrapyloric vein is the last branch of the ASPDV and there is no reason for concern when dividing it at its confluence. Priority should be given to safe handling of the right gastroepiploic vein. Even though the front of the vein is

clearly exposed, bleeding may occur when passing through the forceps. If bleeding occurs, then there has been injury either to the infrapyloric vein as it enters the posterior aspect of the gastroepiploic vein or to a direct branch from the pancreatic parenchyma. Also, in patients whose right gastroepiploic vein runs in a groove formed by protrusion of the parenchyma of the anterior surface of the pancreas, we should not try to thrust the forceps because the tip may penetrate the parenchyma

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Infrapyloric mesentery

4d Distal branch of infrapyloric a. & v.

4d 6 6

R gastroepiploic v. (cut)

6 6

R gastroepiploic a. (root) 6

Dissected No.6 LN

R gastroepiploic v. (root)

Fig. 3.22  The course of the infrapyloric artery should be confirmed before heading to the root of the right gastroepiploic artery. As described in Fig. 3.18, the infrapyloric artery and vein branch resemble an antler and have a mesentery connected to the bulbous part of the duodenum, although narrow (for descriptive convenience, the “superior and inferior duodenal mesentery”). Lymph nodes are rarely seen in this mesentery, and in the event that they are, they are not classified as No. 6, so there is no need for

dissection. As such, this mesentery should be preserved in pylorus-preserving gastrectomy, but in usual distal gastrectomy, regardless of whether the Roux-en-Y or the Billroth-I reconstruction technique is used, it is better to resect the mesentery along the duodenal wall because it is necessary with either technique to “lengthen the neck” of the duodenal bulb. First, the most distal branch is ligated and cut near the wall to release the edge of the mesentery

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Distal branch of infrapyloric a. (ligated)

Infrapyloric a.

R gastroepiploic a.

R gastroepiploic a.

Fig. 3.23  When lifting the pylorus, a V-shaped connective tissue (containing nerve fibers) with the right gastroepiploic artery located at the apex is seen. Forceps are inserted from the apex under the connective tissue. After the right and left sides of the triangle are dissected with electrocautery, the root of the right gastroepiploic artery emerges behind. Upon dissection of the left side, care must be taken to accurately determine the margin of the suspended pancreatic parenchyma because it might be

ascending more than expected. If the pancreatic parenchyma is mistaken for fat and is accidentally transected, a distinct type of bleeding occurs. It is better to switch to suture hemostasis because electrocoagulation only makes the wound deeper. Inadvertently damaging the pancreas at this point would cause postoperative pancreatic leakage. The surgeon and first assistant should always proceed while confirming “This is fat, this is pancreas!”

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54 Fig. 3.24  When the tension caused by the connective tissue is released, the right gastroepiploic artery is stretched and the infrapyloric artery branching the root of the gastroepiploic artery can be confirmed [9]. This artery is then isolated with dissection forceps, ligated with 3-0 Vicryl, and divided

Fig. 3.25  The right gastroepiploic artery is divided at its root after double ligation with 3-0 Vicryl. The gastroduodenal artery becomes the anterior superior pancreaticoduodenal artery after branching off the right gastroepiploic artery and immediately dives into the pancreatic parenchyma. Lifting the pyloric area shows the branching of the right gastroepiploic artery clearly, and it looks as if the artery is sticking out of the pancreatic parenchyma

Infrapyloric a.

Gastroduodenal a.

R gastroepiploic a. Infrapyloric a. (root)

3  Distal Gastrectomy Fig. 3.26 When looking at the deployed mesentery after dissecting the root of the right gastroepiploic artery, the two arterial stumps appear aligned. To lengthen the neck of the duodenal bulb, the remaining branches of the infrapyloric artery and vein are ligated and divided one at a time along the duodenal wall and beyond the pyloric ring. In this way, the lymph nodes along the infrapyloric artery are dissected [10]

55

Infrapyloric a. & v.

Infrapyloric a. (ligated)

R gastroepiploic a. (ligated)

R gastroepiploic a. (root)

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56

a

R gastric v. 5

R gastric a.

8a 3

12b

b

a. &

v.

Triangular avascular membrane

uo

rad

Sup

al den

Proper hepatic a. Portal v. R gastric v. R gastric a.

Supraduodenal a.

Axis of symmetry

Supraduodenal v.

R gastroepiploic v.

Infrapyloric v. Infrapyloric a.

R gastroepiploic a. Ant. sup. pancreaticoduodenal a. Sup. mesenteric v.

Fig. 3.27  Dissection of the suprapyloric area: The vessels that play a leading role in this area are the right gastric artery and vein, but it is especially interesting to note the course of the supraduodenal arteries and veins, which play a supporting role. There are three to four supraduodenal veins that gradually anastomose to adjacent branches on their left and often finally merge with the right gastric vein that drains into the portal vein. However, because the anastomotic area is located slightly deeper than the surface of the hepatoduodenal ligament and is difficult to see, these branches seem to suddenly disappear. The supraduodenal arteries arise from the proper hepatic artery separated from the right gastric artery, and they

accompany the venous branches to the duodenum. The branches of the supraduodenal arteries and veins resemble the infrapyloric arteries and veins upside down, which is easier to understand if we consider that these vessels have a symmetrical positional relationship to each other with the duodenum being the axis of symmetry (lower panel of Fig. 3.27b) Because the right gastric vessels head toward the oral side of the pyloric ring and the first supraduodenal vessels head toward its anal side, a triangular avascular mesentery is formed where two vessels form the two sides of the triangle. It is advisable to use this as a landmark when starting dissection of the suprapyloric area (see Fig. 3.29)

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57

Hepatic branch of vagal n.

Lesser omentum

R gastroepiploic a. (ligated)

Greater omentum

Fig. 3.28  An Octopus retractor is placed on the underside of the liver to retract its lateral segment cranially so as to secure an adequate view of the operative field in the lesser curvature of the stomach. A small incision is made in the lesser omentum caudal to the hepatic branch of the vagus nerve to be preserved. This actually means cutting two sheets of peritoneum, similar to the dissection of the greater omentum. Starting from this opening, the lesser omentum is incised along its attachment to the lateral seg-

ment of the liver toward the cardia region. It is advisable for an assistant to cut with electrocautery while guiding with dissection forceps from the other side of the membrane. The surgeon should be aware that an accessory left hepatic artery may be encountered midway, originating from the left gastric artery (the lesser omentum is also the mesentery of the liver, so it is natural for it to include arteries)

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58 Fig. 3.29  When pulling the pylorus caudally, several supraduodenal arteries and veins can be identified, extending from the hepatoduodenal ligament to the upper margin of the duodenum. As shown in the cross-sectional view in Fig. 3.29b, the lesser omentum originates from the front, not from the left margin of the hepatoduodenal ligament. So, when sliding the left index finger from the back of the pylorus, it appears in the front of the hepatic artery (the space indicated by asterisk in Fig. 3.29b), and the triangular mesentery bordered by the right gastric vessels and the first supraduodenal vessels can be stretched from underneath. An opening is made with the electrocautery on the mesentery, and from here, only the peritoneum on the anterior surface of the hepatoduodenal ligament is incised, following the route that goes around the root of the right gastric artery, as indicated by the arrow in Fig. 3.29a

R gastric a. 5

1st branch of supraduodenal a. & v.

R gastric a. & v.

al a. & duoden

v.

Supra

* Proper hepatic a.

Omental bursa 8a

B PV

Common bile duct Foramen of Winslow IVC

Pancreas

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R gastric a.

Proper hepatic a.

R gastric v. No.5 LN

Fig. 3.30  Dissection of the No. 5 lymph nodes: The first assistant pulls the pylorus downward and to the left to cause the pedicle of the right gastric vessels to be stretched. Using electrocautery, the surgeon scrapes the fat tissue including the No. 5 lymph nodes along the blood vessels down toward the omentum side. The vessels usually run parallel—the artery on the cranial side and the

vein on the caudal side—and the root of the vein is located between the proper hepatic artery and the common bile duct. To avoid confusing the right gastric artery with the hepatic artery, the continuity from the common hepatic artery to the proper hepatic artery should be confirmed before dividing the right gastric artery

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60 Fig. 3.31  The right gastric artery and vein are ligated together at the root and divided. Although the No. 5 lymph nodes were dissected, actually the peritoneum on the back of the vessels remains intact. This is the peritoneum made of the posterior wall of the omental bursa that is folded back at the left margin of the hepatoduodenal ligament and continues as the posterior layer of the lesser omentum (lower panel of Fig. 3.31b), located near the foramen of Winslow at the right border of the omental bursa. By dividing it, the lesser omentum is finally separated from the hepatoduodenal ligament, and a leaf-shaped peritoneal defect occurs to the left of the hepatoduodenal ligament after No. 5 lymph node dissection

Peritoneum remaining after division of rt. gastric a. & v. No.5 LN

3

Stomach 6

6 6

R gastric a. & v. (ligated)

R gastric a. & v. (root) 5 Proper hepatic a. B PV

Omental bursa 8a

IVC

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61

3

Peritoneal defect caused by No.5 LN dissection 3 Supraduodenal a. & v.

5

3

R gastric a. & v. (ligated)

No.8a LN Common hepatic a.

Fig. 3.32  To ensure an adequate margin for transection of the duodenum, one or two supraduodenal arteries and veins are ligated and divided along the wall

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62

R gastric v. R gastric a.

Pyloric ring

Proper hepatic a.

Supraduodenal a. & v.

Direct branches to duodenal bulb 8a Gastroduodenal a. Common hepatic a.

R gastroepiploic a. (root)

Fig. 3.33 In laparoscopic surgery, as the scope is advanced to the back of the omental bursa with the stomach lifted up ventrally, the blood vessels running above

the pylorus are well visualized from the inside. From this angle, the right gastric artery runs on the right and the vein runs the left, side by side

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63

R gastric a. (ligated)

R gastroepiploic a. (ligated) R gastroepiploic a. (root)

Infrapyloric a. (root)

R gastroepiploic v. (root)

Fig. 3.34  To transect the duodenum, a linear stapler is used close to the pyloric ring on its anal side. Because fatal complications can occur if there is closure insuffi-

ciency here, the staple line is reinforced and invaginated by interrupted seromuscular 3-0 Vicryl sutures. The separated stomach is then lifted and flipped to the left

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64

5

Vagus n. (anterior trunk) 3

Caudate lobe 3 1

Vagus n. (posterior trunk)

7 7 9 R gastric a. (ligated)

8a L gastric v.

Supraduodenal a. & v.

R gastroepiploic a. (root)

Fig. 3.35 Dissection of the suprapancreatic lymph nodes: These lymph nodes are dissected by peeling off the peritoneum of the posterior wall of the omental bursa from the hepatoduodenal ligament toward the root of the left gastric artery, along with the lymph nodes attached to it. Prior to the dissection, the Octopus retractor has to be repositioned deeper to retract the caudate lobe of the liver and spread the posterior wall of the omental bursa wide. First, the area of dissection of the retroperitoneum is determined and its upper and lower limits are incised. The retroperitoneum is then detached with forceps and cut

with electrocautery. As shown, the upper limit incision proceeds from the vicinity of the right gastric artery stump toward the root of the left gastric artery, parallel to the upper margin of the pancreas. In the first half of the dissection, the membrane is thin and travels deep, hidden behind the bulge of the common hepatic artery (the common hepatic artery fold), making it difficult to pass through the forceps and advance. In contrast, the second half of the membrane is thickened with fat tissue, which may cause some hesitation in cutting, but it is safe to say that beyond this point there is no danger

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65 Anterior nerve of Latarjet

Posterior nerve of Latarjet Anterior gastric branch

Hepatic branch Liver

Anterior trunk

Posterior gastric branch

Posterior Trunk Celiac branch Stomach

Gallbladder

L celiac ganglion Pancreatic tail Pylorus

R celiac ganglion Celiac plexus Liver

Pancreas

Superior mesenteric plexus Intestinal tract Pancreatic head plexus part 1

Fig. 3.36  Anatomy of the vagus nerve: Because of the rotation of the stomach, the left and right vagus nerves, which are parasympathetic nerves, become the anterior and posterior vagal trunks, respectively, at the level of the esophageal hiatus. The anterior vagal trunk branches to the hepatic branch and the anterior gastric branch (white line and white arrows), which descends along the anterior wall of the lesser curvature while branching off anterior corporeal branches to form the anterior pyloric branch (anterior nerve of Latarjet). On the other hand, the hepatic branch travels transversely to the right, as two to three white cords are located close to the liver attachment of the lesser omentum (a white thickened part called the tense part of the lesser omentum), before dividing into the ascending and descending branches along the proper hepatic artery. A part of the ascending branch reaches the gallbladder along the cystic artery. A part of the descending branch becomes a pyloric branch distributed to the stomach along the right gastric artery; the remainder merges with the branches of the posterior vagal trunk that have run along the common hepatic artery The posterior vagal trunk (black line and black arrows) divides into the celiac branch and the posterior gastric branch at the level of the cardia, and the posterior gastric branch becomes the pyloric branch (posterior nerve of

Latarjet) after giving a number of posterior corporeal branches. The celiac branch descends inside the gastropancreatic fold along the anterior aspect of the aorta and enters the celiac ganglia after dividing into left and right at the origin of the left gastric artery. The splanchnic nerve (a sympathetic nerve) that comes through the diaphragm joins the same ganglia. Nerve fibers (sympathetic + parasympathetic) emerging from the celiac ganglion, after forming the celiac plexus, are distributed along the left gastric artery, common hepatic artery, splenic artery, and superior mesenteric artery toward the stomach, liver, pancreatic tail and spleen, and intestinal tract, respectively. Also, some of the fibers stretch in the lower right direction to form a beltshaped nerve bundle and then enter the uncinate process of the pancreas (pancreatic head plexus part 1) Given the above, it is clear that the hepatic and celiac branches are the most important branches of the vagus nerve to be preserved in pylorus-preserving gastrectomy, and it is particularly essential to ensure that dissection of the celiac branch does not interfere with the merging of the parasympathetic nerve fibers into the celiac plexus. There are, however, variations in the course of the celiac branch, and the celiac branch needs to be sacrificed if it descends in close contact with the stomach wall and enters the celiac ganglion accompanying the left gastric artery

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66

Anterior gastric branch

Posterior gastric branch Celiac branch 7 7 9 8a Gastropancreatic lig.

L gastric v.

Fig. 3.37  The lower limit of the dissection of the posterior wall of the omental bursa corresponds to the upper margin of the pancreas, going slightly upward on the gastropancreatic fold. Care should be taken to separate and lift only the thin peritoneum before dissecting; otherwise, there may be injury to the left gastric vein (coronary vein).

Because this vein can be seen through the gastropancreatic fold when it is spread out, it is advisable to confirm its approximate course in advance. When the first or second assistant pulls the pancreas caudally, the retroperitoneum is stretched, which considerably improves the operative view

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67

a

b

Draining near portal v.– splenic v. confluence

Crossing the anterior surface of common hepatic a. and draining into the splenic v.

c

Crossing the anterior surface of splenic a. and draining into splenic v.

Fig. 3.38  For the left gastric vein, one type travels to the right along the upper rear of the common hepatic artery and directly drains the portal vein or near the portal vein– splenic vein confluence (a) and another type descends straight down along the left gastric artery and, after crossing in front of the common hepatic artery, drains into the splenic vein (b). Sometimes, the vein crosses the anterior surface of the splenic artery and drains into the splenic vein (c). In the case of b or c, because the vein traverses the anterior surface of the common hepatic artery, its root can often be identified in advance. The vein should be

ligated and divided immediately when it is identified. In patients with a lot of visceral fat, it is difficult to identify the left gastric vein and it may be inadvertently cut without being noticed, causing bleeding. In contrast, in type b cases where the vein can be divided early, extreme caution is not needed for No. 8a lymph node dissection. However, when the left gastric vein cannot be identified in the front of the common hepatic artery, this is type a and the No. 8a lymph nodes need to be carefully dissected while keeping in mind the presence of the accompanying left gastric vein

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68

Small branches entering lt. gastric v. from LN

L gastric a. (root)

Peripheral lt. gastric v. (visible through peritoneum)

Portal v.

Root of lt. gastric v.

Fig. 3.39  Proceeding toward the gastropancreatic fold, the No. 8a lymph nodes along the common hepatic artery are dissected. Instead of holding the lymph nodes themselves, it is better to grip the edge of the detached retroperitoneum with forceps and detach the fat tissue including the lymph nodes from the artery. It is safe to insert dissection forceps between the fat tissue and the arterial wall to isolate a dissection layer and dissect it with electrocautery. The dissection advances on the surface of the artery, while maintaining the superficial dissection layer that covers a meshy nerve bundle surrounding the artery. There is a small blood vessel communicating between the No. 8a

Small vessel between LN and pancreatic parenchyma ( * )

lymph nodes and the pancreatic parenchyma (asterisk in Fig. 3.39). This vessel should be ligated or cauterized because it can be a source of bleeding that is difficult to stop when overlooked. If the stump of this blood vessel gets retracted into the pancreatic parenchyma and it becomes difficult to achieve hemostasis, Z sutures with 3-0 Vicryl are applied to stop the bleeding. When the left gastric vein is identified on the way, it is advisable to ligate and divide it early. When passing forceps, care should be taken not to injure small branches entering the left gastric vein from the lymph nodes

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69

Retractor

L gastric v. (ligated)

1 7 9 8a

Loose connective tissue in gastropancreatic lig.

L gastric v. (root)

L gastric a. wrapped in nerve bundle

Celiac plexus

Fig. 3.40  Dissection of the left leaf of the gastropancreatic fold: The second assistant stands to the right of the first assistant (on the side closer to the patient’s head) and retracts the fundus of the stomach cranioventrally with an intestinal retractor. The tip of the retractor is advanced deep enough to reach the upper left corner of the omental bursa and, along with the Octopus retractor, secures the operative field by firmly pressing the gastropancreatic fold from both sides. The first assistant pulls the pancreatic tail caudally, which allows for wide expansion of the left edge of the gastropancreatic fold. (I love exposing the operative field in this area; the gastropancreatic fold, stretched up from the posterior wall of the omental bursa and straightened, is so beautiful!) There are no large vessels here, except for the posterior gastric artery that

emerges from the splenic artery. When the peritoneal incision is extended from the upper edge of the pancreas along the rising edge of the gastropancreatic fold, the loose connective tissue inside is stretched into a thin membrane. When inserting forceps here, it is possible to advance about 3 cm without any resistance. Then, by gently opening the forceps and dissecting the connective tissue with electrocautery, the No. 9 lymph nodes are dissected while still attached to the stomach. The gastropancreatic fold has a cross section of an inverse isosceles triangle with the left gastric artery at its apex; its interior consists of a space covered by a spider web resembling the “retrorectal space,” which I like to call the “retrogastric space”

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70

Posterior layer of lesser omentum

R leaf of gastropancreatic lig.

Posterior wall of omental bursa

Celiac branch of vagal n.

Fig. 3.41  Dissection of the right leaf of the gastropancreatic fold: The retroperitoneum of the posterior wall of the omental bursa turns over and continues as the right leaf of the gastropancreatic fold covering the right diaphragmatic crus, and transitions to the posterior leaf of the previously divided lesser omentum. So, by extending the upper limit incision of the retroperitoneum and dissecting the right leaf of the gastropancreatic fold obliquely, the peritoneum of the posterior wall of the lesser curvature in the upper body of the stomach is dissected continuously. Then, the

loose connective tissue inside the gastropancreatic fold is separated with dissection forceps and dissected using electrocautery. This tissue may contain several nerve fibers distributed from the celiac branch to the stomach. If we consider the celiac branch to correspond to the hypogastric nerve, the structure around here is also very similar to that of the retrorectal space. With this, only the left gastric artery wrapped in the armor of the nerve bundle remains

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71

R layer of gastropanc. lig. (cut)

L gastric v. (ligated)

L gastric a.

Celiac plexus

Fig. 3.42  The cord-like tissue that encloses the left gastric artery is spread out and a longitudinal tear is made on it using right angle forceps. From here, by scooping off the nerve bundle several times, it can be separated from the arterial wall and divided with electrocautery. The

nerve fibers are solid and sometimes thick enough to be confused with the left gastric artery. If you are confident enough not to hesitate in cutting them with electrocautery, then you are no longer a beginner in stomach surgery

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Celiac branch of vagus L gastric v. (ligated)

L gastric a. (ligated)

Suprapancreatic LNs dissected en bloc

L gastric v. (root)

L gastric a. (root)

Fig. 3.43  The left gastric artery is ligated and divided at its root. The aggregated No. 7, 8a, and 9 lymph nodes stay attached to the root of the left gastric artery and vein like a flap

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Posterior gastric branch of vagus

Celiac branch

Posterior gastric br. of lt. gastric a. (terminal ascending br.)

Fig. 3.44  The celiac branch of the vagus nerve descending inside the fold is identified and preserved. The posterior gastric branch is divided after coming off at the level of the cardia

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74

Anterior gastric br. of lt. gastric a. (terminal ascending br.) Anterior gastric branch of vagus

1

8a

3

7 3

Suprapancreatic LNs dissected en bloc

L gastric a. & v. (ligated) R gastric a. & v. (ligated) R gastroepiploic a. & v. (ligated)

Fig. 3.45  Dissection of the lesser curvature in the upper body of the stomach so-called three-layer dissection: The stomach is placed back to its original position and the Octopus retractor is repositioned close to the esophageal hiatus. The first assistant pulls the stomach caudally to stretch the lesser curvature in the upper body of the stom-

ach. The surgeon runs the electrocautery along the border between the omental fat tissue and the anterior wall of the stomach superficially, incising only the peritoneum of the anterior layer along the planned dissection line. On the way, the anterior gastric branch, which comes off the anterior vagal trunk in front of the cardia, is also divided

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75

Anterior gastric branch of vagus

1

Suprapancreatic LNs dissected en bloc

3

8a

Fig. 3.46  The branches of the ascending limb of the left gastric artery entering the anterior wall of the stomach, which cross over the peritoneal incision line, are then ligated and divided along with the accompanying anterior

3

gastric branches of the vagus nerve. Several branches are divided while ascending from the level of the planned dissection line toward the cardia

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76

1 8a

3 3

Fig. 3.47  The intermediate fat layer of the lesser omentum (“flesh”) is scooped with dissection forceps and divided with electrocautery. It is easier to identify the border when holding the fat tissue in the gastric attachment of

the lesser omentum between the left thumb and index and middle fingers while applying force in the direction to peel it off the stomach wall

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77

1

8a

Fig. 3.48  The branches of the left gastric artery entering the posterior wall of the stomach, along with the accompanying branches of the vagus nerves, are ligated together and divided. These vessels are distributed over a shorter

distance compared with the anterior side, and there are also a smaller number of vessels to be dissected. In addition, the peritoneum has already been incised as the right leaf of the gastropancreatic fold

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78

Omental adipose tissue containing No.1 LNs

Suprapancreatic LNs dissected en bloc

1 8a 9

7

Fig. 3.49  The stomach is transected with a linear stapler and the specimen is removed. On the lesser curvature side of the resected specimen, the fat tissue of the lesser omen-

1

tum containing the No. 1 lymph nodes and the flap of the retroperitoneum with the No. 7, 8a, and 9 lymph nodes are attached together in a V shape

3  Distal Gastrectomy Fig. 3.50 Roux-en-Y reconstruction (see Fig. 3.50 through Fig. 3.57): With an imaginary dissection line drawn on the jejunum at approximately 20 cm caudal from the ligament of Treitz, the mesentery is incised after the marginal artery and vein are ligated at a single point and divided. When performing Roux-en-Y reconstruction after distal gastrectomy, the jejunal limb does not need to be pulled up as much and the incision of the mesentery can be minimized

Fig. 3.51  The jejunum is transected with a linear stapler

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3  Distal Gastrectomy

80 Fig. 3.52 Approximately 30 cm of the Roux-limb is measured and a side-to-side anastomosis with the Y limb is performed using a linear stapler. The length of the anastomosis is 40 mm

Supporting suture

Fig. 3.53  The opening for stapler insertion is closed with a single-­ layer, running 4-0 PDS suture. An opening is made on the transverse mesocolon to the left of the middle colic artery and vein, and the jejunum is pulled up via the retrocolic route

3  Distal Gastrectomy Fig. 3.54  The greater curvature corner of the gastric remnant stump is removed with electrocautery to make a small opening. A linear stapler is inserted to make a gastrojejunal side-to-side anastomosis (isoperistaltic, length of anastomosis 60 mm). It is easier first to insert the cartridge arm in the mobile jejunum and then to insert the anvil arm into the stomach

81

82 Fig. 3.55  The opening for stapler insertion is closed with a single-­ layer, running 4-0 PDS suture

Fig. 3.56 The anastomosis is pulled down below the transverse mesocolon, and the gastric remnant is anchored to the mesocolon with three interrupted 3-0 Vicryl sutures

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83

Fig. 3.57  After washing the abdominal cavity, an 8-mm duple drain is inserted into the foramen of Winslow from the right side of the abdomen. The operation is completed by closing the abdominal wall, suturing in three layers

3  Distal Gastrectomy

84 Fig. 3.58 Billroth-I reconstruction (Fig. 3.58 through Fig. 3.67): After completing the procedure as illustrated in Fig. 3.32, a sump clamp is placed on the immediate anal side of the pyloric ring and an intestinal clamp is placed on the duodenal transection line while ensuring an adequate margin for the transection. The duodenum is transected 1–2 mm orally from the clamp with a pointed blade (transecting too close to the clamp may dislodge it and result in deviation of the duodenum). The mucosal surface of the stump is wiped off and cleaned with gauze

Stump clamp Intestinal clamp

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85

Gastric clamp

Stump clamp

Fig. 3.59  After dividing the stomach with a linear stapler, a stump clamp is applied, taking into consideration the diameter of the duodenum and (1) applying the clamp at an acute angle to the stomach stump and (2) ensuring

that the tip of the clamp is not beyond the edge of the stump. Then, the gastric clamp is also applied, the part of the stomach stump that protrudes from the stump clamp is transected, and the stump clamp is removed

86 Fig. 3.60 Gastroduodenal anastomosis: An intestinal clamp for anastomosis is applied to the duodenal stump and the clamp is removed. The second assistant supports the stomach clamp and the intestinal clamp, and anastomosis is started. First, a full-layer 4-0 PDS suture is passed on the greater curvature corner in the sequence of inside → out → outside → in and is grasped with mosquito forceps without ligating

Fig. 3.61  In the lesser curvature corner, a 4-0 PDS mattress suture is applied around the staple line in the sequence inside of the posterior wall → out → outside → in → inside of the anterior wall → out → outside → in and is then ligated. One of the threads is grasped with mosquito forceps

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87

Fig. 3.62  An Albert suture is applied to the posterior wall. The surgeon and the first assistant hold the serosa of the stomach and duodenum, ensuring that all layers are passed. After completing the suture along the full length of the posterior wall, the thread on the lesser curvature side is ligated first, and then one of the threads on the contralateral side and the Albert suture are ligated, while the other thread is cut

Fig. 3.63  The Albert suture is then continued on the anterior wall with the same thread. The last few stitches should be placed after removing the intestinal and gastric clamps. After suturing the full length, the thread is ligated

with the thread end that was held with mosquito forceps at the beginning, thus completing the circumferential full-­ thickness suture

88

Fig. 3.64  Additional interrupted seromuscular 3-0 Vicryl sutures are applied, starting from the upper edge of the anterior wall. The correct technique is to suture the stom-

3  Distal Gastrectomy

ach side and the duodenum side one after another as if drawing a “W” with the tip of the needle. (It is important to do this rhythmically!)

3  Distal Gastrectomy

Fig. 3.65  The suture can be continued to a considerable portion of the posterior wall by rotating the anastomosis site. When you feel you cannot go any further, grasp the Fig. 3.66  Then, the anastomosis is rotated in the reverse direction and lifted with the turned thread, while seromuscular sutures are applied to the remaining part of the posterior wall. The corner of the anastomosis adjacent to the staple line is most reliably secured with a 3-point triangular suture

89

last thread with Kocher forceps to pass it behind the anastomosis and cut the rest of the threads

90 Fig. 3.67  If the anastomotic site seems to be under tension, additional duodenal mobilization should be performed (Kocher maneuver). Following mobilization, the hepatic portal vasculature deviates considerably toward the midline, as shown. After washing the abdominal cavity, an 8-mm duple drain is inserted into the foramen of Winslow from the right side of the abdomen. The operation is completed by closing the abdominal wall, suturing in three layers

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4

Total Gastrectomy

Abstract

In this chapter, we work through the total gastrectomy procedure with D2 lymphadenectomy. Because this procedure involves dissection of the No. 11 lymph nodes in addition to the No. 14v and 12a nodes, the pancreas is preserved, while the spleen and splenic artery are removed together. Esophagojejunostomy is performed instrumentally, and Y limb anastomosis is done manually. The standard operation time is 4 h. In Chap. 5, on curative esophagectomy, we discuss dissecting the gastrosplenic ligament while preserving the spleen, although the current convention does not require dissection of the No. 10 splenic hilar lymph nodes (no need for splenectomy) for total gastrectomy with D2 lymphadenectomy. Keywords

Total gastrectomy · D2 lymphadenectomy Roux-en-Y reconstruction

Fig. 4.1  The surgeon stands on the right side of the patient and makes an upper abdominal midline incision extending from the xiphoid process to the left of the umbilicus. The peritoneum is incised to the left of the round ligament of the liver to open the abdomen. If a large xiphoid process obstructs the operative field, we can resect it to widen the field

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_4

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4  Total Gastrectomy

92 Fig. 4.2  After placing a wound retractor, the abdominal cavity is explored including the liver, the pouch of Douglas, and other structures. An Octopus retractor is applied from the right side to cranially retract the lateral segment of the liver. A rib retractor is applied to the right to secure the operative field of view in the left upper abdomen

Fig. 4.3  Following the same procedure described in Chap. 3 on distal gastrectomy, the attachment of the greater omentum to the transverse colon is incised around the midpoint of the greater curvature of the stomach using electrocautery to open the omental bursa. The incision is continued toward the left colic flexure until the left lower corner of the omental bursa is reached

L colic flexure Great omentum

Omental bursa

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93

a Pancreas L border of omental bursa

b Connective tissue behind pancreas

Fig. 4.4  The peritoneum of the posterior wall of the omental bursa is incised along the lower border of the pancreas (a). The pancreas is inverted and, using electrocau-

tery, the exposed cotton-like loose connective tissue behind the pancreas is dissected, as if melting it (b)

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94

Great om

entum

L gastric a.

No.11 LN

s crea

Pan

Splenic a.

Splenic v.

Fusion fascia of Toldt a

urs

lb

ta en

Om

Transverse panc. a.

Post. epiploic a.

Fig. 4.5  Here we can see the dissected layers shown in Fig. 4.4. Behind the pancreas is a fascia formed by pancreatic collision with the abdominal wall and subsequent fusion of the apposed peritoneal membranes (the fusion fascia of Toldt). Here, the proper way to achieve natural layer separation is to enter the layer above the fusion fascia of Toldt, that is, the gap between the subperitoneal fascia (retropancreatic fascia) on the pancreatic side and the fusion fascia (white arrows). For pancreatic displacement, rather than dissecting unidirectionally from the splenic side, it is advisable to start the dissection from the lower border of the pancreas (Fig.  4.4a) because this makes it easier to enter the correct layer and affords a better view of the operative field While dissecting the posterior wall of the omental bursa along the lower border of the pancreas, we may encounter

several blood vessels traveling under the peritoneum. These vessels are the posterior epiploic arteries branching from the pancreatic artery inferiorly and leading to the posterior wall of the omental bursa. They travel within the intermediate fat layer of the greater omentum shared with the pancreas and so are inevitably dissected in this step. (Incidentally, the fact that these arteries are named “epiploic” indicates that the pancreas develops from inside the greater omentum and the anterior leaf of the transverse mesocolon is identical to the greater omentum). These posterior epiploic arteries may sometimes anastomose with the middle colic artery, and blood vessels may then be encountered even when the correct layer is entered for dissection of the omental bursa. Interestingly, in rare cases, the middle colic artery branches from the transverse pancreatic artery or more proximally from the dorsal pancreatic artery

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95

a

Splenocolic lig. (cut)

b

L inf. phrenic a.(esophagocardiac br.)

Ant. trunk of vagus n.

No.2 LN

Fig. 4.6  The surgeon lifts the spleen toward him/herself with the left hand and incises the splenocolic ligament around the lower pole of the spleen (a). The retroperitoneum is incised with electrocautery following a route as close as possible to the spleen. While holding the spleen with the left hand, the surgeon should gradually extend the fingers placed on the lower border of the spleen so that the hand

does not obstruct the operative field (b). Having completed approximately the lower two-thirds of the peritoneal incision, the whole spleen is drawn caudally and the peritoneal incision is extended toward the cardia of the stomach (dotted arrow). This extended incision should pass lateral to the No. 2 lymph nodes located along the esophageal cardiac branch of the left inferior phrenic artery

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96

Spleen

Retroperitoneum (divided)

Splenocolic lig. (divided)

Retropancreatic fascia (connective tissue film)

Fig. 4.7  This is a schematic diagram of the procedure described in Fig. 4.6. The spleen is lifted from its lower pole, keeping the layer of the retropancreatic fascia intact, as indicated by the arrow

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97

a Contour of pancreas tail

Retropancreatic fascia (connective tissue film)

b

Omental bursa

Fusion fascia of Toldt

SMA Fascia of Gerota

Aorta

L adrenal gland

L renal v.

Fig. 4.8  Once liberated from the retroperitoneum, the spleen can be lifted easily. The tail of the pancreas is also lifted together with its loose connective tissue (a). By dissecting this tissue with electrocautery, we can easily enter the layer behind the pancreas without resistance and then

connect to the layer previously accessed from the lower border of the pancreas (arrows in b). A single layer of the retropancreatic fascia, with the appearance of a matted wafer, behind the pancreas indicates that we are proceeding as planned (b)

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98

a Ant. trunk of vagus n.

No.2 LN Esophagocardiac br.

L inf. phrenic a.

Splenic v.

Adrenal br.

L adrenal gland

Inf. mesenteric v.

b

L adrenal gland Gastropancreatic lig.

Fig. 4.9  The connective tissue attached to the anterior surface of the left adrenal gland (a, and the area is shaded in b) should be adequately dissected. Care should be taken to avoid advancing the dissection deeper because the left inferior phrenic artery also gives off a small branch to the

left adrenal gland, and this branch may be damaged and cause bleeding. This now completes the displacement of the pancreas and spleen, and they are immediately returned to their original positions

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Peritoneum on ant. surface of pancreas

R border of omental bursa

Fig. 4.10  Omental dissection proceeds by advancing from the midpoint toward the right until the right border of the omental bursa is identified, which corresponds to the folding line at which the anterior layer of the transverse mesocolon is folded back. This is incised with

Metzenbaum scissors or electrocautery. The dissection continues upward in the same direction, incising the peritoneum that covers the anterior surface of the pancreas all the way to its upper border

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L border of omental bursa (divided in Figs. 4.6 and 4.7)

Foramen of Winslow

Omental bursa

Fusion fascia Acc. R colic v.

R border of omental bursa Mid. colic a. & v.

Fig. 4.11  Heading from the right border of the omental bursa toward the right colic flexure, the omental attachment to the transverse colon is divided using electrocautery (a). By applying an appropriate amount of

Post. epiploic a.

countertraction, we can enter the layer above (on the omental side of) the fusion fascia that is formed by fusion between the greater omentum and the transverse mesocolon (b)

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101

Gastrocolic trunk of Henle SMV No.14v

Acc. R colic v. Transverse mesocolon (fusion fascia)

Fig. 4.12  The right transverse mesocolon needs to be dissected more deeply than for distal gastrectomy (Chap. 3) to dissect the No. 14 lymph nodes adjoining the superior mesenteric vein (SMV). By pulling the transverse colon caudally, the second assistant expands the mesoco-

lon into a fan shape, with the gastrocolic trunk of Henle as the pivot of a fan. The surgeon proceeds by dissecting the layer above the fusion fascia and, when reaching the anterior surface of pancreas, carefully incises the fusion fascia to transit to the next layer

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a

Fusion fascia of Treitz

3 Fusion fascia between great omentum and ant. surface of duodenum 1 Fusion fascia between great omentum and transverse mesocolon

*

Fusion fascia of Toldt

2 Fusion fascia between horizontal part of duodenum and transverse mesocolon

b R gastroepiploic v.

ASPDV

3 Fusion fascia between great omentum and ant. surface of pancreas (mesogastrium) 1 Fusion fascia between great omentum and transverse mesocolon

Gastrocolic trunk of Henle No.14 v.

Fig. 4.13  This is a schematic diagram of the latter half of the procedure described in Fig. 4.12. A sagittal cross section at the level of the descending part of the duodenum shows five fusion fascias (a). The three fusion fascias numbered ➊, ➋, and ➌ fail to merge at the margin of their attachment to the transverse mesocolon and form a gap containing loose connective tissue (asterisk). Once the omental dissection reaches the anterior surface of the pancreas, this gap is entered so that the transverse mesocolon can be fully peeled off the anterior surface of the pan-

creas. A sagittal cross section at the level of the gastrocolic trunk of Henle (the pivot of a fan) (b). In distal gastrectomy (Fig. 3.20) where we intend to go no further than dissecting the No. 6 lymph nodes, the fusion fascia is penetrated to reach the anterior surface of the pancreas. For total gastrectomy, however, we intend to dissect the No. 14 lymph nodes, so the fusion fascia on the side of the transverse mesocolon is incised and the dissection is advanced toward the SMV

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103

R gastroepiploic v.

No.14v LN

Henle

Mid. colic v.

Acc. R colic v.

Cutting line of fusion fascia

Fig. 4.14 Eventually, the bluish SMV can be seen through the membrane. By activating the electrosurgical probe or using it as a spatula, the surgeon removes the fat tissue around the SMV including the No. 14 lymph nodes and identifies the middle colic vein and the gastrocolic

trunk of Henle draining into the SMV. The space between these vessels should also be cleared completely. The second assistant should take great care when pulling the transverse colon so as to avoid tearing the exposed veins

4  Total Gastrectomy

104 Fusion fascia (cut, *) Fusion fascia (cut, *)

No.14v

Mesoduodenum

*

*

Henle SMV

Fig. 4.15  This is a schematic diagram of the procedure for dissecting the No. 14v lymph nodes. The dissection shown in Fig. 4.13 is deepened toward the anterior aspect of the SMV. To clearly expose the root of the middle colic vein and the origin of the gastrocolic trunk of Henle from the SMV, the surrounding fat tissue with lymph nodes included should be carefully removed. The membrane held with the forceps is the mesogastrium detached from

the anterior surface of the pancreas, and the No. 14v lymph nodes attached to its tip are removed together with this membrane. Although en bloc dissection of the No. 14v and No. 6 lymph nodes can be achieved by continuing the dissection upward beyond the confluence of the anterior superior pancreaticoduodenal vein (ASPDV), it is advisable to remove these nodes separately so that they can be distinguished later

4  Total Gastrectomy

105

Infrapyloric v.

*

R gastroepiploic v. ASPDV

Fig. 4.16  Dissection of the No. 6 lymph nodes follows the same procedure as in distal gastrectomy (Chap. 3). The first assistant pulls the gastric pylorus cranially, while the second assistant pulls the transverse colon caudally to widely expose the region. Using electrocautery, the surgeon peels off the fatty connective tissue around the right gastroepiploic vein with lymph nodes included. After con-

firming that the confluence of the ASPDV has been passed, the right gastroepiploic vein is isolated with right angle dissection forceps, ligated with a 3-0 Vicryl suture, and divided. If the confluence of the infrapyloric vein is located at a lower level, only the right gastroepiploic vein may be dissected right above the confluence (asterisk) at this point and the infrapyloric vein may be dealt with separately

4  Total Gastrectomy

106

R gastroepiploic v. (ligated)

R gastroepiploic v. (root)

Fig. 4.17  The next step is to expose the root of the right gastroepiploic artery. In some patients with metastasis-­ positive No. 6 lymph nodes, swollen lymph nodes are firmly attached to the pancreatic parenchyma and sur-

round the root of the right gastroepiploic artery. The lymph nodes are lifted from the pancreatic parenchyma as much as possible with forceps, and the intervening fibrous connective tissue is dissected with electrocautery

Infrapyloric v.

Gastroduodenal a.

Fig. 4.18  Once the root of the right gastroepiploic artery arising from the gastroduodenal artery has been exposed, the vein is divided at its root after double ligation with 3-0 Vicryl

4  Total Gastrectomy

107 R gastroepiploic a. (ligated)

a

Infrapyloric a.

Gastroduodenal a.

Adipose tissue including infrapyloric a.

R gastroepiploic a. (root)

R gastroepiploic v. (ligated)

b

Branch of infrapyloric a.

Adipose tissue including infrapyloric a. (dissected)

Infrapyloric a. (ligated) Infrapyloric a. (root)

Fig. 4.19 The infrapyloric artery usually originates within the vicinity of the root of the right gastroepiploic artery, as mentioned in Chap. 3 on distal gastrectomy, but it may also diverge from the gastroduodenal artery (a and b). When metastasis to the No. 6 lymph nodes is sus-

pected, the infrapyloric artery should be ligated and divided at its root without hesitation. After ligation and division of the branches of the infrapyloric vessels along the duodenal wall, the “inferior mesoduodenum” is resected together with the No. 6 lymph nodes

4  Total Gastrectomy

108

a

Ant. gastric br. of vagus n.

b

Post. gastric br. of vagus n. Proper hepatic a. Lesser omentum

Es

B Foramen of Winslow

Ant. gastric br. of vagus n.

PV

Omental bursa Ao IVC

Fig. 4.20  We now move on to dissection of the suprapyloric area. A small incision is made at the right upper corner of the lesser omentum. A dissection clamp is inserted through the incision to guide electrocautery dissection of the lesser omentum along its attachment to the lateral segment of the liver. When the esophagus is reached, the dissection is continued across the front of the esophagus until it connects with the retroperitoneal incision line (asterisk in

a) along the lower border of the spleen. Beyond the esophagus, the dissection is advanced in an almost vertical direction. Two membranes are dissected before the esophagus is reached, and only one membrane is dissected after that (b). In front of the esophagus, the dissection line crosses slightly beneath the diaphragm-serosa transition. The first assistant pushes the spleen (and the bowel if protruded) caudally with the left hand to secure the operative field

4  Total Gastrectomy

a

109 R gastric a. & v.

1st. branch of supraduodenal a. & v.

Divided peritoneum of hepatoduodenal lig.

b

Caudate lobe Lesser omentum (divided) 3 12a

5

3

Supraduodenal a. & v.

Fig. 4.21  Pulling the pyloric portion of the stomach caudally, the surgeon slides the left index finger under the lesser omentum to stretch the mesenteric triangle—the two sides of which are formed by the right gastric vessels and the first branch of the superior duodenal vessels—and makes an opening on it with electrocautery (a). Starting

from the opening, the peritoneum on the anterior surface of the hepatoduodenal ligament is incised while curving to the right until connecting with the lesser omentum incision from the previous step. The superior duodenal vessels crossing the incision line are ligated and divided along the duodenal wall (b)

4  Total Gastrectomy

110

a

No.12p LN

L limbus of hepatoduodenal lig. No.12 LN

R gastric a. & v.

Common hepatic a.

Lesser omentum (divided)

b

R gastric v. Supraduodenal a. & v.

R gastric a.

5

B

12

5

Omental bursa

7 9

12 8a

PV

Fig. 4.22  Now the pyloric portion of the stomach is pulled down along with the lesser omentum. By the earlier step described in Fig. 4.10, the incision along the right border of the omental bursa has already reached the upper border of the pancreas. The incision is now resumed along the left border of the hepatoduodenal ligament until it reaches the foramen of Winslow (a). More precisely, the incision line ascends between the No. 12a (group 2) and

No. 12p (group 3) lymph nodes. This determines the range of dissection of the hepatoduodenal ligament. White arrow (b) indicates the peritoneum on the anterior surface of the hepatoduodenal ligament incised in the procedure shown in Fig. 4.21, black arrow indicates the upper limit of the right border of the omental bursa incised in the present procedure, and dotted line connecting the two arrows indicates the range of dissection of the No. 12a lymph nodes

4  Total Gastrectomy

111

a

12a

Gastroduodenal a.

b 12a 5 12a

5

7 Omental bursa

B

9

8a PV

IVC

Fig. 4.23  The No. 5 and No. 12a lymph nodes are dissected by removing the peritoneum together with the nodes within the dissection range (a). All lymph nodes on

both sides of the proper hepatic artery must be removed, as shown in the cross section (b)

4  Total Gastrectomy

112

a

R gastric a. & v.

R gastric v.

b R gastric a. Proper hepatic a.

Omental bursa

Fig. 4.24  Once the root of the right gastric vessels has been exposed, they are ligated and divided en bloc (a). In the corresponding step in distal gastrectomy (Fig. 3.30), the vessels

are still connected to the peritoneum posteriorly, whereas in the present procedure, the peritoneum has already been dissected (Fig. 4.22) and only the vessels remain as shown in (b)

4  Total Gastrectomy

113

No.5 LN R gastric a. & v.

No.12a LN No.3 LN No.6 LN

R gastroepiploic a. (ligated) R gastroepiploic v. (ligated)

R gastroepiploic a. (root)

Infrapyloric a. (root) R gastroepiploic v. (root)

Fig. 4.25  A linear stapler is used close to the pyloric ring on its anal side to transect the duodenum. The staple line is invaginated by applying interrupted seromuscular 3-0 Vicryl sutures

4  Total Gastrectomy

114 Lesser omentum

a

Esophagus

L gastric v.

8a

b Post. wall of omental bursa

Post. layer of lesser omentum

Es

B PV AO IVC

Fig. 4.26  Before dissecting the lymph nodes along the upper border of the pancreas, the Octopus retractor must be repositioned deeper to retract the caudate lobe of the liver and spread wide the posterior wall of the omental bursa. First, the range of dissection of the retroperitoneum is determined, as done in distal gastrectomy (Chap. 3), and its upper margin is incised (a). The retroperitoneum of

the posterior wall of the omental bursa turns over at the right border of the esophagus and continues as the posterior leaf of the lesser omentum, which was dissected in an earlier step. Therefore, by extending the upper limit incision of the retroperitoneum to the area in which it turns over, we can dissect the peritoneum of the right border of the esophagus continuously (b)

4  Total Gastrectomy

115 Post. trunk of vagus n.

Divided peritoneum of post. wall of omental bursa

3

1 7 9

11P

8a Gastropancreatic lig.

L gastric v.

Fig. 4.27  The lower limit incision of the retroperitoneum proceeds along the upper border of the pancreas until the tail of the pancreas is reached. The first or second assistant firmly pulls the pancreas caudally to apply tension to the

retroperitoneum. If the left gastric vein (coronary vein) is identified at this point as it crosses the front of the common hepatic artery or splenic artery, it should be ligated and divided

4  Total Gastrectomy

116

a

Post. gastric a. Adipose tissue including No.11d LNs

L gastric a. wrapped in nerve bundle

Common hepatic a.

L gastric v. Lesser omentum

b

Om

ent

8a PHA

al b

urs

a

7 9

B PV

Fig. 4.28  Proceeding toward the root of the left gastric artery, the No. 8a lymph nodes along the common hepatic artery are dissected. The same procedure should be followed as described for distal gastrectomy (Fig. 3.39). The nerve bundle surrounding the artery may be preserved for prophylactic lymphadenectomy. But when lymph node

metastasis is suspected, the nerve bundle should be removed and therefore dissection should be carried out in a slightly deeper layer. The left gastric vein is ligated and divided as soon as it is identified during dissection (a). Cross section of the dissection procedure (b)

4  Total Gastrectomy

117

L gastric v. (ligated)

8a No.9

No.11p

7

Adipose tissue including No.11d LNs

7 Root of L gastric a.

Splenic a.

L gastric v. (root)

Celiac plexus

Fig. 4.29  The No. 9 and No. 11p lymph nodes are dissected by proceeding with peri-arterial dissection extending from the celiac artery to the splenic artery. The dissection continues to the vicinity of the origin of the posterior gastric artery. Between the common hepatic artery and the splenic artery is a band-like nerve bundle connecting the celiac plexus and the superior mesenteric

plexus. When metastasis to the No. 9 lymph nodes is suspected, the layer in which the arterial wall is exposed should be dissected with electrocautery and resected along with the nerve bundle. It should be noted that the root of the splenic artery may be excessively twisted to the right, to such an extent that it can be mistaken for an enlarged lymph node

4  Total Gastrectomy

118

a

L gastric a. (ligated)

8a 7 7

Post. gastric a. (ligated)

9 11p

Post. gastric a. (root) Celiac br. of vagus n.

L gastric a. (root) R crus of diaphragm

b

LGA Post. gastric a. CHA Caudal panc. a. Dorsal panc. a.

Great panc. a.

Fig. 4.30  After arising from the celiac trunk, the splenic artery travels curving slightly to the right until it reaches the upper border of the pancreas, from where it undulates twice while maintaining almost the same thickness before entering the splenic hilum (b). It usually gives off the dorsal pancreatic artery before reaching the upper border of the pancreas, the posterior gastric artery from the first peak, and the great and caudal pancreatic arteries from the last two troughs, although variations are common and

some branches may even be absent. For the final step in No. 9 lymphadenectomy, the root of the posterior gastric artery is exposed, ligated, and divided, and then ligation and division of the left gastric vessels follows. Also, the loose connective tissue inside the gastropancreatic fold is dissected toward the cardia of the stomach at the layer where the diaphragmatic crura are exposed (a). In parallel, the left leaf of the gastropancreatic fold (small arrow in Fig. 4.31a) is also incised

4  Total Gastrectomy

119

Ant. trunk of vagus n. L inf. phrenic a.

Post. trunk of vagus n. (divided)

Fig. 4.31  The Octopus retractor, which has been applied deeply to retract the caudate lobe, is repositioned close to the esophageal hiatus to push away the lateral segment of the liver that is overlying this area. With the surgeon’s left index finger placed behind the abdominal esophagus and

the cardiac part being pulled caudally, the esophageal wall is trimmed. After identifying the boundary with the esophageal muscle layer, the vagus nerve and other cord-­ like structures are separated with right angle forceps and divided with electrocautery

120

Fig. 4.32  The surgeon’s left index finger is flexed like a hook and placed under the esophagogastric junction to stretch the abdominal esophagus. Starting from the dissection edge of the peritoneum on the diaphragmatic side, the thin membrane surrounding the esophagus is divided with slightly opened Cooper scissors. A surprisingly long

4  Total Gastrectomy

“neck” can be obtained this way. Although this is a safe procedure, inadvertently damaging the muscular layer necessitates an otherwise unnecessary advancement of the dissection orally and provides only a limited margin for anastomosis, so this should be done to a moderate extent only

4  Total Gastrectomy

Drawstring purse clamp

Fig. 4.33  A purse-­string instrument is applied and a 2-0 nylon suture with straight needles at both ends is passed

121

4  Total Gastrectomy

122

Stump clamp

Esophageal clamp

Fig. 4.34  After placing an esophageal clamp 2–3  cm orally from the purse-string instrument and a stump clamp on the anal side of the instrument while pulling the stomach caudally, the esophagus is transected with Cooper scissors along the instrument. If the transection line is too

close to the instrument, the esophageal stump will fall into the instrument immediately after transection. An appropriate margin is one that is almost equal in width to that of the blade of the Cooper scissors. The specimen is now ready to be excised unless the spleen is also to be removed

4  Total Gastrectomy

Fig. 4.35  The purse-string instrument is removed and the esophageal stump, including the mucosal and muscular layers, is grasped with three pairs of intestinal grasping forceps. The second assistant should be ready with a suction tube in case of gastric juice leakage after the instru-

Fig. 4.36  With two pairs of intestinal grasping forceps held by the first assistant and one held by the surgeon, the esophageal opening is expanded to form a triangle into which the anvil of a 25-mm circular stapler is inserted. When the purse-string suture is tied, the first assistant should hold the anvil shaft with right angle forceps to prevent the purse portion from sliding upward

123

ment is opened. If a purse-string suture is placed on the esophageal mucosa on the other side, that part should be cut as small as possible and removed. An additional three or four interrupted sutures are placed slightly to the outer side of the existing suture for reinforcement

4  Total Gastrectomy

124 Post. gastric a. (root) Adipose tissue including No.11d LNs Esophagus

Omental bursa Peritoneum

L adrenal gland

L gastric a. (root) Splenic a.

l

tai

r

nc

Pa

s ea

Post. gastric a. (ligated)

Sto (po mach ste rior wa

ll)

Esophagus stump

Fig. 4.37  We now move on to dissection of the No. 11 lymph nodes. After transection of the esophagus, the specimen (stomach and spleen) is barely connected to the pancreatic tail by the splenic vessels, and therefore, it can be turned over and drawn out of the wound, as shown. The

L gastric a. & v. (ligated)

splenic artery is ligated and divided proximal to the stump of the root of the posterior gastric artery. The suture thread on the resection side is kept long enough so that it can later be pulled and grasped with mosquito forceps

4  Total Gastrectomy

125

Splenic a.

Adipose tissue including No.11d LNs

Great panc. a.

Fig. 4.38  The first assistant holds the spleen and pancreas and twists them so that the upper border of the pancreas can be seen from the front. The surgeon dissects the No. 11 lymph nodes by removing the fatty connective tissue attached to the splenic artery, with the lymph nodes included, as cleanly as possible. A pair of thin-tipped forceps, such as Kelly pediatric forceps, is inserted between Fig. 4.39  The fatty connective tissue becomes wider as it approaches the splenic hilum, extending from the anterior surface of the pancreatic tail toward its lower border. If the caudal pancreatic artery is encountered on the way, it should be ligated and divided. Among the branches of the splenic artery leading to the pancreas, these are the two major vessels we need to ligate. If other small venous branches are identified, we should also ligate and divide them, even though this is a somewhat troublesome procedure

Caudal panc. a.

the pancreas and fat tissue to isolate a dissection layer, and the layer is dissected with electrocautery. If the splenic artery was divided proximal to the posterior gastric artery, the dorsal pancreatic artery is likely to be preserved. In this case, the first vessel encountered in this dissection procedure is the great pancreatic artery, which should be ligated and divided as soon as it is identified

126

4  Total Gastrectomy

Splenic v.

Splenic a.

Fig. 4.40  Finally, the splenic vein is ligated and divided close to the pancreatic tail and the specimen is excised. The splenic vein should be preserved as long as possible to prevent congestion of the pancreas

4  Total Gastrectomy

127

Stump clamp

Fig. 4.41  For Roux-en-Y reconstruction, the transection line is determined approximately 20 cm distal to the ligament of Treitz, which is far enough away from the root of the mesojejunum (so that the jejunum can be lifted as high as possible) and where the space between blood vessels is as wide as possible. After a single pair of the marginal artery and vein is ligated and divided and the mesojeju-

num is incised, the straight arteries and veins within the range 1 cm proximal and 4 cm distal to the planned transection line are ligated and divided. An intestinal clamp and a stump clamp are placed on the proximal and distal sides of the planned transection line, respectively, and the intestine is transected along the intestinal clamp

4  Total Gastrectomy

128 Fig. 4.42  An opening is made on the transverse mesocolon to the left of the middle colic vessels and the jejunum is lifted via the retrocolic route. If the spleen is preserved, it is advisable to have the blind end of the jejunum facing to the left to avoid torsion of the mesentery (a). If the spleen has been removed, the left colic flexure may be drawn into the large space formed under the left diaphragm, causing torsion of the Roux-limb and its bending at the anastomosis (b), and therefore, the blind jejunal end should be made facing to the right to prevent this torsion (c and d)

a

b

c

d

4  Total Gastrectomy Fig. 4.43  The clamp on the Roux-limb stump is removed and the stump is fully dilated using an anastomosing intestinal clamp. The body of the circular stapler is carefully inserted into the stump to avoid tearing the intestinal wall and is then advanced 5–6 cm. With the intestine grasped by hand and using gauze to prevent slippage, the center rod is pulled out on the antimesenteric side, moved toward the esophageal stump, and then inserted firmly into the anvil shaft (a). The stapler is tightened while confirming that there is no intestinal torsion or inclusion of other tissue. Before tightening the stapler completely, the mesentery is expanded once to make sure that the intestinal wall on the medial side (circled area in b) is not compressed. Note that excessively pulling the jejunum while tightening the stapler will result in a narrow anastomosis. After firing, the body of the stapler is pulled out gently so as not to apply tension to the anastomosis

129

a

b

130 Fig. 4.44  The stump is trimmed down with a linear stapler approximately 3 cm from the anastomosis, sparing one or two straight vessels. After completion of the anastomosis, a nasogastric tube is inserted up to about 15 cm distal from the anastomosis. This tube should be removed the following morning

Fig. 4.45  An anastomosing intestinal clamp is applied to the proximal jejunum and the Y-limb is end-to-side anastomosed with the jejunum 40–50 cm distal from the esophagojejunostomy site. Repair of the mesojejunum and fixation between the transverse mesocolon and the Roux-limb should also be performed

4  Total Gastrectomy

4  Total Gastrectomy

Fig. 4.46  After washing the abdominal cavity, an 8-mm duple drain is inserted into the subphrenic space via the left abdominal wall and a second such drain is inserted

131

into the foramen of Winslow via the right abdominal wall. The operation is completed by closing the abdominal wall, suturing in three layers

5

Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

Abstract

This chapter describes Ivor Lewis esophagectomy for treatment of middle to lower esophageal cancer. The operation consists of two parts: abdominal manipulation is carried out first to construct the gastric conduit; then after thoracotomy, esophagectomy is followed by esophagogastrostomy. Standard operation time is 5 h.

5.1

 art I: Abdominal P Manipulation

Keywords

Ivor Lewis esophagectomy · Esophageal cancer · Gastric conduit · Thoracotomy Abdominal manipulation

Fig. 5.1  The patient is placed in the supine position and the operative procedure starts with abdominal dissection and gastric conduit construction. The surgeon stands on the right side of the patient and makes an upper abdominal midline incision extending from the xiphoid process to the umbilicus. The peritoneum is incised to the left of the round ligament of the liver to open the abdomen. A wound retractor is then placed and exploration of abdominal organs commences. A rib retractor is placed on the left side and the liver is retracted cranially with an Octopus retractor to secure visualization of the operative field

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_5

133

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

134

Interrupted gastric arcade

Attachment to transverse colon Greater omentum

Arcade of epiploic a.

Greater omentum to be added to gastric conduit

Fig. 5.2  The greater curvature of the stomach is examined to determine the presence or absence of the gastric arcade, which is formed by anastomoses between the left and right gastroepiploic arteries and veins. As shown,

when a clear arcade cannot be identified (about 10% of all cases), we need to use the gastroepiploic arcade (circled) and prepare a gastric conduit attached by a larger amount of greater omentum

5.1 Part I: Abdominal Manipulation

135

Root of R gastroepiploic a. & v.

Epiploic a. & v.

R border of omental bursa

Greater omentum (divided)

Ultrasonically activated device

Fig. 5.3  After the omental bursa is entered from the midpoint of the greater curvature of the stomach, the omental dissection proceeds toward the infrapyloric area. The gastroepiploic arteries and veins must be ligated or coagulated with an ultrasonically activated device (USAD) before crossing these vessels. The omental dissection is then advanced across the right border of the omental bursa, at which point the peritoneum is penetrated, up to

the vicinity of the root of the right gastroepiploic artery and vein. The right gastroepiploic vessels are the lifelines for the gastric conduit. To avoid damaging these vessels from excessive tension during the subsequent lifting procedure, the omental dissection must be stopped far enough away from the vessels to preserve the supporting perivascular tissue

136

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer Surgical laparotomy sponge

Gastrosplenic lig.

L gastroepiploic a. & v.

Splenocolic lig.

L colic flexure

Fig. 5.4  The operative field is then shifted to the left and the omental dissection is continued, but this time toward the left colic flexure. When the dissection has approached the splenocolic ligament, a surgical laparotomy sponge is placed behind the spleen to bring the gastrosplenic ligament to a shallower level. The omental dissection is con-

tinued toward the lower pole of the spleen until the left gastroepiploic artery and vein are encountered. These vessels are then ligated and divided. In overweight patients, there is particularly thickened fatty connective tissue in this area

5.1 Part I: Abdominal Manipulation

137

a

Short gastric a.

L gastroepiploic a.

Gastric wall

Epiploic a.

b

Gastrosplenic lig. (divided) L border of omental bursa

L gastroepiploic a. (root)

Splenocolic lig.

Fig. 5.5  The course of the short gastric arteries is highly variable in relation to the branching pattern of the splenic artery at the hilum of the spleen. The splenic artery usually divides into the superior and inferior branches at a distance slightly away from the hilum, and each of the branches then gives off several further branches to the spleen. In the most common type, the lowermost branch

gives off the left gastroepiploic artery, while the other upper branches give rise to short gastric arteries (a). We should keep this basic pattern in mind when carrying out the subsequent procedure. There are usually about five short gastric arteries. After dividing the gastrosplenic ligament, the left border of the omental bursa is exposed (b)

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

138 Gastrosplenic lig.

Short gastric a.

L gastroepiploic a. (root)

Fig. 5.6  With the gastrosplenic ligament held between the left index and middle fingers and stretched, the short gastric arteries are ligated or coagulated with the USAD and dissected on the spleen side. Considering vasculariza-

tion of the gastric conduit, it would be safer to preserve as much fatty connective tissue on the greater curvature as possible, although dissecting the tissue too close to the spleen carries the risk of injuring the spleen

5.1 Part I: Abdominal Manipulation

139 Gastrosplenic lig.

L border of omental bursa

L gastroepiploic a.

s crea Pan

Fig. 5.7  After approximately the lower two-thirds of the short gastric arteries have been dissected, the surgical laparotomy sponge placed behind the spleen is removed. This causes the spleen to sink and the remaining upper one-third of the gastrosplenic ligament is stretched by the weight of the spleen, making it easier to dissect the remaining one or two short gastric arteries. We must take

care here because the gastrosplenic ligament gets narrower as it approaches the upper pole of the spleen, with the short gastric arteries also getting shorter and thinner. After dissecting the uppermost short gastric artery, the dissection continues along the fundus of the stomach while cutting the retroperitoneum, up to the vicinity of the left border of the abdominal esophagus

140

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

Ant. vagal trunk

* Lesser omentum

L gastric a. & v.

Fig. 5.8  We then move on to the lesser curvature side. The stomach is pulled caudally to stretch the lesser omentum and identify the right gastric artery and vein, which are to be preserved. Starting far enough away from the root of these vessels, the lesser omentum is divided toward the right border of the abdominal esophagus using electro-

cautery. When the esophagus is reached, the dissection is continued across the peritoneum in front of the esophagus but quite close to the diaphragm until it connects with the retroperitoneal incision line (asterisk) extending from the fundus of the stomach

5.1 Part I: Abdominal Manipulation

141

a Incision in lesser omentum R layer of gastropancreatic lig.

L gastric v.

L layer gastropancreaticlig

b

Fig. 5.9 The Octopus retractor is then repositioned deeper to retract the caudate lobe of the liver and spread wide the posterior wall of the omental bursa. With the stomach being pulled to the left to spread the gastropancreatic fold, a V-shape retroperitoneal incision is made, the apex of which is the left gastric artery/vein. The right part of the V-shape incision is advanced superiorly above

the crus of the diaphragm that forms the right margin of the aortic hiatus until it connects with the lesser omental incision (a), while the left part the incision is advanced toward the upper end of the gastrosplenic ligament or the left upper corner of the omental bursa. When the posterior gastric artery is encountered, it should be ligated and divided (b)

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

142

L gastric v. (cut)

Post. gastric a.

L gastric v. (root)

Fig. 5.10  The fatty connective tissue surrounding the left gastric artery and vein containing the No. 7 lymph nodes is dissected toward the root of the vessels using electrocautery. The shield formed by nerves extending from the celiac plexus and surrounding the left gastric artery should

be scooped with dissection forceps and dissected with electrocautery. The exposed roots of the left gastric vessels are ligated and divided. The artery should be double-ligated

5.1 Part I: Abdominal Manipulation

143

Loose connective tissue in gastropancreatic lig. L crus of diaphragm L gastric a. (cut)

L inf. phrenic a.

R crus of diaphragm

Celiac br. of vagus n.

L gastric a. (root)

Fig. 5.11 The loose connective tissue intervening between the anterior aspect of the crus of diaphragm and the cardiac portion of the stomach is dissected toward the esophageal hiatus. This loose connective tissue corresponds to the “content” of the gastropancreatic fold and appears like a space covered by a spider web (and also resembles the “retrorectal space”). We should not hesitate when dissecting this tissue; do not be too careful in known avascular areas like this if you do not want to be underestimated! In front of the crus of the diaphragm is the

abdominal branch of the vagus nerve coursing longitudinally toward the celiac plexus. This nerve can be dissected at an appropriate point because it cannot be preserved anyway; the main vagal trunk will be dissected later during thoracic manipulation As the connective tissue containing the No. 1 and 2 lymph nodes is shaved off with electrocautery to expose the muscle fibers of the bilateral crura of the diaphragm, the contour of the esophageal hiatus emerges gradually, appearing like the collar of a kimono

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

144

a

Esophageal muscular layer

No.110 LN

No.111 LN

Adventitia

Pleura Diaphragm Peritoneum

L crus R crus ICB

Stomach muscle layer

*

Sup. phrenicoesophageal membrane

Int. phrenicoesophageal membrane

b

Pericardium

R parietal pleura Azygos vein

Descending thoracic aorta

Thoracic duct

5.1 Part I: Abdominal Manipulation

Fig. 5.12 Dissection of the inferior mediastinum from the esophageal hiatus (described in Figs. 5.12–5.16): For thoracic manipulation via a thoracotomy through the fourth intercostal space, which is the recommended approach to superior mediastinal dissection, it is reasonable to complete as much inferior mediastinal dissection as possible from the abdominal side. But first let us review the anatomy of the esophageal hiatus, the entrance to the inferior mediastinum. The diaphragmatic muscular bundle forming the esophageal hiatus consists of the right and left crura, which do not directly attach to the esophageal wall and anchor the esophagogastric junction via the fascia. This fascia serves as a suspension that allows for flexible movement of this area and is referred to as the phrenicoesophageal membrane

145

The phrenicoesophageal fascia is a thin membrane attached to the muscle layer of the stomach, and it is often ruptured inadvertently during manipulation around the hiatus. In the right side of the esophagogastric junction, do not be concerned about finding a space after cutting the thin membrane—you did not penetrate the thorax. This space is the infracardiac bursa (ICB) [11]. The ICB is a closed space formed by separation from the cranial part of the omental bursa in the embryo and is located on the right alongside the esophagus and on the cranial side of the diaphragmatic crus (asterisk in (a)) The basic structure of the inferior mediastinum can be considered a rectangular column surrounded by the pericardium on the upper side, the descending thoracic aorta on the lower side, and the parietal pleura on the right and left sides, through which the esophagus passes (b)

146

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

Folded lateral segment of liver

L int. phrenic v. Pericardium L parietal pleura

No.110 LN

No.111 LN

L inf. phrenic a.

Esophagus

Fig. 5.13  When the lateral segment of the liver covers a substantial part of the esophageal hiatus and interferes with the view of the operative field, we can dissect the left triangular ligament and the coronary ligament up to the vicinity of the left hepatic vein and reposition the Octopus retractor to retract the lateral segment while folding it, and then proceed with dissection The first assistant inserts an abdominal spatula through the esophageal hiatus to push the pericardium so that the heart can be slightly lifted upward. Another abdominal spatula is used to pull the hiatus to the left so as to widen

the inferior mediastinum. Using the left hand, the surgeon pulls the esophagus toward the abdominal cavity, scooping the connective tissue between the pericardium and the left parietal pleura with dissection forceps and dividing it with electrocautery while keeping the fatty connective tissue containing the No. 110 and 111 lymph nodes attached to the esophagus. As the dissection advances deeper, the spatula is inserted deeper so that the procedure can be performed under direct view. Note that particularly careful manipulation is needed when detaching the left wall to avoid penetrating the left pleura

5.1 Part I: Abdominal Manipulation

a

147

L inf. phrenic v.

Fatty tissue containing No.110 LN

Ant. vagal trunk

b

L inf. phrenic v. (divided)

L inf. phrenic a.

Fig. 5.14  After the dissection has proceeded to a certain extent, the diaphragm is incised ventrally from the esophageal hiatus. First, the left inferior phrenic vein, which runs across the upper margin of the hiatus and drains into the left hepatic vein, is scooped with a clamp, ligated, and divided (a). If bleeding occurs from the diaphragmatic muscular bundles, the USAD or the ligation/division procedure should be used because it is often difficult to achieve hemostasis with electrocautery (b). A roughly

four-finger-width opening will allow for smooth lifting of the gastric conduit attached to the greater omentum. The wider this opening of the esophageal hiatus is, the deeper we can advance the inferior mediastinal dissection. Although the dissection can go up to the bifurcation of the trachea, it is not necessary because we can adequately dissect the No. 107 lymph nodes in this area in the subsequent thoracotomy procedures

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148

R parietal pleura No.112-ao LN

Diaphragmatic muscle bundle (cut edge)

Fatty tissue containing No.110 LN

Esophagus L vagus n. (ant. trunk)

R vagus n. (post. trunk) Descending thoracic aorta

Fig. 5.15  The esophagus is then retracted to the left using an abdominal spatula and the connective tissue between the esophagus and the right parietal pleura is dis-

sected with electrocautery. Do not be concerned about damaging this pleura because the membrane will be incised later during the right thoracotomy procedures

5.1 Part I: Abdominal Manipulation

149 No.110 LN

Proper esophageal a.

R parietal pleura No.112-ao LN L vagus n.

No.111 LN

Thoracic duct

Descending thoracic aorta

Fig. 5.16  The esophagus is then retracted ventrally with the spatula, and the connective tissue between the esophagus and the descending thoracic aorta is dissected while keeping the fatty connective tissue containing the No. 112-ao thoracic para-aortic lymph nodes attached to the esophagus. Being mindful of the possible presence of the

proper esophageal artery, advance the dissection using the USAD while exposing the anterior aspect of the aorta. Do not worry about damaging the thoracic duct because it runs behind the aorta in this area. Completing this procedure marks the end of inferior mediastinal dissection

150

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer Fatty tissue containing No.110 LN No.111 LN

Br. of R gastric a. entering stomach wall

Fig. 5.17  Construction of the gastric conduit: The arcade is ligated and divided ensuring that at least three to four branches of the right gastric artery entering the stomach wall remain intact. With the lesser curvature side of the stomach fully stretched, a linear stapler is applied along

the transection line extending from the point of arcade dissection and passing through the points at which the branches of the left gastric artery enter the stomach wall (arrows)

5.1 Part I: Abdominal Manipulation

151

L gastric a. & v. (cut)

Fig. 5.18  The stomach is transected while securing a sufficient margin for inserting a circular stapler (dotted ellipsis). Additional interrupted seromuscular 3-0 Vicryl sutures are applied to invaginate the staple line

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5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

Duple drain

Fig. 5.19  After washing the abdominal cavity, an 8-mm duple drain is inserted from the left abdominal wall and placed in the subphrenic space. This drain is mainly intended for removal of the pleural wash fluid draining into the abdominal cavity and is to be removed the follow-

ing day. After the gastric conduit and greater omentum are positioned properly without any torsion, the abdominal wall is closed by suturing in three layers to complete the abdominal part of the operation

5.2 Part II: Thoracic Manipulation

5.2

153

Part II: Thoracic Manipulation

III

IV V

Anterior border of latissimus dorsi

M axillary line

Pillow

Fig. 5.20 The patient is repositioned to left lateral recumbency and the right arm is immobilized, with the axillary angle slightly obtuse and the elbow at a right angle. A pillow is placed under the patient, below the lower border of the scapula. The thoracotomy procedure is described in detail here because gastrointestinal surgeons are not generally familiar with it The surgeon stands on the back side of the patient and makes an anterior axillary incision for thoracotomy through the fourth intercostal space. First, the third rib needs to be identified. As the ribs are palpated from upper to lower along

the midaxillary line, the groove suddenly gets deeper and becomes less easily palpable at a certain point. The last palpable rib is the third one. A skin incision is made along the arc extending from the intersection of the third rib and the midaxillary line, through a point one-finger medial from the anterior border of the latissimus dorsi (palpable as a bulge) and then anteroinferiorly toward the fifth intercostal space. In female patients, note that care is needed to avoid damaging the mammary gland. If excessive tension occurs, the curved line may be slightly extended anteriorly from the intersection of the third rib and the midaxillary line

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

154 Fig. 5.21  In the fourth intercostal space, the subcutaneous tissue (on the anterior side) and the latissimus dorsi (on the posterior side) are detached from the fascia of the serratus anterior using electrocautery (a). Once the serratus anterior is exposed (b), the location of the intercostal space to be opened should be confirmed again. The hand is advanced cranially along the thoracic wall and bumps into the clavicle and the first rib (c). The hand is then advanced backward while palpating the second and third ribs. The third and lower ribs are aligned nearly horizontally. Subsequently, the fourth and fifth ribs are palpated

a

Subcutaneous tissue

Latissimus dorsi

b

Serratus anterior

c

Clavicle

1st rib

5.2 Part II: Thoracic Manipulation Fig. 5.22  Starting from the upper border of the fifth rib, the serratus anterior is incised longitudinally along the muscle bundles. The left index and middle fingers are inserted between the serratus anterior and thoracic wall to lift the muscle, and the muscle bundles are divided with electrocautery (a). On the posterior side, the latissimus dorsi is retracted with a flat spatula and the incision is advanced dorsally. When the thoracodorsal artery and vein are encountered under the latissimus dorsi, these vessels should be ligated and divided (b)

155 Pectoralis major

a

IV V VI

Serratus anterior

Latissimus dorsi

b

Thoracodorsal a. & v.

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

156 Fig. 5.23 After one-lung ventilation has been established and the right lung has been collapsed, a thin layer of the external intercostal muscle is dissected using electrocautery, starting from the upper border of the fifth rib (a). Then, thin layers of the internal intercostal muscle and the innermost intercostal muscle are scooped with dissection forceps and divided to expose the parietal pleura (b). After confirming the absence of adhesion between the lung and the pleura, a small area of the pleura is grabbed with forceps and incised with a pointed blade (c). Then, after access to the thoracic cavity has been confirmed, the pleural incision is extended using Metzenbaum scissors

a IV Ext. intercostal m.

V Int intercostal m.

b V

Parietal pleura

c

5.2 Part II: Thoracic Manipulation Fig. 5.24  The incision of the intercostal muscles and parietal pleura is extended in the anterior and posterior directions using electrocautery. After the incision has proceeded to a certain extent, a small rib retractor is placed to gradually widen the wound as the incision continues, while the first assistant protects the lung with gauze held with forceps (a). When the anterior incision approaches the costochondral junction, the incision is oriented superiorly and continued slightly beyond that area. The posterior incision is extended up to the costal angle, which is about 5 cm away from the vertebra (b)

157

a Int./ext. intercostal m.

b

Vertebra

Costal cartilages

Small rib retractor

158

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

Fig. 5.25  The small rib retractor is removed, the upper and lower ribs are protected with a surgical laparotomy sponge, and a large rib retractor is placed. We can avoid rib fracture by slowly turning the retractor handle and widening by one increment at a time. Further widening may be achieved by allowing a longer interval between handle turns. Usually, a wound of 10–12 cm width can be obtained this way

Fig. 5.26  Before going any further, let us quickly review the anatomy of the mediastinum. The vessels, trachea, and esophagus in the mediastinum form a complicated threedimensional crossover structure like a highway junction, and their positional relationship varies depending on the angle from which they are viewed. Also, during esophageal surgery, a “twist” can occur and cause anterior-posterior and/or left-right reversal of their positions. For example, when using a regular right thoracotomy approach, we tend to assume that we have a view of the mediastinum from the exact right side. However, once the right lung is retracted anteriorly through thoracotomy, then we will be viewing the mediastinum from its posterior side. Also, when the hilum of the right lung is significantly displaced (“twisted”) by releasing the “tension” generated by the azygos vein, the posterior aspect (membranous part) of the trachea and the dorsal surface of the heart are exposed, and eventually the posterior aspects of the left bronchus and vessels constituting the left hilar vasculature, such as the left inferior pulmonary vein. Because dissection of lymph nodes in the left side of the superior mediastinum (e.g., No. 106-recL, 106-tbL, and 109-L) is required during esophageal cancer surgery, we need to get used to the uncomfortable feeling of “viewing the posterior side of the left mediastinum through a right thoracotomy” This and subsequent illustrations of the mediastinum (Figs. 5.26–5.28) are designed to help surgeons perform image training, where the mediastinum is placed vertically (in its natural position) in a fixed right oblique frontal view, which most clearly shows the entire

Large rib retractor

three-dimensional crossover structure, with small increments of “twist” applied In this first figure in the series, we see the non-twisted state. The right lung is cut off at the hilum. The mediastinum, which is seen through the parietal pleura after right thoracotomy, corresponds to the area surrounded by the thick line (note: the parietal pleura in this area is specifically referred to as the mediastinal pleura). In the hilum of the right lung, the right principal bronchus, right pulmonary artery, right superior pulmonary vein, and right inferior pulmonary vein are located in that order from the cranial side. The pleura between the right inferior pulmonary vein and the diaphragm forms a fold, also referred to as the pulmonary ligament, that anchors the inferior lobe of the right lung to the mediastinum. The azygos vein, after collecting blood from intercostal veins, travels transversely above the right principal bronchus and drains into the superior vena cava. The aortic arch seen curving to the left when viewed from the front is seen curving posteriorly when viewed from this angle. In the superior mediastinum, after serving as a pillow for the superior vena cava, trachea, and esophagus, which are aligned in that order from the anterior side, the aorta travels backward toward the thoracic spine (to the left when viewed from the front), then gradually approaches the thoracic spine, and, after passing through the diaphragm, finds itself almost in front of the thoracic spine. The esophagus is pushed by the interposing descending thoracic aorta and gradually proceeds away from the thoracic spine; it is immediately in front of the descending thoracic aorta at the level of esophageal hiatus

5.2 Part II: Thoracic Manipulation

159 Cranial side

Brachiocephalic a. R brachiocephalic v.

Thoracic duct

Mediastinal pleura L brachiocephalic v. (innominate v.)

I

Ascending aorta Upper thoracic esophagus

II

Sup. vena cava R principal bronchus

R vagus n. Arch of azygos

R pulmonary a. III Ventral side

Dorsal side

R sup. pulmonary v.

IV

R inf. pulmonary v.

Middle thoracic esophagus Thoracic duct

Hilum of R lung

Lower thoracic esophagus Descending thoracic orta

Pulmonary lig.

Inf. vena cava

R hepatic v.

Esophageal opening L vagus n.

R vagus n. Aortic opening

Celiac a.

Caudal side

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

160

R brachiocephakic v.

R subclavian a. L brachiocephalic v. (innominate v.) R recurrent n. R vagus n. R principal bronchus Arch of azygos

Pulmonary br. of R vagus n.

R pulmonary a.

R sup. pulmonary v.

R inf. pulmonary v.

Fig. 5.27  In this second figure in the series, the right lung is retracted anteriorly. This procedure applies a “small twist” to the mediastinum and allows us to see some of the structures in the back side of the hilum of the right lung through the pleura, including the membranous part (posterior wall) of the right principal bronchus and the posterior aspect of the right inferior pulmonary vein (but not the right pulmonary artery or right superior pulmonary vein, which are located more ventrally). This twist means that the membranous part of the lower trachea is also exposed. The azygos vein is extended in length as a result of twist With this “small twist” being applied, retracting the right brachiocephalic vein cranially allows us to identify

the origin of the right recurrent laryngeal nerve, as shown. The right vagus nerve, after entering the mediastinum, branches off the right recurrent laryngeal nerve beyond the right subclavian artery. This nerve turns around the right subclavian artery and then ascends along the right border of the trachea, making itself looking like a reverse J when viewed from the front, but a normal J when viewed from the angle of this figure as it branches and travels backward. After giving off the right recurrent laryngeal nerve, the main trunk of the vagus nerve descends to the right of the trachea, passes under the azygos vein, and then descends along the esophagus. On the way, it also gives off the pulmonary and cardiac branches

5.2 Part II: Thoracic Manipulation

161

R subclavian a. L subclavian a. Thoracic duct

Arch of aorta

Leaf-shaped area (No.106-tbL LN) L venous angle Aortic arch Leaf-shaped area

L pulmonary a.

Lig. arteriosum L recurrent n. Azygos v. (divided) R 3rd intercostal a.

R bronchial a.

Azygos v. (divided) L pulmonary a. R inf. pulmonary v.

L principal bronchus L vagus n.

Pericardium

L inf. pulmonary v. R vagus n.

Fig. 5.28  In this third figure in the series, the tension generated by the azygos vein is released and the parietal (mediastinal) pleura is dissected above and below this vein, which applies a “major twist” to the mediastinum. This exposes structures at the back side of the hilum of the left lung, including the membranous part (posterior wall) of the left principal bronchus and the posterior aspect of the left inferior pulmonary vein. When looking at the trachea, it is also partially exposed, ranging from the membranous part to the left border of the tracheal cartilages Dissecting the azygos vein exposes the hidden right bronchial artery. The right bronchial artery arises from the descending aorta to form a common trunk with the right third intercostal artery, then travels over the esophagus anteriorly, and reaches the right principal bronchus. So, any attempt to further twist the vessel will be hampered at this time by the tension generated by the artery. Retraction of the esophagus posteriorly, taking care not to pull this artery apart, exposes the aortic arch, which has given off the left subclavian artery and entered its descending phase. The left bronchial artery arises directly from the descending aorta and reaches the left principal bronchus. When the leaf-shaped area bordered by the left principal

bronchus and the aortic arch (No. 106-tbL lymph nodes) is burrowed a bit more, the left pulmonary artery and ligamentum arteriosum are encountered Dissecting the No. 106-tbL lymph nodes exposes the origin of the left recurrent laryngeal nerve. The left vagus nerve, after entering the mediastinum, branches off the left recurrent laryngeal nerve in a reverse J shape, or anteriorly, beyond the aortic arch. This nerve then ascends all the way along the left border of the trachea. Extra care should be taken to avoid damaging this nerve during lymph node dissection in this area (No. 106-recL). The main trunk of the left vagus nerve continues to descend along the esophagus while giving off pulmonary and cardiac branches Another important vessel in the mediastinum is the thoracic duct, which ascends along the anterior aspect of the vertebrae and enters the thoracic cavity through the aortic hiatus. After traveling a distance upward parallel to the azygos vein, the duct merges to the left at the level of the fifth thoracic vertebra, passes behind the aortic arch and across the left border of the esophagus, and drains into the left venous angle. So, we should be mindful of the thoracic duct behind the upper thoracic esophagus and be sure to identify the duct correctly to avoid damaging it inadvertently during dissection

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

162 Sup. vena cava R vagus n.

Tracheal cartilage

R phrenic n.

R brachiocephalic v.

R principal bronchus

Esophagus visible beneath

R 3rd intercostal a. Arch of azygos

Azygos v.

Fig. 5.29  We move on now to mediastinal manipulation. Using the left hand, the first assistant retracts the right lung toward the anterior chest wall, which applies a “small twist” to the mediastinum. A moderately large-sized gauze ball can also be used to retract the lung; this is also useful for developing a focus point The first step is to transect the azygos vein. The mediastinal pleura is divided along the upper border of the azygos vein with electrocautery. The vein is isolated with right angle dissection forceps, taking care not to damage

the right bronchial artery, which runs right behind on the cranial side of the azygos arch and located very close to the vein. The tip of the forceps is opened slowly to secure a sufficient margin for transection, followed by ligation and division of the vein. Immediately after transection of the azygos arch, the right bronchial artery is identified and taped without detaching the surrounding supportive tissue. This artery should be preserved as much as possible to maintain blood flow to the trachea

5.2 Part II: Thoracic Manipulation

163

Trachea R vagus n.

R sup. intercostal a.

Azygos (divided)

R bronchial a. No.105 LN

Esophagus

Azygos (divided) Parietal pleura in sup. mediastinum

Fig. 5.30  Dissection should be started from the superior mediastinum. The mediastinal pleura is divided along the esophagus between the stump of the azygos arch and the right subclavian artery. The right vagus nerve, which

descends along the surface of the tracheal cartilage, is seen through the membrane as a cord-like structure as thick as the lead of a colored pencil

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

164

L brachiocephalic v. (innominate v.)

a Brachiocephalic a. R brachiocephalic v.

L common carotid a. R vagus n.

L subclavian a. L recurrent n.

No.105 LN No.106-recL LN R sup. intercostal v. Thoracic duct

R vagus n.

b

Esophageal br. of vagus n.

Trachea

Esophageal plexus

R sup. intercostal a.

3rd intercostal a.

Dissected No.105 LN

Fig. 5.31  This pleural incision causes a “small twist” to the superior mediastinum (a). While the fatty connective tissue containing the upper thoracic paraesophageal lymph nodes (No. 105) is being dissected from caudal to cranial with electrocautery, the esophagus is detached from the membranous part of trachea and the anterior aspect of the vertebrae. Several esophageal branches arise

Vertebra

from the right vagus nerve and merge with esophageal branches from the left vagus nerve and sympathetic nerves to form the esophageal plexus. These branches should be identified and dissected (b). If metastasis to the No. 105 lymph nodes is suspected, remove the right bronchial artery together with the lymph nodes

5.2 Part II: Thoracic Manipulation

165 R vagus n.

a

Inf. cardiac n. R subclavian a.

R subclavian a.

Esophageal br.

No.106-rebR LN No.105 LN

Fig. 5.32  When the right subclavian artery is reached, dissection is continued along the artery from proximal to distal (a). When the vessel tape placed around the right vagus nerve is gently pulled caudally, the right recurrent laryngeal nerve can be identified as it turns around and dives into a deeper layer while winding around the artery. After the fatty connective tissue containing the lymph nodes around the right recurrent laryngeal nerve (No. 106-recR) has been carefully removed, the fatty connective tissue is pulled caudally to further proceed with dissection around the esophagus and removed along with the No. 105 lymph nodes dissected in the previous step. Avoid the use of electrocautery around the recurrent laryngeal nerve and use Cooper scissors instead The anatomy of the right recurrent laryngeal nerve (b). After branching from the right vagus nerve, the right recurrent laryngeal nerve travels along a curved path toward the posterior side of the right subclavian artery and then ascends along the groove between the trachea and esophagus while making contact with the inferior thyroid artery. On the way, the nerve

gives off three to four branches to the esophagus. In this area, keep in mind the anatomy of sympathetic nerves. The cervical sympathetic trunk descends over the anterior surface of the vertebrae and connects to the thoracic sympathetic trunk. The inferior cervical ganglion of the former trunk is usually fused with the first thoracic ganglion, forming a larger ganglion referred to as the stellate ganglion. The inferior cardiac nerve, originating from the stellate ganglion, descends clinging to the posterior surface of the right subclavian artery and enters the cardiac plexus. On the way, it may give off a communicating branch to the recurrent laryngeal nerve, as shown in (b) The No. 106-recR lymph nodes are mostly located behind the recurrent laryngeal nerve. Dissection should proceed while confirming that the esophageal branches of the recurrent laryngeal nerve are distributed to the esophagus and confidently pushing aside these branches with Metzenbaum scissors (some amount of bravery is required though)

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

166

b

Medium cervical ganglion

Inf. thyroid a.

R subclavian artery Ansa subclavia

Thyroid gland R vagus n. Common carotid a.

Inf. cervical ganglion Stellate ganglion

1st thoracic ganglion

Esophageal br. of recurrent laryngeal n.

Fig. 5.32 (continued)

Inf. cardiac n.

Communicating branch R recurrent n.

5.2 Part II: Thoracic Manipulation

167

Pulmonary br. of R vagus n.

R inf. pulmonary v.

Esophagus

No.107 + 109-R LN

Tracheal cartilage

Fig. 5.33  The operative field is diverted to the middle mediastinum to dissect the lymph nodes around the tracheal bifurcation (No. 107) and under the right and left principal bronchi (No. 109). The first assistant retracts the right lung ventrally to apply a “small twist” to the middle

mediastinum so that the posterior aspect of the hilum of the right lung can be viewed from the anterior. Starting around the stump of the azygos arch, the mediastinal pleura is divided along the right principal bronchus

168

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

R inf. pulmonary v.

Pericardium

No.107 + 109-R LN

Fig. 5.34  After identifying the pulmonary branch of the right vagus nerve and the preserved right bronchial artery over the surface of the membranous part (posterior wall) of trachea, the No. 109-R and No. 107 lymph nodes are detached from the bronchial wall, taking care to avoid damaging these branches as much as possible. The left bronchial artery migrates into the top of the No. 107

lymph nodes and should be ligated and divided when deemed necessary. Once the No. 107 lymph nodes have been removed, the pericardium over the left atrium can be seen between the right and left bronchi at their bifurcation. The right vagus nerve should be dissected beyond the origin of its pulmonary branch

5.2 Part II: Thoracic Manipulation

169

Stretched R bronchial a.

No.109-L LN

R vagus n. (cut)

No.107 + 109-R LN

L bronchial a.

Fig. 5.35  The right lung is further retracted ventrally to apply a “major twist” to the middle mediastinum. The paraesophageal tissue is then grasped with a clamp to pull the esophagus dorsally (toward the surgeon). With this manipulation, the posterior aspect of the hilum of the left lung, in particular the membranous part of the left principal bronchus, finally makes its appearance. Being mindful of the left bronchial artery winding around the bronchial wall, the No. 109-L lymph nodes are removed. Dissection of the lymph nodes around the tracheal bifurcation and

those under the right and left bronchi should be started at the caudal portion of the No. 109-R lymph nodes, as described in the previous step, and advanced through the No. 107 up to the caudal portion of the No. 109-L lymph nodes, as if drawing a chevron shape. However, this causes substantial tension to the right bronchial artery, which runs across the front of the esophagus. If the tension of this artery precludes the development of an adequate operative field, we can perform No. 109-L lymph node dissection after esophageal transection (see Fig. 5.45)

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

170

Thoracic duct

L mediastinal pleura

Fig. 5.36  After achieving increased mobility of the upper and middle esophagus, the operative field is reverted to the superior mediastinum to dissect lymph nodes around the left recurrent laryngeal nerve (No. 106-recL). Before doing so, the posterior side of the upper esophagus should be additionally dissected. The pleural detachment from the anterior aspect of the vertebrae was completed in the step described in Fig.  5.31, and now the detachment is further advanced to the left mediastinal pleura. Apart from avoiding rupture of the pleura, we should pay attention to the course of the thoracic duct in this area. After ascend-

ing parallel to the azygos vein over the anterior aspect of the vertebrae, the thoracic duct merges to the left at the level of the fifth thoracic vertebra and travels behind the aortic arch and across the left border of the esophagus. Therefore, the thoracic duct approaches closest to the esophagus in this area. In cases of middle to lower esophageal cancer eligible for intrathoracic anastomosis, it is very unlikely that dissection of this area will be limited by direct tumor invasion into the thoracic duct, so as much as possible of the duct should be preserved

5.2 Part II: Thoracic Manipulation

171

Brachiocephalic a. R brachiocephalic v. L brachiocephalic v (innominate v.).

R vagus n.

No.106-recL LN

L common carotid a.

L subclavian a. Thoracic duct L recurrent n. L mediastinal pleura

Fig. 5.37  Now the upper esophagus is connected to the left border of the trachea just via the connective tissue containing the left recurrent laryngeal nerve and its associated lymph nodes. The operative field is prepared to the left of the trachea by pulling the trachea up with a retracting spatula and pulling the esophagus dorsally toward the surgeon. The left recurrent laryngeal nerve, which ascends

within the connective tissue between the trachea and esophagus, is identified by careful exploration, isolated with a clamp (the clamp should be applied along the esophageal wall to avoid damaging the nerve), and taped with a cotton tape, while ensuring that the preserved thoracic duct is not taped

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

172

Trachea

L recurrent n. Br. of L recurrent laryngeal n. to trachea

R vagus n.

No.108

R bronchial a.

Esophageal br. of L recurrent laryngeal n.

No.106-recL LN

Fig. 5.38  The esophagus is pulled more firmly dorsally with the cotton tape to secure an adequate operative field to the left of the trachea for dissection of the No. 106-recL nodes along the left recurrent laryngeal nerve. This should also be done carefully so as not to pull apart the right bronchial artery traveling across the front of the esophagus. The recurrent laryngeal nerve, after having been liberated to some extent, is taped with a vessel tape and pulled gently to easily detach the lymph nodes. As far as possible, avoid the use of electrocautery because the fatty connective tissue around the nerve contains small

branches of the recurrent laryngeal nerve leading to the esophagus. Left recurrent laryngeal nerve palsy is far more frequent than right recurrent laryngeal nerve palsy and causes breathing difficulty, hoarseness, and postoperative aspiration and associated pneumonia. The surgeon should therefore take time to perform the procedure carefully. Where there is uncertainty about identification of the recurrent laryngeal nerve, the dissection should not be advanced blindly; rather, efforts should be made to identify the nerve that winds around the aortic arch in a recurrent fashion (see Fig. 3.42)

5.2 Part II: Thoracic Manipulation

173

L recurrent n.

Fig. 5.39  Transection of the esophagus: After completing dissection of the No. 106-recL lymph nodes, the transection line of the esophagus is determined, taking into account the location of the lesion and the length of the gastric conduit prepared earlier. The line is usually set around the midpoint of the trachea. A purse-string instrument is applied on the oral side of the transection line, and

a 2-0 nylon suture with straight needles at both ends is passed. The resection side of the esophagus is tied with No. 1 silk suture, and the esophagus is transected along the instrument with Cooper scissors. The cut end of the suture tying the resection side should be kept long enough to be pulled

174 Fig. 5.40 The purse-string instrument is removed, and the esophageal stump is grasped with three pairs of intestinal grasping forceps. Three to four additional interrupted 3-0 silk sutures are placed slightly to the outer side of the existing suture for reinforcement. With the esophageal opening expanded to a triangle shape, the anvil of a 25-mm circular stapler is inserted and the purse-string suture is tied

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer Anvil

5.2 Part II: Thoracic Manipulation

175

L recurrent n.

Resection side of esophageal stump

L subclavian a.

R recurrent n.

No.105 LN No.108 LN

Thoracic duct

Arch of aorta

Fig. 5.41  With the esophagus lifted up with the suture tying the resection-side stump, the fatty connective tissue containing the No. 105 lymph nodes are detached from the anterior aspect of the aorta

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

176

No.106tbL LN

Lig. arteriosum

L recurrent n.

R bronchial a.

L bronchial a.

L vagus n.

Arch of aorta

L pulmonary a.

Fig. 5.42  Once the dissection of the posterior side of the esophagus has advanced beyond the level of the azygos arch, the esophageal stump on the resection side is passed under the right bronchial artery and drawn out to the caudal side of the artery. This expands the leaf-shaped area bordered by the left principal bronchus and the aortic arch, providing a better view of the operative field. While identifying the left recurrent laryngeal nerve as it turns around while winding around the aortic arch, the fatty

connective tissue containing the No. 106-tbL lymph nodes is carefully resected. This should be done cautiously as several left bronchial arteries arising directly from the aortic arch are embedded in this fatty connective tissue. These arteries should be preserved, especially when the right bronchial artery has already been dissected or injured. Encountering the left pulmonary artery and the ligamentum arteriosum indicates the completion of No. 106-tbL lymph node dissection

5.2 Part II: Thoracic Manipulation

a

177

R inf. pulmonary v.

Pulmonary lig.

Central tendon

* * Pericardium

R phrenic n.

b IVC

Mediastinal pleura separated in the preceding dissection rom abdominal cavity

Fig. 5.43  We return now to dissection of the middle mediastinum. The first assistant retracts the inferior lobe of the right lung cranially. Caudal to the right bronchus is the right inferior pulmonary vein, whose lower border is anchored to the diaphragm via a fold-like membrane referred to as the pulmonary ligament, which also corresponds to the transition from the parietal pleura to the visceral pleura. This ligament should be dissected if the inferior lobe obscures the view of the operative field in the

middle and inferior mediastinum (a). This ligament may contain branches of the proper esophageal artery and/or direct branches of the descending aorta (asterisk in (a)), which should be ligated and divided once identified The inferior mediastinal pleura is divided. This pleura is already separated from the esophagus by the preceding dissection procedure from the abdominal cavity and is identified as a membrane through which a dark red structure can be seen deep within (b)

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

178

Pericardium

Proper esophageal a.

No.108

R bronchial a.

L bronchial a. Proper esophageal a. Pulmonary br. of L vagus n. Descending thoracic aorta

Fig. 5.44  Pulling the esophageal stump on the resection side caudally, the fatty connective tissue containing the middle paraesophageal lymph nodes (No. 108) is detached from the aorta and the pericardium. The left vagus nerve is

then dissected distal to the origin of its pulmonary branch. Two to three proper esophageal arteries branching from the descending aorta, identified as solid cords, are ligated and divided when encountered

5.2 Part II: Thoracic Manipulation

R inf. pulmonary v.

179

L atrium

No.109L

No.108 LN

No.110 LN

R mediastinal pleura

L bronchial a.

L mediastinal pleura

No.112ao LN L vagus n. L inf. pulmonary v.

Fig. 5.45  As the dissection is further advanced between the pericardium and the aorta and as the thoracic para-­ aortic lymph nodes (No. 112-ao) are dissected, the left lung is seen through the left mediastinal pleura posteriorly. Any residual No. 109-L lymph nodes attached to the left bronchus should be dissected. As the pericardium is further firmly retracted ventrally and the aorta is retracted dorsally, the posterior aspect of the left inferior pulmonary vein is exposed. The dissection should be advanced

up to the vicinity of the vein. This is the actual scene where we “view the back side of the left mediastinum through right thoracotomy” At this point, the dissection connects with the dissection of the No. 110 lymph nodes from the abdominal cavity and the detachment of the esophagus is completed. Any residual lymph nodes in the inferior mediastinum should be dissected

180 Fig. 5.46  The gastric conduit is slowly drawn into the thoracic cavity ensuring that there is no torsion; the lesser curvature side is the upper side and the greater curvature side is the lower side of the conduit. To avoid damaging the greater omentum, the greater curvature side should be firmly grasped while pulling the conduit, as shown

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

ate

Gre

ure

vat

r r cu

re

atu

er

ss

Le

rv cu

5.2 Part II: Thoracic Manipulation Fig. 5.47  A small incision is made on the anterior gastric wall directly below the esophagogastric junction, and a circular stapler is inserted through the incision. The center rod is advanced through the planned anastomosis site on the greater curvature side and firmly inserted into the anvil shaft placed in the esophageal stump

Fig. 5.48  The cardiac portion of the stomach, which includes the opening for inserting the circular stapler, is transected 3 cm away from the anastomosis with a linear stapler and the resected specimen is removed. Additional interrupted seromuscular 3-0 Vicryl sutures are applied to invaginate the staple line

181

EG junction

3 cm

Opening for circular stapler

182 Fig. 5.49  A nasogastric tube is introduced up to the midpoint of the gastric conduit, then the conduit is pulled back to the abdominal cavity to the extent that there is no slack in the conduit, but no tension applied to the anastomosis. Failure to perform this procedure can cause retention of food in the thoracic gastric conduit and delayed passage through the esophageal hiatus

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

5.2 Part II: Thoracic Manipulation Fig. 5.50 After washing the thoracic cavity, a thoracic drain is placed. With the serratus anterior retracted caudally, the thoracic drain is inserted through the 7th (or 6th) intercostal space (a). A skin incision is then made at a point slightly ventral from the drain insertion point in the same intercostal space, and the drain is tunneled under the serratus anterior and pulled out of the body through the incision (b). Because the lowest point of the thoracic cavity is around the fifth intercostal space in the supine position, the tip of the drain should be placed at the level of the fourth intercostal space

183

a Serratus anterior

VII

VI

V

5

6

7

b

Tip of the drain

184 Fig. 5.51  Three Vicryl 1 sutures are passed through the upper and lower sides of the fourth intercostal space through which the thoracotomy was performed (a). After confirming that there is no damage to the intercostal arteries, the pillow placed under the patient can be removed and the sutures tied to bring the two ribs together. The divided serratus anterior is re-sutured (b)

5  Ivor Lewis Esophagectomy: A Curative Operation for Esophageal Cancer

a

IV

b

V

Serratus anterior

5.2 Part II: Thoracic Manipulation Fig. 5.52  The edge of the latissimus dorsi and the subcutaneous tissue at the same depth are brought together by several interrupted sutures (a). The operation is completed by placing subcutaneous and skin sutures (b)

185

a

Latissimus dorsi

b

Drain placed in L subphrenic space

Thoracic drain

6

Right Hemicolectomy

Abstract

Right hemicolectomy is a typical procedure that reverses the embryonic process by which organs are placed in their final positions. It also provides a valuable opportunity for us to view the top and undersides of the fused mesentery. This chapter describes a procedure of ascending colon cancer resection based on the concept of complete mesocolic excision with central vascular ligation proposed by Professor W. Hohenberger [12]. Standard operation time is 2 h. Keywords

Right hemicolectomy · Lymphadenectomy Fusion fascia of Toldt Fig. 6.1  The surgeon stands on the right side of the patient and makes a pararectal incision starting below the costal arch. It would be actually more accurate to say that right hemicolectomy is an upper abdominal surgery

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_6

187

6  Right Hemicolectomy

188 Fig. 6.2  After careful examination of the abdominal cavity, a wound retractor is placed. With the medial approach, blood vessels are ligated and divided at their root 1 , and then the mesentery is detached from the retroperitoneal space as much as possible. This is followed by detachment from the lateral side of the ascending colon 2 and the transverse colon 3

3

( )

( ) ( )

2

1

6  Right Hemicolectomy Fig. 6.3  The boundary between the retroperitoneum and the visceral peritoneum (Monk’s white line) is identified lateral to the cecum and an incision is made using electrocautery along the line but slightly toward the cecum. The incision is extended along the lower margin of the cecum while keeping about 3 cm away from the ileum until the root of mesostenium is incised. The incision is further advanced toward the imaginary dissection line 10–15 cm proximal from the terminal ileum (a). The ileocecal region may be liberated from the retroperitoneum in some patients. Sagittal cross section shows the positional relationship of the incised peritonea (b)

189

a

Monk's white line

b Horizontal part of duodenum

R colic a. & v.

Ileocolic a. & v.

Root of mesentery of small intestine

Marginal a.

6  Right Hemicolectomy

190

Mid. colic a. & v.

Horizontal part of duodenum

*

Fig. 6.4  After the small intestine is repositioned to the left lower abdominal cavity, the transverse colon is inverted cranially to spread the mesocolon. The anterior aspect of the horizontal part of the duodenum is seen through the mesocolon. The dotted line between the terminal ileum and the ligament of Treitz represents the root of the mesostenium. A peritoneal incision is made starting from the planned dissection line on the ileum, as mentioned in Fig. 6.3, and ascends to the left of the ileocolic

artery up to the front of the superior mesenteric artery (SMA). The incision is advanced along the left margin of the duodenum and then along the middle colic artery and vein on their right side until the transverse colon is reached. This, combined with the procedure described in Fig. 6.3, results in dissection of the top and undersides of the peritoneum between the ileum and the root of the mesostenium (asterisk) and exposure of the intermediate layer (fat plus two layers of the subperitoneal fascia)

6  Right Hemicolectomy

191 Crescent-shaped defect of peritoneum

MCA (L br.)

MCA (R br.)

MCA (root) Acc. rt. colic v. SMV J1

SMA RCA

J2

ICA J3

Root of mesentery (cut)

Fig. 6.5  After completing the peritoneal incision, an incision is made in the avascular part of the intermediate layer of the mesoileum at a certain distance from the intestinal wall. Through the crescent-shaped defect of the peritoneum created by the peritoneal incision, we can identify the middle colic artery (MCA), right colic artery

(RCA), and ileocolic artery (ICA) in that order from the top. We can also see the superior mesenteric vein (SMV) in a slightly deeper layer. Note that the right colic artery and vein are located cranial to the horizontal part of the duodenum, as shown, although these vessels are absent in most cases, as described in Fig. 6.7

6  Right Hemicolectomy

192

SMV

SMA

No.203

Fig. 6.6  The ileocolic artery and vein are dissected at their root. As shown, after the nerve bundle clinging to the artery is dissected with electrocautery and the lymph nodes around the root of the ileocolic artery and vein (No. 203) are dissected as they remain in the resection side, the exposed artery is ligated and divided and then the vein is ligated and divided. Attention must be paid to the course of the ileocolic artery because although it usually crosses the SMV ventrally as shown, it may dive into the dorsal side of the SMV in some cases, with the true root of the ileocolic artery located

behind the SMV, and this requires more careful manipulation The SMV connecting between the ileocolic vein and the gastrocolic trunk of Henle is the most important vessel responsible for venous return in the area extending from the small intestine to the right colon. Damaging this vein, which is also referred to as “surgical trunk,” necessitates complicated repair techniques and can even be life-­ threatening. Although right hemicolectomy itself is not such a complicated procedure, the utmost care should be taken when ligating the surgical trunk

6  Right Hemicolectomy

193

a

Ileocolic v. (root)

Ilecolic a. (root)

No.213 No.203

b

c

¼ of cases

Fig. 6.7  Dissection of the right colic artery and vein at their root and the No. 213 lymph nodes are performed in the same way (a). Again, usually, the right colic artery

¾ of cases

runs on the ventral side and the vein on the dorsal side. However, the artery is present in only about 1 out of 4 patients (b) and so is absent in most cases (c)

6  Right Hemicolectomy

194 Ascending part of duodenum Horizontal part of duodenum

Lig. of Treitz Fusion fascia of Toldt (divided)

No.213

No.203

Fig. 6.8  When the vascular dissection is completed, the mesentery is dissected. Once the cut edge of the peritoneum is everted with forceps, as shown, the loose connective tissue is stretched and the cotton-like mesenteric base

is exposed. Because the fusion fascia of Toldt is inadvertently incised during lymph node dissection around vascular roots, the first layer accessed with electrocautery is usually the layer below the fascia

6  Right Hemicolectomy

195 Mesostenium

Lieocolic a. Fascia of Gerota

No.203

Fusion fascia of Toldt

a Ascending colon

b

SMA Root of mesentery of small intestine IMA

Monk’s white line

L colic a. Fusion fascia of Toldt Subperitoneal fascia

vertebrae

Psoas m. Route a

Fascia transversalis L gonadal a. & v.

L ureter

Route b

RCA

Fusion fascia of Toldt (divided)

No.203 SMV

ICA

When entering into the layer above the fusion fascia of Toldt with no rupture of the fascia

Fig. 6.9  This computed tomography (CT) cross section allows for a detailed explanation of the procedure. Arrow (a) indicates the route of entry into the layer above the fusion fascia of Toldt without rupturing the fascia. Although this route is precise enough for lymph node

When entering into the layer above the fusion fascia of Toldt with rupture of the fascia

d­ issection, the fusion fascia of Toldt will most likely be ruptured during the dissection process. So, it is easier to enter the layer below the fascia, making Route (b) the first choice

6  Right Hemicolectomy

196

a Fusion fascia of Toldt

Subperitoneal fascia Horizontal part of duodenum SMV Gonadal a. & v.

Ureter

Fusion fascia of Toldt

b

Ascending colon SMA

Ureter

Fig. 6.10  The mesentery is dissected toward the lateral side while keeping to Route (b) seen in Fig. 6.9. The presence of the fusion fascia of Toldt over the dissection surface provides reassurance that a cancerous lesion can be completely removed, wrapped in the fascia. Note that the subretroperitoneal fascia is under the dissection surface

Gonadal a. & v.

Subperitoneal fascia

(a). This thin membrane continues from the fascia of Gerota and suspends the ureter and gonadal artery and vein. These structures need to be detached from the membrane with care. The dissection is advanced up to the vicinity of the ureter, at which point a sheet of stretched gauze is placed. CT cross section shows the dissection route (b)

6  Right Hemicolectomy

a

197 Hepatocolic lig.

Monk’s white fine

b

Gauze

Monk’s white line

Fig. 6.11  At this point, the mesenteric dissection is stopped halfway and started over from the lateral side (a). The boundary between the retroperitoneum and the visceral peritoneum (Monk’s white line) is identified lateral to the ascending colon, and an incision is made along the line but slightly toward the colon (b). Layer separation proceeds smoothly when starting the procedure around the right colic flexure. The incision is advanced until it reaches the peritoneal incision made earlier

in the surgery (see Fig. 6.3); it is only a moment before the two incisions are connected because the ascending colon is often shorter than expected (about 15 cm long) Around the right colic flexure, the right extension of the greater omentum may be adherent to the diaphragm (as the left phrenicocolic ligament) or the underside of the liver (as the hepatocolic ligament). If present, these structures should be dissected early with electrocautery

6  Right Hemicolectomy

198

a

Fascia of Gerota seen through fusion fascia of Toldt

Monk’s white line Fusion fascia of Toldt

R ureter

R gonadal a. & v. Psoas m.

b

Horizontal part of duodenum

Ileocoilc a. & v.

Fig. 6.12  The mesentery is dissected while displacing the colon (a). Entering from the intestinal side of the Monk’s white line ensures that the dissection is advanced in the layer above the fusion fascia of Toldt. Area of the dissection (b)

6  Right Hemicolectomy

199

a Fascia on back side of mesocolon

Mesocolon dissected via medial approach

Fusion fascia of Toldt

b

Fusion fascia of Toldt

Fascia on back side of mesocolon Incision Fusion fascia of Toldt

Fig. 6.13  When the dissection advances past the major psoas muscle, the gauze placed earlier (see Fig.  6.10) is seen through the fascia (a). By incising this with electro-

cautery, the mesenteric dissections from both directions are connected and the penetration of the tunnel is achieved (b)

6  Right Hemicolectomy

200

a

Cut end of hepatocolic lig.

Omentocolic lig.

b R branch of mid. colic a. & v.

Acc. rt. colic v.

Horizontal part of duodenum

Fig. 6.14  Next, the part of the right transverse mesocolon colliding with the anteroinferior part of the pancreas and duodenum is released (a). Area of the dissection (b). The right edge of the greater omentum is, in most cases, adherent to the upper portion of the ascending colon (as

the omentocolic ligament). In cases where the cancerous lesion is localized to the lower half of the ascending colon or has not invaded the serosa, allowing preservation of the greater omentum, this adhesion should be dissected with electrocautery before proceeding with the operation

6  Right Hemicolectomy

a

201 Descending part of duodenum

Transverse mesocolon

Acc. R colic v.

Descending part of duodenum

b Fusion fascia

Fusion fascial of Treitz

RCA

ICA *

Subperitoneal fascia (Fascia of Gerota)

Fusion fascia of Toldt Marginal a.

Fig. 6.15  The greater omentum is detached from the right transverse mesocolon (a). This procedure is the reverse of the gastrectomy procedure shown in Fig. 3.12, but it is performed in the same dissection layer. When the middle colic artery is to be preserved, there is no need to advance the dissection across the right border of the

omental bursa. The route for omental dissection (b). Compared with the schematic diagram of Fig.  6.3, the ascending mesocolon is already separated from the abdominal wall (asterisk) and the only remaining procedure is to release the connection with the horizontal part of the duodenum

6  Right Hemicolectomy

202

a Gastrocolic trunk of Henle

Horizontal part of duodenum

Mid. colic a. & v.

R colic a. & v.

Facia of Gerota

Acc. R colic v.

b

Fig. 6.16  The transverse mesocolon is detached from the horizontal part of the duodenum using Cooper scissors (a). Dissection route on a sagittal cross section (b)

6  Right Hemicolectomy

203

a

R br. of mid. colic a. & v.

Acc. R colic v.

Ileocolic a. & v.

R gastropiploic v.

b

PV SMA

Acc.R colic v.

Henle

Transverse colon

Horizontal part of duodenum R br. of mid. colic a. & v.

Fig. 6.17  The accessory right colic vein, which drains into the gastrocolic trunk of Henle, is ligated and divided. The transverse mesocolon widely covers the anterior aspect of the pancreatic uncinate process from the lower side (b), making the base of the mesocolon flabby and considerably thick. The accessory colic vein and the middle

colic vein, which both drain the colon, run over the top and bottom surfaces of the mesocolon, respectively. Now the release of fixation of the right colon by reverse play is completed. Two openings are made with electrocautery on the transverse mesocolon on both sides of the right branch of the middle colic vessels (two dotted ellipses in a)

6  Right Hemicolectomy

204

Duodenal bulbus 1

R br. of mid. colic a. Henle

Root of mid. colic v. Ascending part of duodenum

Acc. R colic v. R colic a. (root) * No.213 Ileocolic a. (root) No.203

2

Fig. 6.18  Again, the mesocolon is widely expanded as described in Fig. 6.5. Any residual adhesion to the duodenum (asterisk) should be dissected. The right branch of

the middle colic vessels (①) and the marginal artery and vein near the planned dissection lines on the colon and ileum (②) are ligated and divided

6  Right Hemicolectomy

a

205

Trimming of colon

Marginal a. (cut)

R br. mid. colic a.(cut)

b

Trimming of ileum

Fig. 6.19  Straight arteries and veins are trimmed around the planned transection lines of the colon (a) and ileum (b). The mesoileum contains multiple loops of marginal arteries and veins and, to compensate for this, more

numerous but shorter straight arteries and veins than in the mesocolon. Moreover, the presence of thicker mesenteric fat near the ileal wall makes trimming of this area more difficult than trimming of the jejunal area

6  Right Hemicolectomy

206 Intestinal clump

Stump clump

Fig. 6.20  An intestinal clamp and a stump clamp are placed slightly apart from each other and the intestine is transected along the Akiyama-type clamp with a pointed blade

Fig. 6.21  Ileotransversostomy is performed with an Albert-Lembert suture. End-to-end anastomosis can be achieved even between stumps of different diameters if the difference is not too great

6  Right Hemicolectomy Fig. 6.22  An easy-to-­ perform alternative is functional end-to-end anastomosis with a linear stapler. After the colon and ileum have been transected with the stapler, small openings are made on the wall of each intestine contralateral to the mesentery. Another linear stapler is placed through the openings and fired to form a V-shaped anastomotic orifice (a). Two stay sutures are placed orthogonally 1 cm away from the staple lines along which the intestines were transected and are pulled in opposite directions. With these two sutures and another stay suture placed at the midpoint, the opening is lifted and closed using a final linear stapler (b), forming an anastomosis with four staple lines slightly apart from each other

207

a

b

1cm

1cm

6  Right Hemicolectomy

208

L br. of mid. colic a. & v.

Horizontal part of duodenum covered by mesentery

R paracolic gutter

Ileal a. & v.

Fig. 6.23  The mesentery is closed with interrupted 3-0 Vicryl sutures. The peritoneal defect in the right lateral abdomen is filled with the anastomosed ileum placed in its natural form. After washing the abdominal cavity, an

8-mm duple drain is placed in the right paracolic gutter and the operation is completed by closing the abdominal wall, suturing in three layers

7

Appendectomy

Abstract

Appendectomy, along with inguinal herniorrhaphy and hemorrhoidectomy, is a surgical procedure commonly performed by young gastrointestinal surgeons. However, appendicitis judged to require surgery in this era of advanced imaging technology tends to be accompanied by a certain amount of inflammation, complicating the surgical procedure. Recently, most cases of appendectomy are performed laparoscopically using a stapler, but this chapter illustrates conventional (open) appendectomy with standard operation time of 30 min. Keywords

Appendectomy · Appendicitis · McBurney’s point

Fig. 7.1  An incision of about 5 cm is made (for adults) that passes a point at the lateral one-third of the line connecting the umbilicus and the anterior superior iliac spine (McBurney’s point) and is along wrinkles in the skin. In patients with a broad and well-developed rectus abdominis muscle, making this incision too close to the midline may result in a transrectal incision, whereas making the incision too laterally may result in entering the retroperitoneum. It is advisable to place the incision about 1 cm laterally and 4 cm medially from McBurney’s point A pararectal incision should be made instead if the skin incision may well need to be extended for ileocecal resection or other reasons

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_7

209

7 Appendectomy

210 Fig. 7.2  The surgeon dissects the subcutaneous tissue and then incises two layers of superficial abdominal fascia using a scalpel and hooked forceps, while the first assistant expands the operative field using two flap retractors. Once the aponeurosis of the external oblique is reached, the first assistant again fully expands the wound in four directions with the retractors

Superficial fascia

Fig. 7.3  A small incision is made with a pointed blade on the aponeurosis of the external oblique muscle along its fibers, and the wound margin is grasped with Pean forceps. The incision is extended vertically (along the fibers) with Mayo scissors. The first assistant applies a retractor to the subaponeurotic layer. In patients with a thick subcutaneous fat layer, the Pean forceps applied to the aponeurosis may be removed if interfering with subsequent procedures

Aponeurosis of ext. oblique m .

7 Appendectomy

211

Fig. 7.4  The exposed internal oblique muscle is torn with the Pean forceps and opened vertically. The first assistant further expands the opening with the retractors

Aponeurosis of ext. oblique m .

Int. oblique m .

Fig. 7.5  The semilunar line (the boundary between the transversus abdominis fibers and the fascia) can now be identified. The muscle fibers lateral to the semilunar line are opened vertically and further expanded with retractors in the same way as described in Fig. 7.4. This way, the peritoneum is finally reached. The first assistant once again makes an effort to expand the wound in four directions with the retractors. Without this effort, the wound gradually becomes smaller compared with the skin incision

Peritoneum

Linea semilunaris

Transversus m.

7 Appendectomy

212 Fig. 7.6 The peritoneum is grasped and lifted with two pairs of hooked forceps and then incised with a round-edged knife. The margin of the incision is grasped with Mikulicz forceps

Peritoneum

Fig. 7.7 The peritoneum is incised vertically with Mayo scissors and the upper and lower margins of the incision are grasped with another two pairs of Mikulicz forceps (four pairs in all). The incision should be kept relatively small because excessively extending the peritoneal incision vertically makes it difficult to suture the incision closed later. Extending the incision beyond the fascia will not contribute to a wider view of the operative field

7 Appendectomy

213

Fig. 7.8  The first assistant applies larger retractors to all layers of the abdominal wall to expand the operative field. If the appendix can be seen directly under the wound, the surgeon withdraws it with long forceps, although having such an operative field would be very lucky

Appendix

Cecum

Fig. 7.9  If the greater omentum covers the operative field, the first assistant pushes the greater omentum and small intestine medially with retractors to expose the cecum or ascending colon. Then, the tenia libera needs to be identified. The point of convergence of the three teniae coli, including the tenia libera, is the root of the appendix

Small intestine

Greater omentum

Teniae coli

214 Fig. 7.10  By tracing the teniae coli proximally with two pairs of long forceps, we reach the appendix. We can do this by repeatedly withdrawing the proximal cecum with the forceps held in the right hand and pushing the distal cecum back into the abdominal cavity with the forceps held in the left hand

7 Appendectomy

Appendix

7 Appendectomy

215

a

Terminal Ileum

Inf. Ileocecal fold

Sup. Ileocecal fold

Appendix

b

Appendicular a. (root) Ilecolic a.

Mesoappendix Appendicular a.

Sup. IIeocecal fold Appendix

Fig. 7.11  Even if the first grasp is on the small bowel, tracing the bowel distally (or so believed) ends up reaching the transition to the cecum and the root of the appendix (a) The mesoappendix, which includes the appendicular artery, passes behind the terminal ileum and is attached by fatty connective tissue in the shape of a right triangle on its anterior surface. This tissue is referred to as the fat triangle,

Inf. IIecocecal fold (bloodless fold)

or more precisely as the inferior ileocecal fold, and it serves as a landmark for identifying the appendix (for this reason it is also referred to as “Merkmal fett”) (b). The inferior ileocecal fold is a membrane of fat that partially hangs down from the mesentery and covers the ileocecal junction

7 Appendectomy

216

Adhesion

Fig. 7.12  It is not unusual for the tip of the appendix to be adherent to the abdominal wall due to severe inflammation and so not being able to be withdrawn immediately. In this case, we can pass a pair of dissection forceps through the mesentery around the root of the appendix to prevent the appendix from falling and then insert an index finger into

the wound to release the adhesions with the fingertip. The adhesions can be released in most cases in this way, although care is needed not to perforate the appendix by detaching it forcibly. If the adhesions cannot be released or the appendix is adherent to the cecum or other structure, we need a retrograde procedure to excise the appendix

7 Appendectomy

217

Appendicular a.

Fig. 7.13  Once the appendix has been withdrawn, it must be grasped firmly enough with forceps to prevent it from falling back into the abdominal cavity. A pair of dissection forceps is passed through the mesentery around the root of the appendix to scoop up the appendicular artery, followed by ligation and division of the artery. When there is severe mesenteric edema, we can do this by scooping the artery; although several attempts might be

needed, we should try to do this in one go by passing the forceps as close to the appendicular wall as possible. Failing to ligate the appendicular artery or, even worse, tearing it may cause the artery to fall into the abdominal cavity and then we have an uncontrollable situation on our hands. The vascular stump should be long enough to allow for reliable ligation. The resection side of the artery can be simply cauterized using electrocautery

218 Fig. 7.14  The appendix is grasped using the forceps held with the left hand, and then a Kocher clamp, held with the right hand, is applied to the appendix several millimeters away from its root to crush that part. It is then displaced several millimeters distally to hold the appendix

7 Appendectomy

Crushed part

Appendicular a. (cut)

Fig. 7.15  The Kocher clamp is then switched to the left hand and a 3-0 Vicryl purse-string suture is made using the right hand. Two points should be noted when making a purse-string suture: (1) making the suture too close to the root of the appendix can make it difficult to create a pocket to embed the stump, and (2) the suture should pass only through the seromuscular layer because a full-thickness suture may result in fecal fistula formation

3-0 Vicryl

7 Appendectomy Fig. 7.16  With the first assistant holding the Kocher clamp, the surgeon ligates the crushed part with a 1-0 Vicryl suture (a). Holding the suture thread with the left hand, the appendix is transected along the proximal side of the Kocher clamp using a pointed blade held with the right hand (b). The stump is disinfected with iodine

219

a

3-0 Vicryl

1-0 Vicryl

b

7 Appendectomy

220 Fig. 7.17  The first assistant holds the suture thread on the appendicular stump and the surgeon grasps the cecal wall (lateral to the purse-string suture) with forceps held in the left hand. The surgeon cuts the suture thread on the stump with Cooper scissors held in the right hand. It is vital that the cecal wall is grasped when cutting the thread; otherwise, the cecum, which is no longer supported by any tissue, will slip back into the abdominal cavity

Fig. 7.18  The forceps are switched to the right hand and one tip of the forceps is inserted into the appendicular stump to grasp it. Then, while the surgeon pushes the stump in, the first assistant tightens the preplaced purse-string suture. After confirming that the stump is fully embedded, the suture thread is cut and the cecum is placed back in the abdominal cavity

3-0 Vicryl

7 Appendectomy Fig. 7.19  With long forceps, several pieces of gauze are inserted toward (1) the pouch of Douglas and (2) the lateral side of the colon to determine the nature of ascites (a). If pus is seen on the gauze, the sites should be wiped completely free of pus by repeating this procedure (b). Washing and drainage may be needed in cases of perforated appendicitis

221

a

2

R paracolic gutter

1 Pouch of Douglas

b

Fig. 7.20 For abdominal closure, the peritoneum is closed using continuous 3-0 Vicryl sutures. With the excess of the same thread, one suture is made through the internal oblique and transversus abdominis muscles together Peritoneum

Int. oblique m. + transversus m.

7 Appendectomy

222

Aponeurosis of ext. oblique m.

Fig. 7.21  The aponeurosis of the external oblique muscle is repaired with about 3 interrupted 1-0 Vicryl sutures. Finally, the skin is sutured closed to complete the operation

8

Anatomy of the Rectum and Surrounding Structures

Abstract

Increased use of total mesorectal excision has led to increased discussion of the detailed fascial anatomy around the rectum. Several review articles that I have to hand give the impression that the pelvis is filled with a tediously large number of fascias. Is the fascial anatomy in the pelvis really that complicated that fascias need to be distinguished by so many different names? Reading these articles more closely and skeptically, it becomes clear that some membranes have multiple names, while other membranes are identified differently by different authors. So, we have a potentially confusing situation here. A key objective in this book is to explain clearly what appears to be complicated. This begins in Chap. 1, on the anatomy of the stomach, by stating that the major principle of the mesentery applies not only to the rectum. And here, in the present chapter, this is continued by illustrating the anatomy of the rectum and surrounding structures based on the knowledge that the fascia of Gerota continues to the subretroperitoneal fascia and the fascia propria of the rectum continues to the prehypogastric nerve fascia and then to the rectosacral fascia, and that these two fascial systems are fused around the lower rectum to become the fascia propria of the rectum in a broad sense and circumferentially surround the rectum. Moreover, we view the fascia of Denonvillier as a connective tissue with the same structure as the fusion

fascia of Toldt, comprising a fused folded peritoneum. Also, we look at the “presacral fascia” (this eventually merges with the aforementioned systems) and another system consisting of the “fascia transversalis.” Ultimately, we find that we can clearly explain the anatomy of the rectum and surrounding structures without using other names while at the same time ensuring consistency with the anatomy of the stomach (Chaps. 1 and 2) and the inguinal canal (Chap. 19) and surrounding structures. In this chapter, Sects. 8.1–8.8 describe the anatomy of the pelvic floor muscles, arteries, and nerves, and Sects. 8.9–8.16 focus on clarifying the fascial anatomy.

Keywords

Rectum · Mesentery · Total mesorectal excision · Pelvic fascial anatomy · Retrorectal space

8.1

Pelvis and Ligaments (Fig. 8.1)

① Sacrotuberous ligament: Connects the ischial tuberosity to the posterior superior/inferior iliac spines, the sacrum, and the lateral margin of the coccyx.

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_8

223

8  Anatomy of the Rectum and Surrounding Structures

224

Greater sciatic foramen

Muscular lacuna Inguinal lig. Vascular lacuna

Sacrospinous lig. Sacrotuberous lig.

Obturator canal

Lesser sciatic foramen

Obturator membrane

Fig. 8.1  Pelvis and ligaments

② Sacrospinous ligament: Connects the ischial spine to the lower sacrum and the lateral margin of the coccyx. ③ Greater sciatic foramen: A foramen partitioned by the sacrospinous ligament and further divided into the following two compartments by the piriformis muscle that passes through it: ③-1 Suprapiriform foramen: Allows for passage of the superior gluteal artery. ③-2 Infrapiriform foramen: Allows for passage of the internal pudendal artery, pudendal nerve, and sciatic nerve. ④ Lesser sciatic foramen: A foramen bordered by the sacrotuberous and sacrospinous ligaments allowing for passage of the internal obturator muscle. The internal pudendal artery and the pudendal nerve, after passing through the infrapiriform foramen out of the pelvis, also pass through this foramen into the ischiorectal fossa (beneath the levator ani muscle).

⑤ Inguinal ligament: A ligament extending from the anterior superior iliac spine and the pubic tubercle. The space bordered by this ligament and the superior pubic ramus is divided by the iliopectineal arch into the following two compartments: ⑤-1 Vascular lacuna: Allows for passage of the femoral artery and vein. ⑤-2 Muscular lacuna: Allows for passage of the iliopsoas muscle and the femoral nerve.

8.2

I liopsoas, Internal Obturator, and Piriformis Muscles (Fig. 8.2)

① Iliopsoas muscle: Composed of the iliac muscle, the psoas major muscle, and the psoas minor muscle. The iliac muscle originates from the entire surface of the iliac fossa on the inner aspect

8.3 Structure of the Pelvic Floor: Part I

225

Psoas m.

Iliacus m. Suprapiriform foramen

Piriformis m.

Infrapiriform foramen Iliopsoas m. Obturator intermus m.

Fig. 8.2  Iliopsoas, internal obturator, and piriformis muscles

of the ilium, while the psoas major muscle originates from the lumbar vertebral bodies and transverse processes. After merging, these muscles pass through the muscular lacuna under the inguinal ligament out of the pelvis and attach to the lesser trochanter of the femur. ② Internal obturator muscle: Originates from the obturator membrane and the surrounding area on the inner side of the pelvis, turns in a right angle on the edge of the lesser sciatic foramen as a pulley, passes through the lesser sciatic foramen out of the pelvis, and attaches to the trochanteric fossa of the femur. ③ Piriformis muscle: Originates from the anterior surface of the sacrum between the second and fourth sacral foramina, passes through the greater sciatic foramen out of the pelvis, and attaches to the greater trochanter of the femur.

8.3

 tructure of the Pelvic Floor: S Part I (Fig. 8.3)

The pelvic floor consists of two layers: the upper layer formed by the levator ani muscle and the lower layer formed by the urogenital diaphragm. The levator ani muscle is a pair of bilateral muscle bundles that originate from the pubis and the tendinous arch of the levator ani muscle (thickening of the internal obturator fascia that connects the pubis and the ischial spine) and merge in the midline to form a reverse dome. Formed during this process are the urogenital hiatus and the anal hiatus, which allow for passage of the urethra (and the vagina in women) and the rectum, respectively. Between the anal hiatus and the coccyx is a thick

8  Anatomy of the Rectum and Surrounding Structures

226

Anococcygeal body

Rectum Tendinous arch of levatorani m. Urogenital hiatus Perineal body

Anal hiatus Vas deferens

Ureter

Bladder

Seminal vesicle

Prostate

Corpus spongiosum Corpus cavemosum

Fig. 8.3  Structure of the pelvic floor: Part I

8.4 Structure of the Pelvic Floor: Part II

l­igament referred to as the “anococcygeal body,” which provides the tendon of insertion for the levator ani muscle bundle. This serves as a beam that supports the pelvic floor along with the perineal body, as discussed in the following section.

8.4

 tructure of the Pelvic Floor: S Part II (Fig. 8.4)

Let us look at the anatomy of the pelvic floor more closely. Between the urogenital hiatus and the anal hiatus, or at the apex of the reverse dome, is a lump of fibrous connective tissue as big as the tip of the thumb (basically a hard lump) that is referred to as the perineal tendon center or “perineal body.” This is literally “the center of the perineum” that supports the many parts that constitute the pelvic floor from below. The levator ani muscle consists of three parts: ① puborectalis, ② iliococcygeus, and ③ pubococcygeus muscles. The puborectalis muscle (①) originates from the pubis, passes through the perineal body, and then turns around the rectum to form a loop while lifting it up anteriorly. The iliococcygeus muscle (②), which constitutes the major part of the levator ani muscle, originates from the tendinous arch of the levator ani muscle and, while in contact with the lateral aspect of the puborectalis muscle (①), inserts to the coccyx and the anococcygeal body. The reverse Y-shaped pubococcygeus muscle (③), which is located most

227

superficially when viewed from the abdominal cavity, extends from the pubis over the puborectalis (①) and iliococcygeus (②) muscles to the coccyx. The external anal sphincter is located below and in contact with the levator ani muscle and surrounds the anal canal in a circular manner. It can be divided into the deep (I), superficial (II), and subcutaneous (III) parts. The deep part (I) is ring-shaped and is fused with the puborectalis muscle fibers. The superficial part (II) is an anteroposteriorly elongated spindle shape and attaches to the perineal body anteriorly and to the anococcygeal raphe posteriorly. The subcutaneous part (III) is located subcutaneously along the anal verge and slightly apart from the deep (I) and superficial (II) parts. It is also separated from the internal anal sphincter (thickened inner circular muscle) by the conjoined longitudinal muscle fibers continuing from the outer longitudinal muscle of the rectum (Fig. 8.6b). The anterior half of the pelvic floor is reinforced from below by the urogenital diaphragm composed mainly of the deep transverse perineal muscle. The superficial transverse perineal muscle, located along the posterior margin of the diaphragm, serves as a suspender to suspend the perineal body from the ischial tuberosity. The superior and inferior aspects of the perineal body are attached by the fascia of Denonvilliers, which will be described in Fig. 8.11, and by the bulbospongiosus muscle, which supports the penis, respectively. This is why this structure is called the perineal tendon “center.”

8  Anatomy of the Rectum and Surrounding Structures

228

a Puborectalis Levator ani

Iliococcygeus

F De ascia non of villi ers

Pubococcygeus

Coccyx

rch

sa ou din m. n te or To levat of

Anococcygeal body To pubis

To

To

in

f.

Anococcygeal raphe

Perineal body

isc

pu

hia

bi

c

l tu

ra

ber

I Deep II Superficial III Subcutaneous

osi

ty

m

us

Ext. anal sphincter

To perineal body Urethra Superf. transverse perineal m. Bulbospongiosus m.

b

Urogenital diaphragm

Deep transverse perineal m.

Levator ani

Deep transverse perineal m.

Anococcygeal raphe I

Bulbospongiosus m.

Perineal body

Superficial transverse perineal m.

Fig. 8.4  Structure of the pelvic floor: Part II

II III

Ext. anal sphincter

8.6 Internal Pudendal Artery and Its Branches

8.5

I nternal Iliac Artery and Its Branches (Fig. 8.5)

① Superior gluteal artery: Passes through the suprapiriform foramen out of the pelvis and supplies the gluteal region. ② Superior vesical artery: Supplies the upper urinary bladder after branching off from the ­lateral umbilical ligament. The lateral umbilical ligament is a remnant of the umbilical artery, which returns blood from the fetus to the placenta during fetal life, and, just like the round ligament of the liver formed from the umbilical vein, is a cord-like structure with a collapsed lumen. Along the ligament is a cord-like bulge of the peritoneum referred to as the medial umbilical fold (see Fig. 19.6 in Chap. 19 on the anatomy of the inguinal canal and surrounding structures).

229

③ Obturator artery: Passes through the obturator canal out of the pelvis and supplies the adductor muscles. ④ Internal pudendal artery: See Sect. 8.6. ⑤ Middle rectal artery ⑥ Inferior vesical artery

8.6

I nternal Pudendal Artery and Its Branches

The internal pudendal artery passes through the infrapiriform foramen out of the pelvis, turns around the ischial spine, and travels through the lesser sciatic foramen into the ischiorectal fossa (beneath the levator ani muscle). The inferior rectal artery is a branch of this artery.

Int. iliac a.

Ext. iliac a. Obturator a.

Inf. epigastric a.

Sup. vesical a.

Sup. gluteal a.

Int. pudendal a.

Mid. rectal a.

Lateral umbilical lig.

Inf. vesical a.

Fig. 8.5  Internal Iliac artery and its branches

8  Anatomy of the Rectum and Surrounding Structures

230

a

Infrapiriform foramen Sacrospinous lig.

Lesser sciatic foramen

Levator ani

Sacrotuberous lig. Outer longitudinal m.

Inf. rectal a.

Inner circular m.

b

Pudendal canal (Canal of Alcock) Int. pudendal a. Pudendal n. Int. pudendal v. Puborectalis m.

Ext. anal sphincter

I Deep II Superficial

Int. anal sphincter

III Subcutaneous Conjoined longitudinal muscle fibers

Fig. 8.6  Internal pudendal artery and its branches

8.8 Anatomy of the Nervous System (Autonomic Nervous System)

Figure 8.6b shows a schematic diagram of the ischiorectal fossa on frontal cross section of the pelvis. The internal pudendal artery, along with the internal pudendal vein and the pudendal nerve, runs through the fascial canal formed along the lateral wall of the ischiorectal fossa. This canal is referred to as the pudendal canal or canal of Alcock. This figure also clearly shows the positional relationship between the internal and external anal sphincters. The internal anal sphincter is a thickening of the inner circular muscle of the rectum at the terminal portion. The outer l­ ongitudinal muscle becomes the conjoined longitudinal muscle fibers and enters the space between the internal and external anal sphincters.

8.7

Anatomy of the Nervous System (Somatic Nervous System) (Fig. 8.7)

Lumbar Plexus  Formed by the anterior branches of the L1–L5 spinal nerves and gives two major branches, the femoral and obturator nerves. • Femoral nerve (L1–L4): Descends between the femoral and iliac muscles and passes along with the iliopsoas muscle through the muscular hiatus out of the pelvis. It then innervates the iliopsoas muscle inside the pelvis and the femoral muscles outside the pelvis. • Obturator nerve (L2–L4): Descends along the medial border of the psoas major muscle and passes along with the obturator artery through the obturator canal out of the pelvis. It then innervates the adductor muscles. Sacral Plexus  Formed by the anterior branches of the L5–S3 spinal nerves. The largest branch is the sciatic nerve, which passes through the infrapiriform foramen out of the pelvis and innervates the internal obturator and piriformis muscles inside the pelvis and the lower thigh muscles outside the pelvis. Pudendal plexus  Formed by the anterior branches of the S2–S4 spinal nerves. The pudendal nerve,

231

the largest branch, runs parallel to the internal pudendal artery and innervates the external anal sphincter, urethral sphincter, and ischiocavernosus and bulbocavernosus muscles, among others.

8.8

Anatomy of the Nervous System (Autonomic Nervous System) (Fig. 8.8)

Sympathetic Nervous System The nerve fibers extending anteriorly from the lumbar plexus of the bilateral sympathetic nerve trunks (lumbar splanchnic nerves) gather in front of the aorta and are vertically connected with each other to form the aortic plexus (①). These plexuses are especially well developed at sites where the abdominal aorta gives off branches, referred to as the celiac, superior mesenteric, and inferior mesenteric plexuses, respectively. Among these, the nerve bundle forming the inferior mesenteric plexus (②) courses along the inferior mesenteric artery (IMA) inside the mesocolon toward the sigmoid colon and the rectosigmoid (Rs). The aortic plexus (①), after passing through the aortic bifurcation, merges with the nerve fibers extending from the L2 and L3 lumbar splanchnic nerves in a triangular area bounded by the bilateral common iliac arteries and the promontorium (iliac triangle), forming the superior hypogastric plexus (③). The nerve bundle then divides into the right and left hypogastric nerves (④), which, while giving direct branches to the upper rectum (Ra), descend along the anterior surface of the sacrum medial to the internal iliac artery and eventually merge with the pelvic plexus (⑥) (i.e., the inferior hypogastric plexus). The lower part of the sympathetic nerve trunk descends medial to the anterior sacral foramen. This sacral plexus also gives off small branches (sacral splanchnic nerves) to the pelvic plexus. Parasympathetic Nervous System The pelvic splanchnic nerves (⑤) arise as the innermost anterior branches of the S2–S5 sacral nerves and enters the pelvic plexus.

8  Anatomy of the Rectum and Surrounding Structures

232

L1 Lumbar plexus

L2 L3

Femoral n.

Sacral plexus L5

S1

S2 S3

Obturator n.

S4

Pudendal plexus

Pudendal n.

Sciatic n.

Fig. 8.7  Anatomy of the nervous system (somatic nervous system)

8.8 Anatomy of the Nervous System (Autonomic Nervous System)

233

Sup. mesenteric plexus

Aortic plexus

Inf. mesenteric plexus

Lumbar splanchnic n. Sigmoid a.

Sympathetic trunk

Sup. rectal a.

Sup. hypogastric plexus

Hypogastric n. (R) (sympathetic) Sacral splanchnic n. (sympathetic)

Lateral lig.

Pelvic splanchnic n. (parasympathetic)

Pelvic plexus (sympathetic + parasympathetic) NVB Corpus cavernosum

Fig. 8.8  Anatomy of the nervous system (autonomic nervous system)

Pelvic Plexus The pelvic plexus (⑥) is a flat-shaped plexus formed from a combination of the hypogastric nerve (④) (plus the sacral splanchnic nerve), a sympathetic nerve, and the pelvic splanchnic nerve (⑤), a parasympathetic nerve. Damaging the hypogastric nerve causes ejaculatory dysfunction, while damaging the pelvic splanchnic nerve causes erectile dysfunction and impaired contraction of the urinary bladder and rectum, in short, bladder and bowel dysfunction.

Sensory nerve stimulation via stretch receptors elicited by distension of the bladder wall is also transmitted through the pelvic splanchnic nerves to the S2–S5 sacral ganglia, so damaging the pelvic plexus can cause complex disorders of urination, defecation, and sexual function. From the pelvic plexus, visceral branches extend anteriorly to the bladder and prostate gland, intermediately to the uterus, and laterally to the rectum. These branches course along the

234

blood vessels branching from the internal iliac artery. The nerve fiber leading to the rectum is referred to as the “lateral ligament” and contains the middle rectal artery, which is in most cases small enough to be cauterized. The nerve fiber leading to the prostate gland is referred to as the “neurovascular bundle” (NVB). The NVB courses lateral to the prostate gland and, after giving off a branch to the prostate gland, reaches the spongy body of the penis where it controls erection. Even with efforts made to preserve the pelvic plexus, damaging any of the vesical branches or NVB results in loss of urination and erectile function.

8  Anatomy of the Rectum and Surrounding Structures

the subperitoneal fascia, which is a “sheet of thickened loose connective tissue.” Of these, the inner fascia (i.e., the fascia on the retroperitoneal side) is specifically referred to as the “subretroperitoneal fascia.” This is a broad fascia uninterruptedly lining the whole peritoneum and is locally referred to as the anterior layer of the renal fascia, also known as fascia of Gerota. The outer fascia (i.e., the fascia on the body surface side) is also a broad fascia and is specifically referred to as the “presacral fascia” in the posterior wall of the pelvis (it is discussed again in Fig. 8.12 on the end point of pre- and retrorectal dissection). The outer surface of the presacral fascia makes contact with the fascia transversalis, again set apart by a small layer 8.9 Structure of the Retrorectal containing loose connective tissue. Outside the fascia transversalis are abdominal muscles or Space: Part I bone. Let us now explore the fascial anatomy, the main Let us look now at Fig. 8.9c. The RS, continusubject of this chapter. Computer tomographic ing from the sigmoid colon, also has its mesen(CT) cross sections of the descending colon (D), tery, but differs from other parts of the colon sigmoid colon (S), and rectosigmoid (RS) are because it is attached by a considerably wider shown in Fig. 8.9a, b, and c, respectively. base of the mesentery. This means that a sparse The mesentery is a fat fold that anchors the space is formed between the rectum and the intestine to the abdominal wall and has a double-­ sacrum. This is the “retrorectal space.” The forlayered structure in which the peritoneum and mation of the retrorectal space is closely related the subperitoneal fascia surround its surface to the “division of the aorta into the right and left from both sides in an omega shape. The descend- iliac arteries” during the developmental process. ing mesocolon merges with the abdominal wall While other mesenteries arise from the aorta as a after colliding with the posterior wall, while double-layered peritoneal membrane like a partiapposed peritoneal membranes are fused to tion, the mesorectum, which arises from the become the fusion fascia of Toldt (Fig.  8.9a). divided aorta, has its base separated into right Because the fusion fascia of Toldt ends near the and left. Also, the superior rectal artery (SRA), external iliac artery, the sigmoid colon remains the main supplying vessel of the rectum, is not unanchored and regains its own mesentery, happy accompanying the iliac artery and immewhich, however, remains morphologically diately diverges from the aorta and then comes incomplete due to partial physiological adhe- close to the rectum while descending along the sion of adjoining peritoneal membranes midline. This results in reduced fat density of the (Fig. 8.9b). mesorectal base, and a “space” is formed that Below the fusion fascia of Toldt and the ret- contains loose connective tissue. This is how the roperitoneum physiologically adhered to the retrorectal space is formed. The hypogastric sigmoid mesocolon is the extraperitoneal fat, set nerve left behind by the SRA has no choice but apart by a small layer containing loose connec- to split into two, descending medial to the iliac tive tissue. This fat layer provides paths for the artery while giving off several small branches to gonadal artery and vein, ureter, plexuses, and the rectum and finally forming the lateral ligaperiaortic lymph nodes. The inner and outer sur- ment with the middle rectal artery branching faces of the extraperitoneal fat are covered by from the internal iliac artery before reaching the

8.9 Structure of the Retrorectal Space: Part I

a (D)

235

L

R

IMA

LCA

Fusion fascia of Toldt Marginal a. Peritoneum

Inf. mesentericplexus

Fascia transversalis Ao

IVC

Fascia of Gerota

Subperitonial fascia

Extraperitonealfat Muscle

b (S)

Upper border of retrorectal space

Sigmoid a.

Sup. hypogastric plexus Physiological adhesion of sigmoid mesocolon

R common iliac a. Gonadal a. & v. IVC

Ureter

Med. sacral a.

L common iliac a.

c (RS) Rectal branches of hypogastric n. SRA Retrorectalspace

L hypogastric n.

R hypogastric n.

L common iliac a. L common iliac v. Pre-sacral fascia Med. sacral a.

Fig. 8.9  Structure of the retrorectal space: Part I

8  Anatomy of the Rectum and Surrounding Structures

236 IMA

Sup. hypogastric plexus

Rectum SRA

R hypogastric n. Upper border of retrorectal space

Iliac triangle

R common iliac a. L common iliac a.

Retrorectal space (loose connective tissue) Med. sacral a.

L hypogastric n.

Fig. 8.9 (continued)

rectum. On the dorsal side of the retrorectal space is an artery descending straight from the bifurcation of the right and left iliac arteries, namely, the median sacral artery. The upper border of the retrorectal space appears to be located around the iliac triangle where the division of the aorta occurs, but it cannot be clearly defined because the space is essentially a loose connective tissue (the space itself can be found more cranially around the root of the IMA where the SRA diverges from the aorta and gradually expands distally). To be honest, there is not actually a space in the body that can be referred to as the retrorectal “space.” This is an artificially formed space created by the entrance of air (which can be CO2 in the case of laparoscopic surgery) when the surgeon lifts the RS and incises the peritoneum; it is morphologically distinct from the omental bursa or the infracardiac bursa (see Fig. 5.12), both of which are lined with the serous membrane and maintain a “cavity” structure. Figure 8.9c shows the three-dimensionally constructed upper border of the retrorectal space

in the iliac triangle. The SRA arises considerably cranial to the bifurcation of the iliac arteries and descends along the ridge of the retrorectal space inside the fat tissue behind the rectum. The hypogastric nerve divides into right and left at a level lower than the bifurcation of the iliac arteries and descends medial to the internal iliac artery toward the pelvic plexus. The upper border of the retrorectal space is located around this division point, that is, around the superior hypogastric plexus. The hypogastric nerve courses very close to the retrorectal space. When entering the retrorectal space during surgery, the surgeon must always identify this nerve to avoid damaging it.

8.10 Structure of the Retrorectal Space: Part II Now let us look at the Ra. Rather than the “look­up” view shown in Fig. 8.9a–c, Fig. 8.10a shows the “look-down” view, the same view that the surgeon has, of a cross section at the level of the

8.10 Structure of the Retrorectal Space: Part II

a

237

L

R

(Ra, look-down view) Lateral umbilical ligament (medial umbilical fold) Inf. epigastric a (lateral umbilical fold)

Fascia transversalis

Bladder Vas deferens

Retroperitoneum

Iliacusm. Gonadal a. & v.

Subperitoneal fascia

SRA

Ext. iliac a. & v.

Fascia propria of rectum

Psoas m.

R

Pre-hypogastric n. fascia

Ureter Int. iliac a. & v.

Pre-sacral fascia

Rectal branch Hypogastric n. Retrorectal space

Med. sacral a.

b (Ra, cross-section)

L5

L4

S1 2 3

Supralevator space 5

4

Rectosacral fascia

Fig. 8.10  Structure of the retrorectal space: Part II

Retrorectal space

238

straight line shown in Fig. 8.10b. The spider web-­ like loose connective tissue covering the retrorectal space is gradually densified and replaced by the surrounding fat tissue (illustrated as a gradually darkened margin of the retrorectal space in Fig.  8.10a). This thickened zone is also termed “fascia.” The spider web threads, which are cut as if melted when the retrorectal space is entered, merge with this fascia. When viewed from the inside of the retrorectal space (point R in Fig. 8.10a), the fascia lining the space is folded back along the right and left hypogastric nerves. This means that small nerve fibers extending from the hypogastric nerve to the rectum are forced to pass between the two fascias arising from both the abdominal cavity and sides of the retrorectal space forming the shape of the Chinese character “八.” Considering this as part of the basic mesenteric structure, it would be more natural to say that the mesorectum “divides into two parts from its base,” rather than that it “disappears” around the Ra. The fascia lining the retrorectal space is thickest on the rectal side (the anterior wall when viewed from point R) and is accompanied by a thick fat layer between the retrorectal space and the rectum (including the SRA). This part of the fascia is referred to as the “fascia propria of the rectum.” The fascia lining the sacral side (posterior wall) of the retrorectal space appears to be identical to what is called the “parietal pelvic fascia” by Professor RJ Heald, who first described total mesorectal excision (TME) [13] and who named the fascia propria of the rectum the “visceral pelvic fascia.” In this book, we use the term “prehypogastric nerve fascia” [14] with the intention of warning surgeons to do the following: enter the retrorectal space while ensuring that the fascia anterior to the hypogastric nerve remains on the sacral side so as to spare the nerves. Around the lower rectum (Rb), the fascia propria of the rectum extends toward the pelvic floor while lining the dorsal surface of a thick nerve bundle branching at a sharp angle from the pelvic

8  Anatomy of the Rectum and Surrounding Structures

plexus, that is, the lateral ligament. Because this nerve bundle also allows for passage of the middle rectal artery (a branch of the internal iliac artery), the lateral ligament can be considered the last vessel group to be included in the bilaterally split mesorectal base. Although in general the fascia propria of the rectum refers to the fascia surrounding the fat tissue on the dorsal side of the rectum, we should remember that this is the posterior layer and that the fascia continuing from the subretroperitoneal fascia and covering the anterior side of the rectum is the anterior layer. These two layers, which are interrupted by the right and left leaves of the mesorectum, merge beyond the lateral ligament where the mesorectal base discontinues, surrounding the Rb circumferentially (as illustrated in Fig. 8.15). The rectum, which was once lifted from the body wall by the retrorectal space, again approaches the sacrum around S4, around which loose connective tissue again becomes denser. This loose connective tissue is recognized as a robust membranous structure forming a tent between the fascia propria of the rectum and the prehypogastric nerve fascia during surgery. This structure, which also serves as a suspender and anchors the lower rectum to the sacrum, is referred to as the “retrosacral fascia.” This used to be called “fascia of Waldeyer,” but this is not an appropriate name because the fascia that Waldeyer described appears to be part of the prehypogastric nerve fascia. Although some say that there is no rectosacral fascia, when we consider that the loose connective tissue on the posterior side of the rectum indeed becomes denser around S4 and that the “fascia” is essentially thickened connective tissue, it is more convenient to distinguish this fascia as the rectosacral fascia so that it can be used as a landmark for posterior dissection. This rectosacral fascia is generally recognized as the lower border of the retrorectal space; however, beyond the border continues a space containing loose connective tissue referred to as the “supralevator space” for a certain distance.

8.13 Lateral Ligament

8.11 Structure of the Prerectal Space Let us take a look now at the anatomy of the prerectal space. During fetal life, there is a recess (the pouch of Douglas) between the rectum and the urogenital organs (seminal vesicle, prostate gland, and vagina) that is connected to the perineal body. As organs grow, the tip of the recess is pulled by the perineal body and then the peritoneum, accompanied by the subperitoneal fascia, fits into the recess. This forms a deep trough in that area. The apposed peritoneal membranes are then fused, and the lower end of the pouch of Douglas is closed. During this process, superficial epithelial cells are lyzed and fused with connective tissue to form “the fascia of Denonvilliers,” a structure consisting of essentially the same components as the fusion fascia of Toldt. The layer between the peritoneum and the subperitoneal fascia containing loose connective tissue forms a space as a result of the subperitoneal fascia folding back. Although the fascia of Denonvilliers, which descends like a thick curtain, partitions this space into the “prerectal space” on the rectal side and the “retroprostate space” on the prostate side, clinically both layers can be collectively recognized as the “prerectal space.” Another similarity of this fascia to the fusion fascia of Toldt is that the spaces both above and below the fascia can be entered.

8.12 E  nd Point of Pre- and Retro-­ Rectal Dissection The fascial anatomy described in Figs. 8.9, 8.10, and 8.11 is illustrated in a sagittal cross section. The upper and lower borders of the retrorectal space are formed by the iliac triangle and the rectosacral fascia, respectively. The prehypogastric nerve fascia forming the posterior wall of the retrorectal space fuses with the presacral fascia,

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which has descended along the sacrum, beyond the rectosacral fascia after reaching the coccyx, forming a single layer (∗). This fascia expands while covering the levator ani muscle and its tendon of insertion, the anococcygeal body (described in Figs.  8.3 and 8.4), and finally adheres to the rectum and merges with the fascia propria of the rectum. This turnaround point is the lower end of the supralevator space and the end point of retrorectal dissection. Now let us look at the prerectal space. The objective of TME can be achieved only by prerectal dissection, but if that were true, the space either above or below the fascia of Denonvilliers could be entered. However, during actual surgery, it is more natural to enter above the fascia for ease of dissection and proceed with the fascia of Denonvilliers remaining attached on the rectal side. This will expose the seminal vesicle, which is covered only by the thin retroperitoneal fascia. Beyond the seminal vesicle, nerve fibers extending from the NVB enter between the fascia of Denonvilliers and the posterior surface of the prostate gland, making the retroprostate space narrower. So, the fascia of Denonvilliers needs to be dissected once so that the dissection layer can be switched to the prerectal space (route indicated by the arrow). This route also ends where the lower end of the fascia of Denonvilliers is connected to the perineal body. This is the end point of prerectal dissection.

8.13 Lateral Ligament Figure 8.13 shows the look-down view of the cross section through line AB from Fig. 8.12. The plane at this level passes through the fascia of Denonvilliers, the lateral ligament, and the rectosacral fascia. The fascia, after turning around along the hypogastric nerve in a “八” shape, surrounds the lateral ligament, which was driven into the rectum like a wedge, to complete its role as a mesenteric base. From this angle, it is clear

8  Anatomy of the Rectum and Surrounding Structures

240

a

Pubis

Recess Rectum

Perineal body

b

Bladder

Seminal vesicle Prostate

c

Retroprostate space

Prerectal space

Fascia of Denonvilliers

Fig. 8.11  Structure of the prerectal space

8.13 Lateral Ligament

Lateral umbilical lig. Fascia of Denonvilliers

241

Mid. rectal a.

Fascia propria of rectum Upper border of retrorectal space SRA Sup. vesical a.

Pelvic plexus

A

sp

ac

e

Pre-sacral fascia

Re t

ro

re

ct

al

Fascia transversalis

Perineal body Sup. hypogastric plexus Med. sacral a.

NVB

Hypogastric n.

B Pre-hypogastric

Inf. vesical a. Anococcygeal body

nerve fascia Rectosacral fascia

Supralevator space Pelvic splanchnic n. Fusion of pre-hypogastric nerve fascia and pre-sacral fascia, forming a single layer (*) Int. pudendal a.

Fig. 8.12  End point of pre- and retro-rectal dissection

Obturator a.

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242

R

L Lateral umbilical lig.

Prostate gland (base)

NVB Inf. vesicala.

Seminal vesicle

is

b Pu

Femoral n.

Vas deferens

V A N

Int. obturatorm. Sup. vesical

Fascia of Denonvilliers

Obturator a. & n.

R lateral lig.

Pelvic plexus

SRA

Fascia propria of rectum

Mid. rectal a. Pre-hypogastric n. fascia

Int. pudendal a. L laterallig. Sciatic n.

Pre-sacral fascia

Pelvicsplanchnic n. Hypogastric n.

Fascia transversalis Rectosacral fascia Med. sacral a.

Piriformism.

Fig. 8.13  Lateral ligament

that the dorsal and ventral sides of the lateral ligament are lined by the turned-around fascia in the retrorectal and prerectal spaces, respectively. The spaces can be seen as the “inner moat” that surrounds the rectum, with the lateral ligament as a “dirt bridge” that connects the pelvic wall and the inner side of the moat (rectum). Beyond the lateral ligament, the rectum is no longer attached by the mesorectal base and is circumferentially surrounded by the fascia propria of the rectum (Fig. 8.15).

8.14 Three-Dimensional Construction of the Rectum and Nerves Figure 8.14 shows the three-dimensional construction of the rectum and surrounding structures with its five “spaces.” In this figure, approximately the front left quarter of the pelvis is cut off to expose the nerves and arteries. The fascia transversalis is omitted. Also, the left half of the peritoneum is detached so that the subret-

8.14 Three-Dimensional Construction of the Rectum and Nerves

243

Subperitoneal fascia

Peritoneum

1 Retrorectal space

Fascia propria of rectum

4 Prerectal space Sup. hypogastric plexus Med. sacral a.

*

Ureter

Pre-hypogastric n. fascia Gonadal a. & v.

Iliac m.

3 Perineal body

Laterorectal space

Sup. vesical a. Lateral lig. and mid. rectal a.

Fascia of Denonvilliers and post. aspect of prostate gland

5 Pararectal space NVB and inf. vesical a.

Int. pudendal a. Ext. iliac a. Coccyx

2 Supralevator space

Int. obturator m.

Fig. 8.14  Three-dimensional construction of the rectum and nerves

roperitoneal fascia is exposed. The “retrorectal space” 1 and the “supralevator space” 2 are opened, but the rectosacral fascia, which partitions the two spaces, is unfortunately hidden behind the lateral ligament in this figure. The asterisk (∗) indicates the approximate area where the upper border of the retrorectal space is located. Let us recap what we have covered so far. The right and left hypogastric nerves branching off from the superior hypogastric plexus merge with the pelvic splanchnic nerves derived from the S2–S5 spinal nerves to form the pelvic plexus. Part of the nerve bundle branches off at

a sharp angle as the lateral ligament and runs to the side of the Rb. The lower border of the retrorectal space is formed by the rectosacral ­fascia at the midpoint, but laterally, because the fascia turns around at the lateral ligament, the space ends at a slightly higher level (this bulging area is often referred to as the “laterorectal space” 3 ). The “prerectal space” 4 is narrow in an anteroposterior direction but is wide enough in the transverse direction that it can be called the “pararectal space” 5 . The fascia lining this space also turns around at the nerve bundle. Apart from the lateral ligament, the pelvic plexus also gives

244

off branches to the urinary bladder and the prostate gland (NVB). The fascia turns around at these nerve bundles while lining them from inside. So, dissection of the pararectal space should proceed by drawing an arc toward the lateral ligament while feeling for the roundedness of the rectum. If the dissection proceeds toward the side away from the rectum, the vesical branch or NVB may be damaged, causing not only bleeding, but possibly neuropathy.

8.15 F  ascia Propria of the Rectum: Part I The last sections of this chapter are devoted to simulating dissection around the Rb in TME. Although impossible to do in actual surgery, if we proceed with dissection around the rectum by gradually scraping off surrounding structures while preserving the rectum, the result would be what is shown in Fig. 8.15. Figure 8.15a shows the Ra after retrorectal dissection has been completed. At this level, the mesorectal base, split into right and left, is opened to nearly 180 degrees and allows for passage of small nerve fibers extending from the hypogastric nerve into the rectum (rectal branches). Also, the SRA passes through the thick fat pad on the dorsal side of the rectum. These nerves and vessels are covered by the “fascia propria of the rectum” (in a narrow sense). By comparison, the ventral side of the rectum is covered by the peritoneum and the subperitoneal fascia. This subperitoneal fascia is, of course, a broad fascia lining the whole peritoneum, but in this area, there is no doubt that it is the “proper” fascia of the rectum. So, it can be interpreted that the broadly defined “fascia propria of the rectum” is a combination of the “anterior layer,” which continues from the subperitoneal fascia covering the ventral side of the rectum, and the “posterior layer,” which is the narrowly defined fascia propria of the rectum that covers the dorsal side of the rectum. It should also be noted that the broad subperitoneal fascia is referred to partially as the anterior layer of the renal fascia (fascia of Gerota) or the posterior

8  Anatomy of the Rectum and Surrounding Structures

layer of the renal fascia (fascia of Zuckerkandl), and that “the anterior layer of the fascia propria of the rectum” is a term defined in the same way. First, the peritoneum of the pouch of Douglas is incised to proceed deeper. Once a “recess” corresponding to the origin of the fascia of ­ Denonvilliers is identified, the dissection proceeds around it. Figure 8.15b shows what is seen after the dissection has proceeded to the depth of the pelvic plexus. Compared with the small nerve fibers included in the mesenteric base, the lateral ligament derived from the pelvic plexus is a robust cord-like structure and has to be cauterized off. It seems that the space above the fascia of Denonvilliers could be entered without problem in the anterior part. Dissection can advance easily between the fascia and the seminal vesicle and should be done without hesitating, although we should be careful when proceeding in an upper oblique direction so as to avoid damaging the NBV, which extends from the pelvic plexus toward the prostate gland when turning around the prerectal space. Figure 8.15c shows what is left after the lateral ligament has been dissected. Because the lateral ligament is the last structure included in the mesorectal base, cutting this results in merging the anterior and posterior layers of the fascia propria of the rectum to a single membrane that surrounds the Rb circumferentially. This is why we can regard the subperitoneal fascia covering the ventral side of the rectum as the “anterior layer” of the fascia propria of the rectum in a broad sense. This means that, when looked at from another perspective, even perfect TME produces a slit-like defect in the fascia propria of the rectum at the mesorectal base. This also applies to excising the small intestine or colon because there is no fascia at the cut edge of the mesentery. It would be difficult to proceed anteriorly due to the presence of nerve fibers from the NVB between the fascia of Denonvilliers and the posterior aspect of the prostate gland. So, we have no choice but to give up entering the space above the fascia of Denonvilliers and to cut off the fascia at this point. It seems that entering between

8.15 Fascia Propria of the Rectum: Part I

245

a

Recess (origin of fascia of Denonvilliers )

Peritoneum Subperitoneal fascia

Fascia propria of rectum

Hypogastric n. SRA

Rectal br. Fascia of Denonvilliers

b Retroprostate space (layer above)

NVB Pelvic plexus

Lateral lig.

c

Prerectal space (layer below)

Pros

tate g

land

Fascia of Denonvilliers (cut)

NVB

Subperitoneal fascia (anterior layer of the broadly defined fascia propria of rectum) Lateral lig. (dissected) Narrowly defined fascia propria of rectum (posterior layer of the broadly defined fascia propria of rectum)

Fig. 8.15  Fascia propria of the rectum: Part I

8  Anatomy of the Rectum and Surrounding Structures

246

Anterior layer that continues from subperitoneal fascia

Posterior layer that continues from the narrowly defined fascia propria of rectum

Fig. 8.16  Fascia propria of the rectum: Part II

the remnant fascia of Denonvilliers and the fascia propria of the rectum (the layer below the fascia) will allow the dissection to continue a little more.

8.16 F  ascia Propria of the Rectum: Part II Figure 8.16 shows the fascia propria of the rectum extracted from the resected TME specimen viewed diagonally from behind, a view similar

to the surgeon’s. The three arrows indicate the direction of attachment of the mesorectal base. The fascia propria has no defects other than this reverse Y-shaped attachment to the mesorectal base and surrounds the rectum and surrounding fat tissue (i.e., the mesorectum). Totally excising the mesorectum means to excise the mesentery without breaking a package named “the fascia propria of the rectum.” A full understanding of its morphology and composition is therefore very important when performing rectal surgery [15].

9

Sigmoidectomy

Abstract

The sigmoidectomy procedure described in this chapter is an introductory procedure of colectomy. Compared with other parts of the large intestine, the sigmoid colon is anatomically simpler because it has an unfused mesentery. Although sigmoidectomy is now rarely performed via open surgery, its significance remains the same even when performed laparoscopically. The standard operation time is 2 h. Keywords

Sigmoidectomy · Colectomy · Sigmoid colon

Fig. 9.1  The surgeon stands on the right side of the patient and makes a lower abdominal midline incision extending from 3  cm above the umbilicus to the upper border of the pubis. Limiting the incision to the level of the umbilicus makes it difficult to access the root of the interior mesenteric artery (IMA); incising excessively upward may result in intestinal prolapse, interfering with the procedure. We should be careful not to cut the urinary bladder when incising the lower part of the abdomen. The incision may be shorter depending on the site of the lesion and the extent of lymph node dissection needed

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_9

247

248

9 Sigmoidectomy

Fig. 9.2  After the abdominal cavity is explored, a wound retractor is placed. If the incision has been extended to the upper border of the pubis, the peritoneum should be fixed

to the skin using two sutures placed at the lower end of the wound and as close as possible to the midline for reliable fixation

Fig. 9.4  The smoothness of the subsequent procedures is substantially influenced by how the surgical laparotomy sponge is placed over the intestine. The sponge should be spread and placed so that it can wrap around the entire small intestine, rather than rolling it into a ball and squeezing it under the intestine. It is advisable to insert the sponge firmly between the small intestine and the retroperitoneum. With the left palm formed into a cup, the surgeon ade-

quately retracts the small intestine cranially, holds it for a while to confirm that the intestine does not protrude, and receives the sponge spread out. After the left palm is lifted from the retroperitoneum and the sponge is placed between the intestine and the retroperitoneum (①), the left hand is carefully removed and the sponge is inverted in such a way that it wraps around the small intestine and is spread out between the abdominal wall and the intestine (②)

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249

Cancerous lesion

Fig. 9.3  With the sigmoid colon lifted up, the small intestine is covered with a surgical laparotomy sponge and retracted cranially with an Octopus retractor. This can be

done more easily by the first assistant standing on the left side of the patient

2

Surgical laparotomy sponge Small intestine

1

SMA IMA

5

4

L3

Horizontal part of duodernum

9 Sigmoidectomy

250 IMA D3

D

Main LNs LCA

D2 S1

Intermediate LNs S2

SRA

D1

St Paracolic LNs S Sudeck point RS Ra

Rb P

Fig. 9.5 The supplying arteries and draining lymph nodes of the sigmoid colon are usually categorized into three sigmoid arteries. The first sigmoid artery (S1) most commonly branches off from the IMA as a common trunk with the left colic artery (LCA). The terminal sigmoid colon artery (St) branches off from the superior rectal artery (SRA). Because there often is no marginal artery between the St and SRA (the Sudeck point), we may recognize the St as a marginal artery between the second sigmoid colon artery (S2) and the SRA. The distance between the root of the IMA and the origin of the LCA is 3–10 cm, which may be longer than expected Lymph nodes are divided into the paracolic, intermediate (light-shaded area), and main (dark-shaded area)

lymph nodes. D0-D1 dissection is sufficient in cases of mucosal cancer. For submucosal cancer, which has been associated with a 10% prevalence of lymph node metastasis including intermediate nodes, D2 dissection should be performed. In that case, the LCA can be preserved. Cases of advanced cancer require D3 dissection, so the IMA should be ligated and divided at its root. The LCA will then be divided, typically followed by ligation of the marginal arteries between the LCA and S1. If the sigmoid colon is shorter and the cancerous lesion is located closer to the rectum, S1 can also be divided and crossed at the midpoint to preserve marginal arteries in a wider range (route indicated by the dotted line)

Fig. 9.6  The procedure to mobilize the sigmoid colon from the inner side should be started by entering the retrorectal space. The first assistant pulls the rectosigmoid (RS) laterally to the left to tautly stretch the right leaf of the mesorectum. The surgeon then makes a superficial incision on just the peritoneum with electrocautery at

2–3 cm below the cord-like structure containing the superior rectal artery (SRA) (a). The upper border of the retrorectal space (asterisk in b) is located around the iliac triangle, and the connective tissue contained in the mesorectal base is slightly dense on the proximal and loose on the distal side of this area

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251

a

SR

A

S1

IMA

Promontory

b

St S1

S2

LCA *

SR A

Slightly dense connective tissue

Loose connective tissue

9 Sigmoidectomy

252

a

Rectal branch

4 Retrorectal space 3 Pre-hypogastric n. fascia 2 Subperitoneal fascia Upper border of retrorectal space

1 Peritoneum

R hypogastric n.

b R

L 1 SRA

2

Rectal branch

3

Ureter

1

R hypogastric n. 4

2 Fascia transversalis

Gonadal a. & v.

A

A V

Mid. sacral a.

Fig. 9.7  Once the peritoneum (①) is incised, a thin fascia appears right beneath it (a). This is the subperitoneal fascia (②). Through the fascia, several small nerves (rectal branches of the hypogastric nerve) and blood vessels can be seen coursing toward the intestine. By making the incision shallower than before on the fascia with electrocautery while grasping these nerves and vessels with forceps and cauterizing them, white cotton-like loose connective

V

S1

Iliacus m. Psoas m.

tissue is exposed (③). The right hypogastric nerve should be immediately identified and caused to fall under the dissection layer. With the dissection proceeding deeper through the loose connective tissue, a space covered by spider’s web-like connective tissue (④) is entered (b). This is the retrorectal space. The tissue dissected last (③) is the thickened loose connective tissue lining the retrorectal space, that is, the prehypogastric nerve fascia

9 Sigmoidectomy

253

a

2 Subperitoneal fascia

4 Retrorectal space

242 252

253 IMA

Retrorectal space (space continues up to the vicinity of the root of IMA)

b

L SRA 2 S2

Aortic plexus

Ao IVC

Fig. 9.8  Once the retrorectal space is entered at the level of the Rs, the operation moves on to the procedure for transecting the sigmoid mesocolon at its base. After incising just the subperitoneal fascia with electrocautery (a), the mesenteric fat tissue is dissected anterior to the aortic plexus (b). Although not as loose as the retrorectal space, the presence of a distinct space in this area also helps with layer separation. The dissec-

tion proceeds to the vicinity of the root of the IMA [arrow in (a)]. The upper border of the retrorectal space, which is essentially loose connective tissue, is not clearly defined (as described in Sect. 8.9), and the space in the mesorectal base continues beyond the iliac triangle up to the vicinity of the root of the IMA, as shown in Fig. 9.6b. This is why layer separation is easy to do at the base of the sigmoid mesocolon

9 Sigmoidectomy

254

a L lumbar splanchnic n.

LCA

S1

S2 Inf. mesenteric plexus SRA Aortic plexus

Sup. hypogastric plexus

b Root of IMA

253 Fusion fascia of Toldt Monk’s white line

Inf. mesenteric plexus

Ao IVC

Subperitoneal fascia (fascia of Gerota)

Fig. 9.9  The root of the IMA should then be accessed. The right and left lumbar splanchnic nerves merge to form the inferior mesenteric plexus around the root of the IMA. The dissection proceeds while dissecting the nerve bundle extending from the inferior mesenteric plexus along the IMA into the mesocolon with electrocautery,

and the fat tissue including the lymph nodes around the root of the IMA (No. 253) is divided as the nodes lie on the resection side to expose the arterial wall (a). The artery is then ligated and divided. We must be careful not to cut the inferior mesenteric plexus (b)

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a

IMA (root) IMV

LCA

S1

S2

b IMV (root)

LCA

IMV (ligated)

IMA (ligated)

Fig. 9.10 With the sigmoid mesocolon stretched, a superficial incision is made on the peritoneum (right leaf) toward the planned intestinal transection line. Then, the fat tissue of the mesentery is dissected up to the vicinity of

the marginal arteries (a). En route, the inferior mesenteric vein (IMV) and the LCA are ligated and divided in the order they are encountered (b). The IMV usually courses 1–2 cm to the left of the IMA

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256

a

L gonadal a. & v.

Retrorectal space

LCA (ligated) L ureter IMA (ligated) Crossing point of vessels and ureter

b

Folding back Partial physiological adhesion of sigmoid mesocolon and retroperitoneum

L gonadal a. & v. L ureter

Fig. 9.11  After completing vascular dissection, we move on to mesenteric dissection (a). Although the left leaf of the sigmoid mesocolon has no peritoneal fusion like the fusion fascia of Toldt, in most cases it is folded back at its base and is partially attached to the retroperitoneum as a result of physiological adhesion occurring after birth. So, the mesenteric dissection started from inside usually enters the layer under the folded peritoneum (b). The same logic applies to the fact that in right hemicolectomy, the dissection via the medial approach enters the layer below the fusion fascia of Toldt. The mesentery is dissected toward the lateral side while staying in that layer. As the dissection advances while viewing the dissection

plane in front, we encounter the left ureter suspended from the thin subperitoneal fascia continued from the fascia of Gerota. This should be detached from the membrane with care. Around the intersigmoid recess, the ureter approaches the mesocolon at its closest point and is difficult to detach. Beyond this area, the gonadal vessels are exposed. These vessels are located more closely toward the posterior aspect of the mesocolon than the ureter, so they should be detached with greater care (b). In cases of cancer invasion, combined resection of the gonadal vessels is far more likely to be needed than that of the ureter. Once the dissection advances beyond the gonadal vessels, a sheet of stretched gauze is placed in situ

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257

a

Monk’s white line

Boundary between retroperitoneum and left leaf of sigmoid mesocolon

Intersigmoid recess

b

Gauze

Dissection advances beyond the gonadal vessels via the medial approach

Fig. 9.12 At this point, the mesenteric dissection is stopped halfway and started over from the lateral side. When the sigmoid colon is lifted toward the surgeon, the physiologically adherent retroperitoneum is also lifted up (a). The boundary between the retroperitoneum and the left leaf of the sigmoid mesocolon is identified, and then a

peritoneal incision is made along the boundary slightly close to the intestine to gain access to enter the layer above the adhered peritoneum (b). The peritoneal incision is advanced proximally along Monk’s white line up to the midpoint of the descending colon and distally up to the Rs

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258

a

Gauze (visible through retroperitoneum)

Ureter

Intersigmoid recess

Pocket

b

Retroperitoneum

Fig. 9.13  The physiological adhesion between the left leaf of the sigmoid mesocolon and the retroperitoneum often remains incomplete in the middle portion. This incomplete adhesion may result in a pocket forming, which may be entered during the dissection procedure. This pocket, whose apex is the intersigmoid recess, can be a landmark for iden-

tifying the ureter when accessed via the lateral approach (a). Once the dissection has reached this point, the preplaced gauze can be seen through the retroperitoneum. The retroperitoneum is incised and penetrated with electrocautery to remove the gauze (b). This procedure is similar to that of right hemicolectomy (explained in Fig. 6.13)

9 Sigmoidectomy Marginal a. (LCA - S1)

A

Vasa recta

LC

Fig. 9.14  After ligating and dividing the marginal vessels near the planned proximal transection line of the colon, the colonic wall is trimmed by dissecting several vessels of the vasa recta (solid arrow). Here we see dissection of the marginal arteries between the LCA and S1. If we want to preserve a longer section of proximal colon, the dissection should proceed across the S1 toward the marginal arteries between the S1 and S2, as also shown in Fig. 9.5 (route indicated by the dotted line)

259

S1

Fig. 9.15  The vessels near the distal transection line should be trimmed in the same way. Usually, the proximal rectum is also supplied by the internal iliac artery. The rectosigmoid (RS) can therefore be preserved even after the IMA has been divided at its root. The SRA may have been split into two arteries around this area. The dotted line shows the route of dissection advanced across the S1 toward the marginal arteries between the S1 and S2

S2 SR

S1

LCA (ligated) IMV (ligated) IMA (ligated)

A

260

9 Sigmoidectomy

Fig. 9.16  An intestinal clamp and a stump clamp are then placed slightly apart from each other, and the intestine is transected along the intestinal clamp with a scalpel (dotted line) Stump clamp

Intestinal clamp

Fig. 9.17  If we think excessive tension will need to be applied to the anastomosis, the dissection should proceed along Monk’s white line up to the left colic flexure to divide the splenocolic ligament (arrow). This mobilizes the descending colon to the extent that it comes down

Splenocolic lig.

9 Sigmoidectomy

261

L-shaped intestinal clamp

IMA (root)

Fig. 9.18  Intestinal anastomosis is performed using an Albert-Lembert suture. If we want to perform anastomosis at a lower level, it is advisable to use an L-shaped intestinal clamp

9 Sigmoidectomy

262

Peritoneal defect sutured closed

Fig. 9.19  After suturing the mesenteric defect closed, the abdominal cavity is washed and an 8-mm duple drain is inserted from the left abdominal wall into the pouch of

Douglas. The operation is completed by closing the abdominal wall and suturing in three layers

Low Anterior Resection of the Rectum

Abstract

This chapter describes a rectal cancer resection procedure based on the concept of total mesorectal excision proposed by Professor RJ Heald [13]. This procedure aims at resecting the rectum and the mesorectum en bloc without damaging the fascia propria of the

10

rectum, based on the understanding of the continuity of the fascia. The standard operation time is 3 h. Keywords

Total mesorectal excision · Fascia propria of the rectum · Mesorectum

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_10

263

10  Low Anterior Resection of the Rectum

264

Vas deferens

Rectal branch

Inf. epigastric a. & v. Testicular a. & v.

SRA R ext. iliac a. & v.

1 3

2

R hypogastric n.

4

Ureter

Fig. 10.1  The patient lies in the lithotomy position with the legs supported using levitator stirrups. The surgeon stands on the right side of the patient and makes an abdominal midline incision extending from 3  cm above the umbilicus to the upper border of the pubis. Once the abdomen is opened, the retrorectal space is entered following the same procedures described in Figs. 9.6 and 9.7 on sigmoidectomy. The first assistant pulls the rectosigmoid (RS) laterally to the left to apply tension to the right leaf of the mesorectum. The surgeon then makes a superficial incision just on the peritoneum (①) with electrocautery 2–3 cm below the cord-like structure containing the superior rectal artery (SRA). A thin fascia (subperitoneal

fascia ②) immediately appears under the peritoneum, and through this fascia, several small nerves (rectal branches of the hypogastric nerve) and blood vessels can be seen coursing toward the intestine. Making an incision shallower than before on the fascia with electrocautery while grasping these nerves and vessels with forceps and cauterizing them exposes white cotton-like loose connective tissue, the prehypogastric nerve fascia (③). When advancing the dissection through the fascia while detaching the suspended right hypogastric nerve from the dissection layer, a space covered by spider’s web-like connective tissue, the retrorectal space (④), is entered

10  Low Anterior Resection of the Rectum

265

L

R

Rectal branch

1 SRA

L hypogastric n.

2 3 R hypogastric n.

4

Subperitoneal fascia

Gonadal a. & v.

Fascia transversalis

Ureter Pre-sacral fascia Med. sacral a.

R common iliac a.

Iliacus m.

R common iliac v.

Fig. 10.2  Route for entry into the retrorectal space. By advancing the incision in the order of the ① peritoneum, ② subperitoneal fascia, and ③ prehypogastric nerve fascia, the retrorectal space (④) is entered. Attempting to enter the retrorectal space without the first assistant applying sufficient traction to the rectum may result in iatrogenic transection of the hypogastric nerve

Next, as done in sigmoidectomy, the incisional line on the right leaf of the mesorectum is extended proximally for detachment of the sigmoid mesocolon. While confirming that the superior hypogastric plexus, which is upstream of the hypogastric nerve, and the aortic plexus remain intact under the dissection layer, the incision is advanced to the vicinity of the root of the inferior mesenteric artery (IMA)

10  Low Anterior Resection of the Rectum

266 IMA IMV

LCA

D

1 2

S1 Dissection range when S1 is preserved S2

SRA

3 St 4

S RS

Ra

Rb P

Fig. 10.3  Range of dissection and where to divide the arteries. In low anterior resection, the left colic artery (LCA) should be preserved whenever possible to maintain blood flow to the proximal intestine, except in cases of positive No. 252 lymph nodes. So, the IMA should be divided beyond the bifurcation of the LCA (➊) after dissecting the No. 253 lymph nodes around the root of the IMA.  The first sigmoid colon artery (S1) often shares a common trunk with the LCA. In this case, S1 can also be preserved to limit the dissection range as indicated by the

dotted line. However, when creating an anastomosis at a low level, because excessive tension is more likely to be generated by a stretched mesentery than by the proximal intestine, dissection is performed in most cases within the range indicated by the solid line, followed by division of S1 at position ➋. Then, the second sigmoid colon artery (S2) and the terminal sigmoid colon artery (St) are divided at positions ➌ and ➍, respectively, to preserve as many marginal arteries as possible

10  Low Anterior Resection of the Rectum

267

a

Lumbar splanchnic n. IMV

LC A

Root of IMA

S1 No.253 LN

b

IMV (ligated)

S1 IMA (ligated)

Fig. 10.4 Actual operative situation. When the peritoneal incision on the right leaf of the sigmoid mesocolon approaches the horizontal part of the duodenum, the incisional line is curved along an arc to turn around the root of the IMA. The fat tissue containing the No. 253 lymph nodes is scraped off with electrocautery to expose the IMA surrounded by nerve bundles. We need to be careful to avoid cutting the inferior mesenteric plexus and to preserve the lumbar

splanchnic nerves. The IMA is ligated and divided beyond the bifurcation of the LCA (a), and the IMV is also ligated and divided at the same level. At this point, the course of the S1 is determined, and if it is like that shown in (b), S1 is ligated and divided at an adequate distance from the bifurcation. Vascular dissection of the mesentery is discontinued at this point; the marginal arteries and intestinal transection will be dissected immediately before anastomosis (see Fig. 10.23)

10  Low Anterior Resection of the Rectum

268

Fascia propria of rectum Rectal br.

Sigmoid mesocolon

Cut edge of prehypogastric n. fascia R ureter Cut edge of peritoneum

IMA (ligated)

No.253 LN S1 (ligated) L ureter Sup. hypogastric plexus

LCA

S1 (ligated)

Fig. 10.5  Following division of the vasculature, the sigmoid mesocolon is dissected as described in Figs. 9.11– 9.13. The dissection starts from the inner side and advances until the left ureter and the left gonadal vessels are passed. Then, the left leaf of the sigmoid mesocolon is incised along Monk’s white line and penetrated while releasing physiological adhesions The surgeon then moves to the left side of the patient and starts retrorectal dissection. The second assistant stands between the patient’s legs, pulls up the rectum, and retracts it caudally with a long flat rectal retractor. The

IMV (ligated)

retrorectal space is entered through its opening and the dissection proceeds as if breaking a spider’s web. By slightly activating the electrocautery, the spider web threads are diffused circumferentially as if being melted and the site is increasingly cleared. Dissection continues by drawing an arc with the tip of the electrocautery, keeping in mind the concave anterior surface of the sacrum. As the dissection proceeds deeper, the second assistant repositions the rectal retractor deeper so that the rectum can be accurately retracted with the tip of the retractor

10  Low Anterior Resection of the Rectum

269

Fascia propria of rectum

Peritoneum

Subperitoneal fascia LCA S1

SRA

IMA Ao Fascia transversalis 4 5 1 2 Sup. hypogastric plexus 3 5

Hypogastric n.

4

Prehypogastric n. fascia

NVB

Mid. sacral a. Anococcygeal body

Pelvic plexus

Rectal br.

Fig. 10.6  In this sagittal cross section, the dense connective tissue lining the rectal side of the retrorectal space represents “the fascia propria of the rectum.” However, if we define the fascia encompassing the entire rectum as the fascia propria of the rectum, this membrane is the posterior layer (see Sect. 8.15 on the anatomy of the rectum and surrounding structures). On the sacral side of the retrorectal space, the middle sacral artery can be seen through the

Presacral fascia

“prehypogastric nerve fascia.” The accompanying middle sacral vein and the sacral venous plexus are also in the same layer. Underneath this layer lie the presacral fascia, fascia transversalis, and sacrum. As mentioned in Sect. 8.9, the presacral fascia is a part of the broad fascia surrounding the subperitoneal fat tissue from the lateral side. If the presacral fascia is exposed, then the retrorectal dissection has gone too deep

10  Low Anterior Resection of the Rectum

270 Peritoneal inversion

a

Tumor Rectal br.

R ureter R hypogastric n. Dissected rectal br.

b

Fascia propria of rectum Retrorectal space

R hypogastric n. Mid. sacral a. Dissected rectal br.

Prehypogastric n. fascia Subperitoneal fascia

Peritoneum

Fig. 10.7  After the posterior dissection has reached a certain point, the dissection also needs to proceed laterally. On both sides of the rectum, the peritoneal incision is extended up to the point of peritoneal inversion (arrows in a). The fat tissue of the mesentery is then incised with electrocautery. This fat tissue is not thick at all but is

crossed by small nerve fibers extending from the hypogastric nerve to the rectum (rectal branches). We should be careful not to cut these nerves because pulling the rectum has also caused the hypogastric nerve to come closer to the rectum (arrow in b). The ureter also approaches the rectum in this area, so it should be identified beforehand

10  Low Anterior Resection of the Rectum

271

a

Rectosacral fascia

b

1 2 3 5

Supralevator space

Retrorectal space

4

Rectosacral fascia

Fig. 10.8  We return now to dissection of the retrorectal space. As the dissection further advances caudally, dense connective tissue of a distinct nature is reached. This is the rectosacral fascia and is the furthest limit of the retrorectal space, located at the level of the fourth sacral vertebra. In this area, where the rectum most closely approaches the sacrum, the connective tissues lining the rectal and sacral sides of the retrorectal space are fused, forming this mem-

branous fascia. This fascia is carefully incised and penetrated using activated electrocautery (a). Once the rectosacral fascia is passed, the resistance is again diminished and another space covered by a spider’s web, the supralevator space, is entered (b). This time, the dissection proceeds deeper while viewing the coccyx and the levator ani muscle through the dorsal fascia

10  Low Anterior Resection of the Rectum

272

a

4

5

3

Transection line of rectosacral fascia 1

b

4 Fascia propria of rectum

Transection line of rectosacral fascia

5

Med. sacral a.

Anococcygeal body 3

2 Presacral fascia 1 Prehypogastricn. fascia

Fig. 10.9  The prehypogastric nerve fascia (➊) forming the posterior wall of the retrorectal space fuses with the presacral fascia (➋), which has descended along the sacrum, beyond the rectosacral fascia after reaching the coccyx, forming a single layer (➌). This fascia expands while cover-

ing the levator ani muscle and its tendon of insertion at the anococcygeal body, and finally merges (➎) with the fascia propria of the rectum (➍), which has descended on the rectal side of the space (a). Incising between these fascias with electrocautery is the final step in retrorectal dissection (b)

10  Low Anterior Resection of the Rectum

273

Lateral lig. Rectal br. Pelvic plexus

S4

Pelvic splanchnic ns.

S3 Incision point where presacral fascia merges with fascia propria of rectum ( 5 in Fig. 10.9)

S2

Transection line of rectosacral fascia

Fig. 10.10  The lateral dissection advances deeper on both sides of the rectum. On the lateral wall of the retrorectal space, the S2–S4 pelvic splanchnic nerves entering the pelvic plexus can be seen through the prehypogastric nerve fascia and have a snowboard half-pipe-like appearance. As the rectum is lifted and pulled up, the pelvic

splanchnic nerves are also lifted toward the intestine and their several rectal branches are stretched so tight that they prevent the expansion of the retrorectal space. Dissecting these branches one by one with electrocautery causes the pelvic plexus to fall toward the pelvic wall and the rectum to be lifted further

10  Low Anterior Resection of the Rectum

274

a

Bladder

Recess

Tumor

b

A

B

Fig. 10.11  The peritoneum on the anterior surface of the rectum is incised. While the second assistant applies a rectal retractor to the pouch of Douglas and applies force to the tip, the first assistant pulls the rectum cranially to remove slack at the site of peritoneal inversion. Still, a slight recess remains at the midpoint, which is the origin of the fascia of Denonvilliers formed by fusion of the inverted peritoneum (a). If we consider the fascia of Denonvilliers as the rectal version of the fusion fascia of Toldt, then this recess corresponds to Monk’s white line. The standard pre-

rectal dissection procedure involves entering the layer above the fascia of Denonvilliers. So, the route for the peritoneal incision in the pouch of Douglas should pass outside the recess following the larger dotted line (A in b). However, if the tumor is localized in the posterior wall, the layer below Denonvilliers’ fascia may be entered by following the smaller dotted line (B in b) (see Fig.  10.19). The layers above and below the fascia of Denonvilliers are officially referred to as the “retroprostate space” and “preprostate space,” respectively

10  Low Anterior Resection of the Rectum Fig. 10.12  While the first assistant pulls the rectum cranially, the surgeon grasps and everts the edge of the incised peritoneum of the pouch of Douglas with forceps to expose the seminal vesicle (covered by the subperitoneal fascia) located anterolateral to the rectum. While applying appropriate tension to the loose connective tissue between the seminal vesicle and posterior aspect of the peritoneum, the tissue is incised and dissected with electrocautery (a). The dissection is now connected to the dissection layer from the lateral side (Fig. 10.10). The sagittal cross section in (b) shows the dissection route continuing to enter the layer above the fascia of Denonvilliers [16]

a

275 Ampulla of vas deferens

Seminal vesicle

b

Seminal vesicle

Prostate Pouch of Douglas

Fascia of Denonvilliers

10  Low Anterior Resection of the Rectum

276

a Sup vesical a. NVB Inf. vesical a. Obturator a.

Ureter

Fascia of Denonvilliers

Mid. rectal a. Lateral lig

Lat. umbilical lig.

b

Prostate

Vas deferens

Bladder Seminal vesicle

NVB Ureter Sup vesical a.

Retroprostate space

Obturator a.

Fascia of Denonvilliers

Inf. vesical a. Prerectal space Fascia propria of rectum

Pelvic plexus SRA

Int. pudendal a.

Prehypogastric n. fascia Pelvic splanchnic n. Mid. sacral a. Lateral lig.

Fig. 10.13  The seminal vesicle is detached from the fascia of Denonvilliers with electrocautery. This fascia is a robust membranous connective tissue with pasteboard-like appearance, through which small blood vessels contained in it can be seen. Here again, the first assistant should pull

Hypogastric n. Mid. rectal a.

the rectum cranially with enough force to facilitate layer separation (a). Although it is preferable to adequately extend the dissection bilaterally (dotted line in b), we should advance the dissection carefully to avoid damaging the neurovascular bundles (NVB) located on both sides

10  Low Anterior Resection of the Rectum Fig. 10.14  The next step is to divide the lateral ligament. The second assistant applies two rectal retractors on both sides of the lateral ligament to retract the seminal vesicle and the lateral pelvic wall outward. With the index and middle fingers placed on both sides of the lateral ligament, the surgeon pulls the rectum craniomedially to apply appropriate tension to the ligament. This makes the lateral ligament look like a wedge driven from the pelvic plexus into the lateral wall of the rectum. The narrowed portion near the tip of the wedge is divided with electrocautery (a). The middle rectal artery contained in the lateral ligament (b) does not need to be ligated as long as it is cut slowly with electrocautery

277

a

NVB

Lateral lig.

b

Dissected layer above fascia of Denonvilliers (retroprostate space)

Inf. aspect of prostate gland

10  Low Anterior Resection of the Rectum

278 Fig. 10.15 Once the lateral ligament is penetrated, the dissection advances to in front of the fascia of Denonvilliers and connects to the dissection layer (Fig. 10.13). When passing through this area, we must avoid cutting the NVB. Keep in mind that as the rectum is pulled, the NVB is also pulled toward the rectum and forms a tent-like shape. The dissection should then proceed while identifying the boundary between the nerve fibers and the connective tissue to be dissected (arrow in a). The tension applied to the NVB is greatest around the edge of the fascia of Denonvilliers. Dissecting this area results in exposure of the lateral border of the fascia (asterisk in a and b)

a

NVB

Lateral lig. (cut) *

b

*

Mid. rectal a.

Lateral border of fascia of Denonvilliers

Lateral lig. (cut)

10  Low Anterior Resection of the Rectum

279

Nerve fibers between prostate and fascia of Denonvilliers

a

NVB

R margin of fascia of Denonvilliers

Lateral lig. (cut) Fascia of Denonvilliers A

Lateral lig. (cut) Fascia propria of the rectum B

b

A Nerve fibers from NVB

B

Perineal body

Layer below fascia

Fig. 10.16  Division of the fascia of Denonvilliers: The fascia of Denonvilliers (A) is attached to the perineal body. In men, the presence of nerve fibers from the NVB between this fascia and the posterior surface of the prostate means that it is difficult to detach the fascia from the prostate from inside the abdominal cavity. We therefore need to divide the fascia of Denonvilliers at the level of the inferior aspect of

the prostate so that the dissection layer can be changed to the layer below the fascia (b). After a small incision is made at the midpoint of the fascia of Denonvilliers, right-angled dissecting forceps are slid under the fascia to dissect connective tissue and the fascia is divided with electrocautery. By extending this incision to the right and left, the fascia can then be divided [arrows in (a)]

10  Low Anterior Resection of the Rectum

280

a Inf. aspect of prostate gland Cut edge of fascia of Denonvilliers (remnant side) A

Fascia propria of rectum B Cut edge of fascia of Denonvilliers (resection side) A ' Lateral lig. (cut)

Rectal br. (cut)

b

A

B

A' ’

Fig. 10.17  Once Denonvilliers’ fascia is divided, the rectum can now be pulled further upward (a). The dissection of the layer below Denonvilliers’ fascia is advanced one step deeper to complete the anterior dissection (b)

10  Low Anterior Resection of the Rectum

281

a Vagina

Fascia of Denonvilliers A

Fascia propria of rectum B

b

A

B

Fig. 10.18 In women, a relatively loose adhesion between the posterior vaginal wall and the fascia of Denonvilliers allows the dissection to proceed to the vicinity of the perineal body with the fascia remaining

attached to the rectum (the layer above the fascia remains intact). Women also have a wider pelvic cavity, which, combined with the abovementioned features, provides good conditions for performing rectal cancer surgery

10  Low Anterior Resection of the Rectum

282

a Bladder

Cut edge of peritoneum of pouch of Douglas (remnant side)

Recess

A

Fascia of Denonvilliers (reverse side)

B Fascia propria of rectum Transection line of rectosacral fascia

b

A

Layer below fascia

Tumor B

Fig. 10.19  If the tumor is localized to the posterior wall with limited depth of invasion, the layer below the fascia of Denonvilliers can be entered from ab initio as shown in (a). Although this might be a little difficult to enter, this

dissection route is safer because the connective tissue is detached and lifted along with the fascia of Denonvilliers, so the NVB is not encountered (b)

10  Low Anterior Resection of the Rectum

283

a

Incision in fascia of Denonvilliers (remnant side) A

Fascia propria of rectum B

Fascia of Denonvilliers to be included in resected specimen A'

b

A

A'

B D

B

C

Fig. 10.20  After applying an L-shaped intestinal (rectal) clamp to the rectum distal to the tumor, the lumen of the rectum is washed. Although the fascia of Denonvilliers A has been removed, the fascia propria of the rectum B still circumferentially surrounds the rectum (a). If the retrorectal dissection shown in Fig. 10.9 has been adequately advanced

distally, the fat C between the fascia propria of the rectum and the muscle layer of the rectum D should be thin enough not to interfere with anastomosis (b). If this fat layer remains thick, because it remains on the resection side and obscures the view, it should be removed so that the muscle layer near the planned intestinal transection line can be exposed

10  Low Anterior Resection of the Rectum

284

a

Fascia of retroperitoneum (broadly defined as fascia propria of rectum) B '

Bladder Pouch of Douglas

Peritoneum E

Dissected br. of rectal n.

Fascia propria of rectum B

Rectal wall (mucosal + muscular layers) D

Fat of mesorectum C SRA

b

B'

D

E

C B D

Fig. 10.21  If the tumor is located proximal to the site of peritoneal inversion (Ra, RS) (this figure and Fig. 10.22), we should perform tumor-specific mesorectal excision. To

do this, the fat of the mesorectrum C has to be peeled off around the planned intestinal transection line

10  Low Anterior Resection of the Rectum

285

a

b

Fascia propria of rectum Br. of SRA

Muscle layer of rectum

Muscle layer of rectum

Fig. 10.22  On both sides of the rectum, the mesorectum is divided with a clamp inserted along the lateral wall of the rectum (a). Once the muscle layer is exposed, the clamp is inserted into the fat tissue along the surface of the muscle layer. The fat tissue is then scooped transversely and cut with electrocautery. The fat tissue contains several

branches of the superior rectal artery (SRA) and vein, which should be ligated and divided once identified (arrow in b). This results in the posterior half of the circumference of the rectum not being covered by the fascia or serosa, and the muscle layer is exposed

10  Low Anterior Resection of the Rectum

286

a

St

S2

S1 IMA (ligated)

b Stump clamp

Fig. 10.23 Dissection of the sigmoid mesocolon. Typically, S2 is ligated and divided, followed by ligation and division of the marginal arteries between S2 and St (dotted arrow in a) (see also Fig.  10.3). After trimming around the intestinal transection line, a purse-string suture clamp is applied and a 2-0 nylon suture with straight needles at both ends is passed. Slightly away from the clamp, a stump clamp is applied on the resection side of the rec-

tum and the rectum is transected with a pointed blade. After expanding the sigmoid colon stump to form a triangle using three pairs of intestinal grasping forceps and inserting the anvil of a circular stapler into the opening, the colon is suture-fixed to the anvil shaft with the preplaced nylon suture (b). A 33-mm circular stapler is commonly used in low anterior resection

10  Low Anterior Resection of the Rectum Fig. 10.24 Transection of the rectum: With the rectum pulled cranially with enough force, a linear stapler is applied along the distal side of the rectal clamp to transect the rectum. Because the rectum is transected at the ampulla in low anterior resection, when we think that we cannot achieve transection with one firing, we can do a planned two-fraction transection instead. More specifically, the first firing of the linear stapler is done so that the seam of the staple line is around the midpoint of the planned anastomosis made by a circular stapler. If we are too conservative in the first firing, this might leave a long distance to be cut by the second firing. So, we should do the first firing intending to cut about 60–70% of the width of the intestine (a). For complete transection, we should do the second firing with the rectum scooped and pulled with a strong curved clamp (b). In either case, we should try to make the staple line as short as possible and as perpendicular as possible to the short axis of the rectum

a

b

287 Rectal ampulla

288 Fig. 10.25  A circular stapler is inserted through the anus and the center rod is pulled slowly out of the rectal wall. Before the rod penetrates the intestinal wall, the advance of the rod is stopped and fine adjusted so that its tip comes out just beside the seam of the staple line. After connecting the center rod to the anvil and confirming that there is no torsion of the colon or inclusion of other tissues in the anastomosis, the circular staple is fired

10  Low Anterior Resection of the Rectum

10  Low Anterior Resection of the Rectum

289 Reconstructed pouch of Douglas

S2

Drain placed in front of sacrum

S1 (root) S1

SRA (root)

Preserved marginal a. LCA

Fig. 10.26  After washing the pelvic cavity and confirming hemostasis, the cut edge of the retroperitoneum on the right and the cut edge of the sigmoid mesocolon are sutured to reconstruct the retroperitoneum. The anastomosis is concealed under the retroperitoneum, which helps reduce tension to the anastomosis and, in

case of anastomotic leak, limit abscess formation within the pelvic cavity After inserting a drain via the left abdominal wall and placing it near the anastomosis in front of the sacrum, the operation is completed by closing the abdominal wall, suturing in three layers

11

Abdominoperineal Resection of the Rectum

Abstract

Although advances in lower level anastomosing techniques have substantially reduced the use of the Miles’ operation for rectal cancer, this surgical procedure is still a good option for advanced rectal cancer when there is a limited distance between the tumor and the distal intestinal transection line. The standard opera-

tion time is 4 h, including the time needed to change the patient’s body position. Keywords

Lower-level anastomosing techniques · Distal intestinal transection line · Advanced rectal cancer

Ant. wall of rectus sheath

Fig. 11.1  After completing the intraabdominal procedure to detach the rectum from the surrounding structures, the blood vessels of the sigmoid mesocolon are ligated and divided and the intestine is transected using a linear stapler. While the preoperatively marked planned colostomy site on the skin is grasped and lifted with a Kocher clamp, a 2–3-cm round skin

incision is made with a scalpel, with care taken not to make the incision too large. The subcutaneous tissue is divided with a flat retractor to expose the anterior rectus sheath. A cruciate incision is made with a scalpel, and a Kocher clamp is applied to the edge of the incision (which is helpful for later fixing the stoma to the anterior rectus sheath)

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_11

291

11  Abdominoperineal Resection of the Rectum

292 Fig. 11.2  To secure a path for the stoma, the left index and middle fingers are inserted from the dissected margin of the left leaf of the sigmoid mesocolon into the retroperitoneal space. The fingers are advanced toward the anterior abdominal wall until reaching directly under the planned colostomy site, where the round skin incision had already been made

Sigmoid colon (Cut edge)

R ureter

Rectum

Fig. 11.3  The rectus abdominis muscle bundle is opened vertically with a retractor and the posterior sheath is incised. The opening should be large enough to allow for passage of the index and middle fingers. To avoid cutting through the peritoneum, both fingers are placed beneath the muscle to guide in cutting the posterior sheath only

Post. wall of rectus sheath

11  Abdominoperineal Resection of the Rectum Fig. 11.4 Dissection forceps are inserted through the opening into the abdominal cavity to grasp the stump of the sigmoid colon and withdraw it while ensuring there is no torsion. The withdrawn portion of the colon should be long enough to prevent later retraction of the stoma. The anterior rectus sheath and the seromuscular layer of the sigmoid colon are fixed by several interrupted 3-0 Vicryl sutures. In addition, a Kocher clamp is applied to the intestinal stump as a “weight”

Fig. 11.5 After washing the pelvic cavity and confirming hemostasis, the rectum is repositioned as shown (arrow) so that it can be easily withdrawn later during perineal manipulation. The retroperitoneum is repaired with a running 3-0 Vicryl suture. In women, it is advisable to have the uterus retroflexed and sutured bilaterally to the retroperitoneum before repairing the retroperitoneum

293

Cut edge of sigmoid colon

Cut edge of retroperitoneum

Mid. sacral a.

Rectum

Sigmoid colon

294 Fig. 11.6  The abdominal wall is then closed by suturing in three layers. A protection film is applied to the wound and then the stoma is fixed to the skin. The intestine is transected along the staple line, and the resulting opening is fixed to the skin with about 12 interrupted 3-0 Vicryl sutures. A protruding stoma can then be created by applying one suture to a part of the intestinal wall while fixed to the skin

Fig. 11.7  The patient is repositioned in the jack-knife position. The anus is closed with a purse-string suture. In women, the vagina should be washed thoroughly. A spindle-­shaped skin incision is made between the lower border of the coccyx superiorly and the perineal body (asterisk) inferiorly

11  Abdominoperineal Resection of the Rectum

11  Abdominoperineal Resection of the Rectum

295

a

b

Incised rectosacral fascia Cut edge of resected specimen

Supralevator space

Perineal body Dissected fascia of Denonvilliers

Stoma Repaired retroperitoneum (reverse side)

Fig. 11.8  The fat tissue surrounding the external anal sphincter is dissected with electrocautery (a). This fat tissue contains branches of the inferior rectal artery but can usually be ignored. The dissection should proceed with some force until reaching the layer through which the anococcygeal ligament and the levator ani muscle can be

seen. Arrows in the sagittal cross section (b) show the dissection route. The resected specimen is placed as shown in (b) and the peritoneum is suture-repaired. The fascia of Denonvilliers has been partially detached, remaining attached to the rectum until halfway, and it is dissected at the level of the inferior aspect of the prostate

11  Abdominoperineal Resection of the Rectum

296

Male

Anococcygeal body

Female

Coccyx

Gluteus maximus m. Inf. rectal a.

Levator ani m. Ext. anal sphincter

Obturator internus m.

Sup. transverse perineal m. Ischial tuberosity Perineal body

gracilis m.

Urogenital diaphragm

Ischiocavernosus m.

Bulbospongiosus m.

Bulbospongiosus m.

Urethral orifice

Clitoris

Fig. 11.9  Surgeon’s view of the perineal anatomy. Left: male. Right: female

11  Abdominoperineal Resection of the Rectum Fig. 11.10 Curved dissection forceps are inserted from the right lateral side of the anococcygeal body into the abdominal cavity. A relatively thick and dense ligament is then scooped with the forceps and divided with electrocautery

Fig. 11.11  The levator ani muscles bilaterally are dissected up to the 3 and 9 o’clock positions, respectively (arrows). After inserting the index finger into the abdominal cavity to assess the thickness of the levator ani muscle, curved dissection forceps are inserted into the abdominal cavity to guide dissection with electrocautery. Note that inadequate intraabdominal dissection complicates this procedure, so it is advisable to perform the intraabdominal dissection procedure adequately, rather than postponing it, thinking that it can be done from the bottom later

297 Coccyx Anococcygeal body

Pelvic cavity Levator ani m.

11  Abdominoperineal Resection of the Rectum

298 Fig. 11.12  The rectum is withdrawn out of the wound, following which the dissection of the bilateral levator ani muscles is advanced downward (arrow)

Anococcygeal body (divided)

Fig. 11.13  This sagittal cross section of the surgical area shows the rectum withdrawn. The rectum comes out while turning around the perineal body (arrow), like performing a giant swing on a horizontal bar. Note that the rectum is now upside down

Anococcygeal body (divided)

Pelvic cavity

Perineal body

Abdominal cavity Withdrawn rectum

11  Abdominoperineal Resection of the Rectum

299

a

Anococcygeal body (divided) Prostate Seminal vesicle Distal part of fascia of Denonvilliers (remnant side) A

Fascia of Denonvilliers to be included in resected specimen B Lateral lig. (cut) C

b

Layer below fascia

B

A C

Fascia propria of rectum

Fig. 11.14  If the fascia of Denonvilliers has been dissected intraabdominally, the end portion of the remaining fascia covers the prostate gland as shown in (a). With tension applied by pulling the rectum with the left hand, the connective tissue attached to the fascia propria of the rec-

tum (corresponding to the layer below the fascia of Denonvilliers) is dissected with electrocautery (b). This dissection layer can be seen just anteriorly in the jackknife position, providing a much better operative view than from the abdominal cavity

11  Abdominoperineal Resection of the Rectum

300 Fig. 11.15  Finally, the perineal body is dissected with electrocautery so that the specimen can be excised. For localized cancer of the posterior wall, it is safer to leave the end portion of the fascia of Denonvilliers on the prostate side as shown in (a). A sagittal cross section is shown in (b). We can also enter the layer below the fascia of Denonvilliers ab initio (as described in Fig. 10.19 on low anterior resection) and leave the entire fascia behind

a

Distal part of fascia of Denonvilliers (remnant side) A

Perineal body

b

Perineal body A

11  Abdominoperineal Resection of the Rectum Fig. 11.16  However, when the rectal cancer is located so close to the anus, it is generally advisable to dissect the entire length of the fascia of Denonvilliers remaining attached to the rectum. In such cases, we need to advance the dissection to the perineal body while staying in the layer above the fascia of Denonvilliers, and this inevitably requires detachment between the posterior surface of the prostate and the fascia of Denonvilliers. So, intraabdominal anterior dissection should be discontinued at the inferior aspect of the prostate and the latter half of the dissection should be performed in the jack-knife position, which provides a better operative view. On both sides of the prostate gland, nerve fibers from the neurovascular bundle; NVB, along with small blood vessels, enter between the prostatic capsule and the fascia of Denonvilliers as shown in (a). These nerve fibers and vessels should be carefully ligated and divided as the dissection proceeds. Although the area to be dissected is limited, note that any careless dissection in this area might cause massive bleeding. Once the perineal body is reached, it is dissected with electrocautery and the specimen is excised (b). Compared with Fig. 11.15, this figure shows that the completely dissected fascia of Denonvilliers fully covers the anterior surface of the rectum and is excised without damaging the layer below the fascia

301

a Prostate

Nerve fibers and vessels from NVB

Dissected fascia of Denonvilliers D

b Layer below fascia

D Perineal body

11  Abdominoperineal Resection of the Rectum

302 Fig. 11.17  In women, a relatively loose adhesion between the posterior vaginal wall and the fascia of Denonvilliers allows the intraabdominal anterior dissection to advance to the very vicinity of the perineal body with the fascia remaining attached to the rectum (the layer above the fascia remains intact) (see Fig. 10.18 on low anterior resection). After the patient has been repositioned in the jack-knife position, the dissection proceeds with electrocautery guided by the left index finger inserted into the vagina, while identifying the boundary between the posterior vaginal wall and the fascia of Denonvilliers (a), until finally the perineal body is dissected (arrow in b). This way, the specimen can be excised without cutting the layer below the fascia of Denonvilliers. Nerves and vessels on both sides of the vagina should also be ligated and divided, although this does not require the same level of extreme care that is needed for dissection around the prostate gland

a

Uterus

Vagina

Fascia of Denonvilliers D

b

D

11  Abdominoperineal Resection of the Rectum Fig. 11.18  After washing the pelvic cavity thoroughly with an enema tube and confirming hemostasis, an 8-mm duple drain tube is inserted from the right side of the wound up to the anterior surface of the sacrum and fixed. The wound is closed by suturing in two layers using interrupted 3-0 Vicryl sutures, sequentially from the deeper skin layer to minimize dead space, followed by a 3-0 nylon skin suture to complete the operation

Perineal body

303

Surgical Repair of Rectal Prolapse: The Altemeier Procedure

Abstract

You may wonder why a minor operation like rectal prolapse repair is included in this book on major gastrointestinal operations. We include it because it provides a good opportunity to understand the rectal anatomy by viewing it from a different angle. This chapter describes an established rectosigmoidectomy

12

procedure via the perineal approach, commonly known as the Altemeier procedure. The operation time is 1 h. Keywords

Rectal prolapse repair · Perineal rectosigmoidectomy · Altemeier procedure

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_12

305

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

306

a

Mucosal layer Muscular layer

①

②

④

③

b Urogenital diaphragm

Fascia of Denonvilliers

Perineal body Levator ani m.

Abdominal cavity Outer tube Inner tube

tr

Re Supra

levato

tal

c ore

e

ac

sp

r spac

e

Dentate line Mesorectum

Int. anal sphincter

Rectosacral fascia Ext. anal sphincter

Fig. 12.1  Various complex factors are thought to cause rectal prolapse, including ① an excessively long sigmoid colon, ② a deep and wide pouch of Douglas, ③ thinning of the rectosacral fascia, which supports the posterior wall of the rectum, and ④ a relaxed and widened external anal sphincter. The sagittal cross section (a) illustrates these abnormalities in a way that figures in previous chapters did not: it distinguishes between the mucosal and muscular layers of the rectal wall (white and shaded layers, respectively). When the rectum is prolapsed, the rectal wall becomes dual structured, consisting of the outer and inner

Anococcygeal body

tubes (b). The upper half of the space between the outer and inner tubes is a sac-like “abdominal cavity” formed by the descent of the pouch of Douglas along the route indicated by the arrows. The lower half of the space consists of the “mesorectum,” which is the fat tissue on the posterior side of the rectum, and loose connective tissue contained in the retrorectal space and supralevator space. The pelvic floor muscles and the fascia of Denonvilliers are pulled by the prolapsed rectum and deformed. The following figures show the step-by-step repair procedure toward achieving the goal shown in Fig. 12.12

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure Fig. 12.2  The tip of the prolapsed rectum is grasped and pulled with intestinal grasping forceps. In cases of mild prolapse, it is advisable to ask the patient to bear down on the rectum so that it can be grasped before anesthesia takes effect. An incision is made with electrocautery on the outer tube about 1 cm away from the dentate line parallel to the short axis of the rectum (a). Both the mucosal and muscular layers of the outer tube are incised (arrow in b). It may be difficult to penetrate the muscular layer due to marked thickening of the rectal wall resulting from repeated prolapse and reduction. Also, hemostasis must be confirmed while proceeding with the incision of the well-­vascularized tissue

307

a Dentate line

1 cm

b

Mucosal layer Muscular layer

Dentate line

Subperitoneal tissues

Dentate line

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

308 Fig. 12.3 The peritoneum is reached by dissecting to a depth of about 5 mm (a). It is grasped and lifted with forceps and incised with electrocautery to enter the extended “abdominal cavity” (arrow in b)

a

Peritoneum

b Incised peritoneum

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure Fig. 12.4 After confirming the thickness of the outer tube, the “mucosal plus muscular layer” is incised circumferentially at a constant distance (1 cm) from the dentate line (a and sagittal cross section in b). An ultrasonically activated scalpel may be used to advance the procedure with reduced bleeding (a)

309

a Mucosal and muscular layers of outer tube

Abdominal cavity Peritoneum

b

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

310

a

b

Ext. anal sphincter

*

L border of peritoneal sac R border of peritoneal sac

Serosa of inner tube Subperitoneal tissue Mucosal and muscular layers

c

Widely opened peritoneal sac

Fig. 12.5  Grasping the cut edge of the peritoneum with forceps, the incision is extended to the right and left guided by right-angled forceps placed under the peritoneum (a). On reaching the border of the peritoneal sac, the

incision is turned around and advanced up to the transition to the serosa of the inner tube (asterisk in b). White arrows in (b) and (c) indicate communication with the abdominal cavity

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

311

a

Serosa of inner tube B Mucosal and muscular layers of outer tube A Loose connective tissue inside mesorectum C Br. of superior rectal a.

Ext. anal sphincter

b A B

A C

Br. of superior rectal a.

Fig. 12.6  The lower half of the circumference of the inner tube is inside the mesorectum and has no communication with the abdominal cavity. There are many small vessels branching from the superior rectal artery in this area. Loose connective tissue is dissected sequentially from the superficial layer while carefully sealing these vessels with an ultrasonically activated scalpel until the muscular layer is reached. In this step, dissecting at a constant distance of about 1 cm from the external anal sphincter while applying appropriate tension to the mesorectum by pulling the inner tube (a) will help to adequately with-

draw the excess intestine and naturally reduce slack of the intestine inside the body. In short, the mesorectum is dissected obliquely and proximally toward the intestinal wall. Because the dissected vessels are immediately drawn back deep into the connective tissue due to the tension applied, note that inadequate sealing of the vessels may result in difficult-to-control bleeding At this point, the upper half of the circumference of the inner tube is covered by the serosa, while the muscular layer is exposed in the lower half (b)

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

312

a 30 Vicryl detach

b

Sutured A

Newly created pouch of Douglas

B

A

C

Fig. 12.7  After the rectum is pulled out to the final position, the cut edge of the peritoneum is sutured to the serosa of the upper-half surface of the inner tube, forming an arch (a). This way a new pouch of Douglas is created, as shown in (b)

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

313

a

Puborectalis m.

b

Sutured puborectalis m.

A

B

C A

Fig. 12.8  The next step is to plicate the levator ani muscle. With the right and left puborectalis muscles withdrawn with Pean forceps (a), 1-0 Vicryl plication sutures

are applied between the muscles sequentially from the perineal body side. This ensures that the anus can be tightened at a deeper level as shown in (b)

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

314 Fig. 12.9  We move now to resection of the excess intestine. After the outer tube is everted into a single tube, intestinal forceps are applied to the 11:05 position and the intestine is divided between the forceps at the 12:00 position with electrocautery (arrow in a). If the excess intestine is much longer than the intestinal forceps, it can be tentatively cut to an appropriate length before actual incision. The incision is stopped 1–2 cm before reaching the peritoneal suture line, and this part of the intestine is fixed to the 12:00 position of the stump of the outer tube with a 3-0 Vicryl suture (b)

a Sutured puborectalis m. Peritoneal suture line

b

3-0 Vicryl detach

Outer tube stump Dentate line

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure Fig. 12.10 The intestinal forceps are repositioned to the 7:25 position and the intestine is divided between the forceps at the 6:00 position with electrocautery (arrow in a). The intestine is then fixed in the 6:00 position of the outer tube stump with a 3-0 Vicryl suture in the similar manner. The excess intestine opened bilaterally like strips is then transected along the anal verge with electrocautery (arrows in b)

a

b

315

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

316

a

b

Dissected edge of inner tube

Outer tube stump

Fig. 12.11  The dissected edge of the intestine (inner tube) is fixed to the outer tube stump with 16–20 sutures (a) and sagittal cross section in (b). Because the anasto-

mosis is not subject to excessive tension and is well vascularized, anastomotic leak is very unlikely to occur after this operation

12  Surgical Repair of Rectal Prolapse: The Altemeier Procedure

317

a

b

Sutured peritoneum (new pouch of Douglas)

New anus tightened by plicated puborectalis m.

Fig. 12.12  After completing circumferential suturing, the anastomosis is introverted to reduce the prolapse. The index finger is inserted to assess for tension (a). Compared with Fig.  12.1b showing a prolapsed rectum, (b) here

shows a shortened intestine with a “new” anus tightened by the plicated puborectalis muscle behind the relaxed external anal sphincter

Hemorrhoidectomy

Abstract

Organ-specific expertise is being increasingly emphasized within the already narrow field of gastrointestinal surgery. This trend is becoming more apparent outside of university hospitals too. However, given the universality of the anatomy on which surgery is based, I feel it a huge waste to limit the surgeon’s skill to particular organs all in the name of specialty. As gastrointestinal surgeons, we should bear in mind that the continuity of membranes and the

13

major principles of total mesenteric resection are applicable to all organs as a whole. Although simple, hemorrhoidectomy is a gastrointestinal surgical procedure that self-­ proclaimed specialists are encouraged to master. It takes only about 10  min to remove 1 hemorrhoid and just 30 min for 3 hemorrhoids. Keywords

Hemorrhoidectomy · Surgical anatomy Organ-specific expertise

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_13

319

13 Hemorrhoidectomy

320 Fig. 13.1 Lumbar anesthesia is administered with the patient in the sitting position. After 3–5 min, the patient is repositioned to the jack-knife position, with the gluteal region exposed to the right and left and fixed with adhesive plasters. Because patients with hemorrhoids tend to have anal stenosis, it is advisable to insert the index fingers of both hands into the anus to adequately relax the muscles of the anal sphincter before starting the operation

Fig. 13.2 Internal hemorrhoids commonly occur at the 3, 7, and 11 o’clock positions, although the pattern of onset varies considerably from patient to patient. First, two flat retractors are inserted into the anus to assess the overall morphology of the hemorrhoids and imagine the final picture. To prevent postoperative stenosis, up to 3 (at very most 4) mucosal resections should be made even for a nearly circumferentially developed hemorrhoid. The largest hemorrhoid should be resected first. The mucosa near the dentate line is grasped with Pean forceps

Internal hemorrhoid Dentate line

13 Hemorrhoidectomy

321

Fig. 13.3  With the hemorrhoid lifted up with the forceps, a V-shaped skin incision is made on the anal verge with a scalpel (arrow)

Fig. 13.4  The apex of the V-shaped incision is grasped with another pair of Pean forceps. The left index finger is placed on the medial side of the hemorrhoid, and then the two pairs of forceps are pulled slightly upward which serves to lift the darkened hemorrhoidal varix. The loose connective tissue between the varix and anal wall is dissected using an inactivated electrocautery device as a spatula, with care taken not to rupture the varix. At this point, the hemorrhoid can be lifted quite a lot. The remaining task is to dissect streaks of residual connective tissue with activated electrocautery. The circular muscle fibers of the internal anal sphincter can be seen on the anal wall side

Int. anal sphincter

Internal hemorrhoid (varix)

13 Hemorrhoidectomy

322 Hemorrhoidal a. (br. of superior rectal a.)

Fig. 13.5  After the dissection from the lateral side has proceeded to a considerable point, we can then move on to dissection of the connective tissue on both sides of the hemorrhoid. After pulling the hemorrhoid laterally and palpating the hemorrhoid artery (a branch of the superior rectal artery), a mucosal incision is made on both sides of

the hemorrhoid. To prevent postoperative anal stenosis, we should minimize the width of the mucosal incision. Remember that the goal of hemorrhoidectomy is to remove varices formed under the mucosa, and mucosal resection offers only a breakthrough toward achieving this goal

13 Hemorrhoidectomy

323

Fig. 13.6 The submucosal layer is entered from the mucosal incision line to completely remove the hemorrhoidal varix by scraping it off. This is done in the same way as described in Fig. 13.4, by activating the electrocautery device or using it as a spatula

Int. anal sphincter

Fig. 13.7  Now that the hemorrhoidal varix has been completely detached from the internal anal sphincter and the bilateral submucosal layers, the only connective tissue remaining is a cord-like structure containing the hemorrhoidal artery. The cord-like structure is ligated by a piercing with a 3-0 Vicryl suture

324 Fig. 13.8 After applying a clamp distal to the ligation and resecting the hemorrhoid, another 3-0 Vicryl suture is applied to make a double ligation. One of the two suture threads is left uncut so that we can use it as a stay suture for the next mucosal suture

Fig. 13.9  The mucosal defect formed by resection can either be left untreated as an open wound or suture-closed to achieve hemostasis at the mucosal stump and promote clean wound healing. A running 3-0 Vicryl suture is placed. The first ligation suture and stay suture are further tied to invaginate the stump

13 Hemorrhoidectomy

13 Hemorrhoidectomy Fig. 13.10 The mucosal suture should not exceed the dentate line. To prevent the formation of dead space, we should leave the skin incision unsutured as an open wound for drainage

Fig. 13.11  The procedure described above is performed for all hemorrhoids, typically 3. The operation is completed after confirming the absence of bleeding and the completeness of the mucosal sutures

325

Right Hemihepatectomy

Abstract

Compared to segmentectomy or subsegmentectomy of the liver, which must be done systematically while approximating the course of blood vessels and bile ducts embedded in the nontransplant organ, right hemihepatectomy is a simpler technique where the right half of the liver is cut off along the RexCantlie line. After the vessels on the right have been divided in the portal region, the

14

only thing we need to be concerned with is handling the veins: we need to be careful when handling these small thin hepatic veins in the somewhat chunky liver. The standard operation time is 4 h. Keywords

Right Hemihepatectomy · Rex-Cantlie line Glissonean pedicle · Couinaud subsegment classification

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_14

327

14  Right Hemihepatectomy

328 Fig. 14.1  The surgeon stands on the right side of the patient and makes a J-shaped incision in the upper abdomen. An incision curved toward the umbilicus provides a better view of the operative field in the portal region compared with an incision along the right costal arch

Fig. 14.2  A Kent retractor is applied to spread the wound in three directions. If necessary, we can use an Octopus retractor to pull the right edge of the wound laterally

Octopus retractor

14  Right Hemihepatectomy

329

Fig. 14.3  Adhesions between the gallbladder or underside of the liver and the transverse colon are dissected with electrocautery

Fig. 14.4  The transition line from the retroperitoneum covering the anterior surface of the kidney to the liver capsule (hepatorenal ligament) is divided with electrocautery (arrow). It is advisable to have the first assistant insert curved dissection forceps under the ligament to guide the dissection. When the underside of the liver is fully mobilized, a surgical laparotomy sponge is placed over the colon and the anterior aspect of the stomach

Hepatorenal lig. IVC

14  Right Hemihepatectomy

330

a

Ligamentum teres

b Falciform lig.

R coronary lig.

Fig. 14.5  The next step is to mobilize the right lobe. The ligamentum teres is ligated with a 1-0 silk suture and then divided (a). The suture thread on the liver side is kept long enough to be pulled later and grasped with Pean forceps. The falciform ligament is then divided along its attachment to the

liver (b). The falciform ligament consists of two layers of peritoneum, which are fused into a single membrane at a certain distance from the round ligament. This ligament divides into a V-shape when approaching the inferior vena cava (IVC), continuing as the right and left coronary ligaments

14  Right Hemihepatectomy

331 Falciform lig.

R coronary lig.

Fig. 14.6  As the dissection of the falciform ligament passes the apex of the V-shape, a small hole opens up, through which air enters, causing distention of cotton-like loose connective tissue. This loose connective tissue contains the root of the three hepatic veins. Curved dissection forceps are inserted through this hole, along the attach-

ment of the right coronary ligament to guide dissection with electrocautery (arrow). Do not open the forceps too wide but insert while trying to scoop the thin peritoneum only because the right hepatic vein may be attached to the right coronary ligament

Mid. hepatic v.

R hepatic v.

Fig. 14.7  The connective tissue surrounding the right and middle hepatic veins is roughly dissected with Metzenbaum scissors or dissectors. At this point, the

approximate locations of the entrance of the veins into the liver parenchyma and the bifurcation of the veins should be determined

14  Right Hemihepatectomy

332

a

R coronary lig.

Hepatorenal lig. R triangular lig.

b

L triangular lig.

Bare area

L coronary lig.

Fig. 14.8 The right coronary ligament (①) and the subsequent right triangular ligament (②) are divided along their attachment to the liver (a). In this operative angle, it is advisable to have the first assistant insert dissection forceps to guide dissection with electrocautery, although, again, the forceps should not be opened too wide so as to avoid damaging the phrenic vessels. Once the dissection is connected to the dissection

line of the hepatorenal ligament (③) as we saw in Fig. 14.4, then two of the three sides of the bare area of the right lobe have been dissected (b). The falciform ligament forms sides ① and ③, so the hepatorenal ligament is part of it. The apical ends of the two sides are anchored to the diaphragm by the right triangular ligament (②), which is not as easy to distinguish as the left triangular ligament

14  Right Hemihepatectomy

333

Fig. 14.9  The “plane” of the bare area is detached from the surrounding structures. The plane of this triangular area is in contact with the diaphragm, the upper pole of the right kidney, and the right adrenal gland

Diaphragm

R adrenal gland

Superior pole of R kidney

Cotton glove

Fig. 14.10  When the first assistant lifts the right lobe to the left (toward them), the accompanying diaphragm is also lifted. A cotton glove should be worn on the left hand for ease of grasping and to avoid slippage. When the surgeon applies tension by pulling back the diaphragm with forceps held in the left hand, the liver capsule is spontaneously detached from the parenchyma along with thin loose thread-like connective tissue. This dissection procedure needs only slight assistance with electrocautery

held in the right hand. In the presence of liver cirrhosis, the liver capsule may be tightly adherent due to inflammation and any attempt to detach the capsule forcibly by applying tension might injure the phrenic vessels (right inferior phrenic artery and vein), causing considerable bleeding. So, we must be sure that the dissection layer is not separated from the liver capsule. In the cranial part, we must not be careless enough to damage the right hepatic vein

14  Right Hemihepatectomy

334 Fig. 14.11  After the diaphragm falls away, the right adrenal gland can be seen being pulled up by the liver. The organ can be identified by its unique ocher color. In cases of cirrhosis, because the adrenal gland may be embedded in the liver parenchyma, we should take particular care identifying the boundary when detaching the organ from the liver. It may even be safer to cut into the liver parenchyma to detach the adrenal gland from the liver

R triangular lig.

R inf. pherenic a. & v.

Bare area

R adrenal gland Sup. pole of R kidney

14  Right Hemihepatectomy

335

Inf. vena cava

R inf. hepatic v.

Fig. 14.12  While the first assistant holds up the right lobe cranially (not to the left), the surgeon continues detaching the adrenal gland this time from this angle of view. When the adrenal gland completely falls away, the wall of the IVC is exposed. If there is any damage to the adrenal gland, we can use 3-0 Vicryl sutures to achieve hemostasis, although considerable bleeding may still occur. During this procedure, we might encounter a quite thick short hepatic vein (the right inferior hepatic vein) as

it drains into the IVC. This vein should be either ligated and divided or should be clamped followed by division and closure with a 5-0 Prolene suture. Unknowingly cutting this vein may result in difficult-to-control bleeding. The right lobe is now mobilized. When a large tumor is present, it is advisable to first perform vascular dissection of the portal region to slightly reduce the volume of the right lobe before mobilizing it

14  Right Hemihepatectomy

336 Rex-Cantlie line

3 4 6

1

1 4

1

3

2

Post. segment

Ant. segment

Right lobe

Fig. 14.13  Vascular anatomy of the liver: The liver is divided into the left and right lobes by the Rex-Cantlie line, and the right lobe is further divided into the anterior and posterior segments. Although the three parts of the liver are of almost similar volume, the liver has an asymmetric shape where the vertical width tapers to the left and the horizontal width of each part tapers to the right. In the

Left lobe

figure, each rectangle represents a different segment of the liver and all rectangles have the same area, and the right posterior segment is considerably elongated vertically compared with the left lobe. This is why in posterior segmentectomy, we might find that the discolored area after dissection of the Glissonean pedicle is smaller (thinner) than we expected

14  Right Hemihepatectomy

337

Main portal arch

Transverse portion (TP)

P8

P7

P8

P2

P4b

Umbilical portion (UP)

A P P7

P3 P4a

P6

P5

P3

P5

Dorsal br.

Ventral br.

P6

Fig. 14.14  The portal vein has been drawn onto the schematic diagram from Fig.  14.13. We should take note of several points The right portal vein splits into the anterior (A) and posterior (P) segmental branches, with the diameter also split equally. In a Couinaud diagram of the liver, the anterior segmental branch further splits into the upper (P8) and lower (P5) branches [17]. However, the anterior segmental branch is more likely to divide into the ventral and dorsal branches. This seems natural in view of the horizontally elongated shape of the anterior segment. Each of the two branches further gives off the upper and lower branches. So, when this pattern is fitted to the Couinaud subsegment classification, the area supplied by the upper branches of the ventral and dorsal branches can be defined as S8 and the area supplied by the lower branches as S5. Actually, the Japanese guidelines for managing primary liver cancer also define S8 as the area cranial to the main bifurcation of the anterior segmental Glissonean pedicle and S5 as the area caudal to it, which is based on mapping from the liver surface than on the portal branching pattern The posterior segmental branch, after diverging from the anterior segmental branch, travels craniodorsally forming an arch (the main portal arch). Again, it is rather unusual that this branch splits into P6 and P7, as shown in a Couinaud diagram. Instead, the posterior segmental branch usually gives off several P6 branches before giving off P7 branches. This pattern, where the main branch trav-

els downward and then ascends while giving off branches, may be advantageous in supplying blood to the entire area of the vertically elongated posterior segment. The Japanese guidelines define the area caudal to the main bifurcation of the posterior segmental Glissonean pedicle as S6 and the area cranial to the said portion as S7, which is again a segmental classification when viewed from the liver surface The left portal vein runs transversely and, after giving off the P2 branch laterally, makes an almost right-angle turn to become the umbilical portal vein (UP). From the end of the UP, P3 arises laterally and P4 arises medially. There is usually one P2 branch and often two P3 branches. It is also common for additional small branches to arise directly from the UP between P2 and P3. P4 immediately divides into P4a coursing toward the periphery and P4b coursing proximally, although these branches often arise separately from the UP, as shown. The UP, as described in Chap. 1 on the anatomy of the stomach and surrounding structures, is an intermediate portion of the main blood supply route from the placenta to the IVC during fetal life. After birth, the umbilical vein connecting the umbilicus and the UP becomes the round ligament of the liver, while the ductus venosus (duct of Arantius) connecting the UP and the IVC becomes the ligamentum venosum, both of which are obliterated vascular remnants through which no blood flows

14  Right Hemihepatectomy

338 Mid. hepatic v. R hepatic v.

L hepatic v.

Superficial v. (R sup. hepatic v.)

Superficial v. (L sup. hepatic v.)

S4b S8

S4a

Umbilical fissure v. (L medial v.)

S5 Gallbladder

S6

R inf. hepatic v.

Fig. 14.15  Now the hepatic veins are drawn onto the figure. Of the three main hepatic veins (i.e., the right, middle, and left hepatic veins), the middle and left ones often form a common trunk. If we define the hepatic veins as those located along the boundaries of the three segments with an equal volume, we can regard the left hepatic vein as a branch of the middle hepatic vein. However, the left hepatic vein is essential for efficient venous return from the tip of the horizontally elongated left lobe, so we should regard it as an independent main hepatic vein As surgeons who will be doing hepatectomies, we need a little more detailed anatomical knowledge. Each main hepatic vein appears like the leaf of Gleichenia japonica, an evergreen fern, and it receives venous return from the areas on both sides, as shown. Also, several adjunctive veins, including the superficial veins at both ends, are present as if filling the gaps between these main hepatic veins. Of these, the umbilical fissure vein, located between the left and middle hepatic veins, ascends along the UP and, while receiving venous return from S3 and S4, converges with the left hepatic vein. This is one of the veins that we should pay attention to during lateral segmentectomy The middle hepatic vein splits into two parts at its terminal; the right vein receives venous return from the ventral part of S5 and the left vein from S4a. In the middle part, the middle hepatic vein receives two branches from

the right and left sides, with the right branch receiving venous return from S8 and the left one from S4b. The vein finally converges with the left hepatic vein and drains into the IVC. This is the basic branching pattern of the middle hepatic vein. Between the split veins at the terminal is the hepatic bed of the gallbladder. The liver parenchyma intervenes between the vein and the gallbladder but is only about 5 mm thick. We should keep this vein in mind when excising a severely inflamed gallbladder During right hemihepatectomy, veins draining to the right wall of the middle hepatic vein are encountered on the transection plane. Liver dissection proceeds along the Rex-Cantlie line from the periphery while dissecting branches from S5. Once the right wall of the main trunk is exposed, intraoperative ultrasonography is done to identify at least one or two large branches from S8 that will probably be encountered before reaching the root of the middle hepatic vein. This helps to avoid unnecessary bleeding If we think about the efficiency of venous return, the caudal part of the vertically elongated posterior segment (right segment), or S6, has the disadvantage that it is quite far from the root of the right hepatic vein. For this reason, a large branch directly draining into the IVC, which is located nearby, can often be identified as the right inferior hepatic vein. In right hemihepatectomy, this vein is often encountered during the procedure to detach the adrenal gland and must be dissected with care

14  Right Hemihepatectomy

339

2

8 7

4b

8

3

4a 5

5

6

Fig. 14.16  Finally, we superimpose the portal and hepatic veins. The numbers correspond to those of subsegments defined by Couinaud. The hepatic vein branches correspond to each portal branch

340

Fig. 14.17  We move on in the operation to manipulation of the hilar region. The portal region can be dealt with either by en bloc transection of the Glissonean pedicle or by individual isolation, ligation, and division of the hepatic artery, portal vein, and bile duct. Because the main objective of this book is to illustrate the local anatomy, we will focus on the latter technique hereon in. The first assistant scoops the underside of S4 cranially with an intestinal spatula while pulling up the round ligament to secure the operative field. At the same time, the surgeon places the

14  Right Hemihepatectomy

left index and middle fingers on both sides of the hepatoduodenal ligament and pulls the pyloric region and duodenum caudally to spread the ligament wide. The procedure begins with cholecystectomy. A peritoneal incision on the hepatoduodenal ligament should be made along a large circle (arrows) for ease of the subsequent manipulation of the right Glissonean vessels. (In routine cholecystectomy, a sharp-angled V-shaped incision with the cystic duct as the apex should be made)

14  Right Hemihepatectomy

341 Cystic a. R hepatic a.

Mid. hepatic a. Common hepatic duct

Cystic duct

Fig. 14.18  The fat tissue in the triangle of Calot is scraped up toward the gallbladder with Cooper scissors to expose the cystic duct and the cystic artery embedded there. The duct and artery are ligated and divided separately. At this point, the wall of the right hepatic artery from which the cystic artery branches is usually partially exposed and seen to be pulsatile. The gallbladder is then

detached from the hepatic bed and excised. Here again, it is advisable to excise the gallbladder with connective tissue remaining on the gallbladder side to make sure that no excess tissue remains on the hepatic bed side, unlike in routine cholecystectomy, so that subsequent vascular dissection and parenchymal dissection are quicker

14  Right Hemihepatectomy

342 Liver bed

Mesocyst

Cystic duct (ligated)

Fig. 14.19  Residual fat tissue may be present in the triangle of Calot after cholecystectomy. This is the “mesocyst” intervening between the gallbladder and the

extrahepatic Glissonean pedicle. This should be scooped with dissecting forceps and divided so that the right hepatic artery can be easily identified

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343 Ant. segmental br. of hepatic duct

R hepatic a.

5

8 Mid. hepatic a.

5

6 L hepatic a. 8 6

7

7

Cystic a.

Post. segmental br. of hepatic duct

Fig. 14.20  Note that when viewed from the operative angle for portal manipulation, the branching pattern of the Glissonean vessels appears differently from that viewed from the front in Fig.  14.16. More specifically, the S5 branches in the anteroinferior segment run upward, while the S8 branches in the anterosuperior segment run downward behind the posterior segmental branches. The main portal arch of the posterior segmental branch (S7 posterosuperior segmental branch) curves downward, while the

S6 posteroinferior segmental branch courses upward. The right hepatic artery courses almost along the portal vein on its ventral side. The right hepatic duct usually courses cranial to the portal vein, so it can appear gradually to be hidden behind the portal vein when viewed from this angle. In rare cases though, the posterior segmental branch of the hepatic duct crosses in front of the anterior segmental branch of the portal vein or branches from the left hepatic duct, so we should keep these variations in mind

14  Right Hemihepatectomy

344 R portal v.

Common hepatic duct

Cystic duct (ligated)

Fig. 14.21  The connective tissue around the right hepatic artery is scooped with right-angled dissecting forceps and dissected with electrocautery to expose the entire circum-

ference of the arterial wall. The artery is scooped with the forceps and then ligated and divided

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345

Paracaval portion of caudate lobe

R hepatic a. (cut)

* Caudate br. of R portal v.

R hepatic a. (root)

Fig. 14.22 When the right hepatic artery has been divided, we can see the dark blue-colored anterior wall of the right portal vein below. Using two dissectors is effective for isolating the portal vein. First, the concave surface of the bifurcation of the right and left portal veins is accessed from the upper border. Then, the right portal vein is lifted from the parenchyma of the caudate lobe. By

slightly lifting the portal vein with the dissector held by the left hand to secure the operative field and then pushing the liver parenchyma with the dissector held by the right hand, we can easily—but gradually—detach the portal vein from the parenchyma. Look out for a small branch (asterisk) arising from the dorsal side of the right portal vein and draining into the paracaval portion of the caudate lobe

14  Right Hemihepatectomy

346 R portal v.

Caudate process

Caudate br. of R portal v.

Fig. 14.23  Then, the same procedure is performed from the lower border of the liver. One to two small branches entering the caudate process are identified and then ligated and divided. Although ligation of the hepatic side of the portal vein may be performed at this level, there is a risk that the ligation suture could fall off during other proce-

dures due to the large diameter of the portal vein. Dissecting the anterior and posterior segmental branches separately is not so time- or labor-consuming, so we should do this, especially when it might be difficult to secure an adequate margin for closing the stump of the right portal vein

14  Right Hemihepatectomy

347 Ant. branch

Caudate br. (ligated)

Post. branch

Fig. 14.24  The bifurcation of the anterior and posterior segmental branches is exposed using two dissectors and is then detached from the liver parenchyma

348

Fig. 14.25  Each branch is scooped with right-angled dissecting forceps guided by the left index finger and divided after double-ligation (one by piercing suture). If we find that the tip of the forceps does not penetrate the connective tissue smoothly, do not push it forcibly and instead

14  Right Hemihepatectomy

just try again after making a path with a dissector. There is still a long way until we complete the operation, so the stump on the resection side should also be closed by reliable piercing ligation to make sure that the ligation suture will not come off during other procedures

14  Right Hemihepatectomy

349 Ant. br. of PV (root)

Ant. br. of PV (ligated)

R hepatic a. (ligated)

R hepatic a. (root)

Post. br. of PV (ligated)

PV (L border)

Caudate process IVC Post. br. of PV (root)

Fig. 14.26  Once the right portal vein has been transected, the parenchyma of the caudate lobe can be seen below. The parenchyma is thinnest in this concave area, with the caudate process on the right and the lobule of

Spiegel on the left, as well as the Glissonean vessels of the right portal region on the upper side and the IVC on the bottom side. So, it is advisable to start parenchymal dissection from this area (see Fig. 14.41)

14  Right Hemihepatectomy

350 Rex-Cantlie line

Transection line of liver parenchyma

Fig. 14.27  Because the right hepatic artery and right portal vein have been transected, the right lobe is discolored to a dark red, bordered by the Rex-Cantlie line. An

imaginary transection line is set 5 mm to the right of the line and marked with electrocautery

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351

Bifurcation of R and L hepatic ducts

Fig. 14.28  Finally, the hepatic duct located deepest behind the right Glissonean pedicle has to be dissected. Compared with the extrahepatic bile duct, whose wall is smooth and can be easily isolated, the hepatic duct is much more fibrous and difficult to isolate. The bifurcation of the right and left hepatic ducts is covered by a thick Glissonean capsular membrane of the hilar plate and is

firmly adherent to and embedded within the S4 parenchyma. Accessing this part is the first step toward identifying the hepatic duct. The connective tissue is dissected extensively so that even the liver parenchyma can be dissected. The dissection also proceeds from the lower border

14  Right Hemihepatectomy

352

R hepatic duct

Fig. 14.29  Even after a considerable amount of dissection, we will not get the forceps to pass through the connective tissue around the hepatic duct. Do not be tempted to push because you could end up with bile leakage postoperatively. Instead explore other options to pass the forceps through smoothly. Once you have managed this, you will feel so relieved that you will find you can now relax

your shoulders. The right hepatic duct is ligated and divided to complete portal manipulation. If isolating and identifying the hepatic duct is difficult, it is safer to proceed with parenchymal dissection first and then return to hepatic duct isolation after the dissection has reached the hilar plate

14  Right Hemihepatectomy

353 Planes to which right and left lobes attach = dissection plane along Rex-Cantlie line

R hepatic v.

Mid. hepatic v.

A * L R Lobule of Spiegel B Paracaval portion

IVC

Caudate process

Fig. 14.30  Before moving on to the next step of dissecting the short hepatic vein, we would like to review the anatomy of the caudate lobe. The caudate lobe is usually divided into three parts: lobule of Spiegel, paracaval portion, and caudate process. The caudate lobe is the only hepatic lobe in contact with the IVC and which provides planes to which the right and left lobes attach. The plane cut obliquely and laterally from a line connecting the root of the middle hepatic vein (A) and the bifurcation of the anterior and pos-

terior segmental branches from the Glissonean pedicle (B), plane Ⓡ, is the right border of the lobe and is where the right lobe attaches. The trapezoidal area bounded by the duct of Arantius (asterisk) and the horizontal part of the Glissonean pedicle, plane Ⓛ, is the plane to which the left lobe attaches. The Glissonean vessels enter the caudate lobe immediately after splitting into the right and left primary branches, and the venous blood directly returns into the IVC through the short hepatic veins

14  Right Hemihepatectomy

354 L hepatic v.

Mid. hepatic v. R inf. phrenic v.

Liver bed

R hepatic v. *

Ligamentum venae cavae

*

Membranous connective tissue

* Lobule of Spiegel

R inf. hepatic v. IVC

Fig. 14.31  We move next to dissection of the short hepatic veins. These veins can be divided into two groups: those draining into the anterior aspect of the IVC (asterisk) and those draining into the right lateral aspect of the IVC. The latter are embedded in the membranous connective tissue that anchors the liver to the right border of the IVC.  First, the former are dissected via a caudal approach and then the latter via a right lateral approach.

When the liver is transected along the Rex-Cantlie line, the resulting cross section is in the shape of a wedge with a short base. Surprisingly, when we look at a resected specimen of the liver, the base (i.e., the attachment of the liver to the IVC) is actually only about 5  cm long. Dissecting the short hepatic veins is the most thrilling part of doing a right hemihepatectomy and can be referred to as “the 5-cm-of-fear step”

14  Right Hemihepatectomy

355

Caudate process

R inf. hepatic v. (ligated) Inf. vena cava

Fig. 14.32  The short hepatic veins draining into the anterior aspect of the IVC are dissected first. After repositioning the liver to allow for portal manipulation, the interface between the caudate process and the anterior aspect of the IVC is divided with two dissectors. The connective tissue in this area is loose and contains two to three veins measuring 2–3 mm in diameter. These vessels are sequentially

scooped with right-angled dissecting forceps and ligated and divided. After this 5-cm-of-fear step, the root of the middle hepatic vein can be identified. This liver position provides a good view of the operative field and allows the first assistant and other assistants to clearly see what the surgeon is doing. Completely dissecting these veins will make it easier to perform the subsequent procedure

14  Right Hemihepatectomy

356

Bare area

Lig. venae cavae Short hepatic v.

Inf. vena cava

Fig. 14.33  The short hepatic veins draining into the right lateral aspect of the IVC are dissected next. The first assistant displaces the right lobe to the left (toward them). This stretches membranous connective tissue between the IVC and the right lobe. This connective tissue contains a thick short hepatic vein. Curved dissecting forceps are inserted behind the connective tissue along the liver parenchyma, and the vein is scooped together with the connective tissue and ligated and divided. This membranous connective tis-

sue thickens slightly as it approaches the bifurcation of the hepatic veins (see Fig.  14.31), turns around the dorsal aspect of the IVC, and attaches to lobule of Spiegel. This connective tissue is referred to as the ligamentum venae cavae, and it anchors the IVC to the inferior vena caval fossa. At this point, the dissection proceeds immediately before reaching the ligament. Now, all three sides of the bare area of the right lobe (see Fig.  14.8b) have been dissected

14  Right Hemihepatectomy

a

Lobe hooked at edge of wound

357

b Space formed in cavity

Short hepatic v. fully stretched

R adrenal gland R kidney

Ao

Bad displacement

Fig. 14.34  The success of this procedure depends on whether the surgeon and the first assistant can share a good view of the operative field. If the first assistant simply pulls the right lobe, the liver then obscures the operative field and the short hepatic vein is not fully stretched (a). If the right lobe is pulled after the left lobe has been firmly pushed into the space formed in the left abdominal

IVC

Good displacement

cavity (arrow), the posterior aspect of the liver rises upright, providing a good operative field of view (b). Also, the IVC is deformed by the displaced right lobe into a “comma” shape and has become so thin that it may be ruptured by the dissecting forceps unless inserted along the liver parenchyma

14  Right Hemihepatectomy

358

Mid. hepatic v.

R hepatic v.

Fig. 14.35  Dissection of the right hepatic vein: After repositioning the liver to its original position, the medial border of the root of the right hepatic vein is exposed using dissectors. The dissection should be performed as distally as possible so that any possible rupture can be

repaired easily. However, because the dome-like bulging of the liver parenchyma interferes with the procedure, we should advance the dissection as if digging into the parenchyma. A small area of the parenchyma around the bifurcation can be dissected with electrocautery as shown

14  Right Hemihepatectomy

359

Lig. venae cavae

Short hepatic v. (ligated)

R inf. hepatic v. (ligated)

Fig. 14.36  The right lobe is again displaced to the left. The ligamentum venae cavae is then divided lateral to the right hepatic vein. This ligament might also contain a short hepatic vein and, if encountered, it should be clamped with a hemostat inserted along the liver, divided, and suture-closed with a 5-0 Prolene suture. The IVC is

slightly thinned around this ligament and deformed by displacement of the right lobe. The division of the ligament allows the right lobe to be lifted further, exposing the lateral border of the right hepatic vein. At times, the parenchyma may extend into the ligament

14  Right Hemihepatectomy

360

a

R hepatic v.

Lig. venae cavae (sutured)

b

Fig. 14.37  Right-­angled dissecting forceps are inserted via a recess formed between the anterior surface of the IVC and the root of the right hepatic vein and then advanced carefully along the liver through the connective

tissue (a). If the tip of the forceps does not pass through the connective tissue smoothly, do not push it but try again after making a path with a dissector. Inserting the forceps from the caudal side can achieve penetration smoothly (b)

14  Right Hemihepatectomy

361

b

a

Safe

Fig. 14.38  The root of the right hepatic vein has been considerably thinned by the comma-like deformation of the IVC and its constriction with the right hepatic vein at the apex. Because of this, the vein can easily be ruptured

Fig. 14.39  Vascular tape is passed around the encircled right hepatic vein and grasped with mosquito forceps. The right hepatic vein may be divided at this point if it has a sufficiently long neck, although parenchymal dissection is usually started without dividing the vein. Sometimes, even encircling the vein is difficult. In such cases, we can start parenchymal dissection without encircling the vein

Unsafe

by the tip of the right-angled dissecting forceps if facing outward (b). So, we should insert the forceps along the liver (a)

362

Fig. 14.40  As a guide for determining direction during parenchymal dissection, a Penrose drain is passed under the right hepatic vein, pulled out between the IVC and the caudate process, and grasped with Pean forceps. Before

14  Right Hemihepatectomy

starting the dissection, intraoperative echography is repeated to determine the course of the hepatic veins crossing the Rex-Cantlie line

14  Right Hemihepatectomy Fig. 14.41  The parenchymal dissection should be started from the interface between the caudate process and lobule of Spiegel because this is where the parenchyma is the thinnest. The dissection can be done in one stroke using the preplaced Penrose drain as a pillow, although efforts should be made to minimize the area dissected, at least by avoiding swerving to the left

Fig. 14.42  Parenchymal dissection is performed along the line previously marked with electrocautery. The first incision can be made with electrocautery because there are no major cord-like structures up to a depth of about 5 mm

363

14  Right Hemihepatectomy

364

First assistant’s right hand (saline-coupled bipolar electrocautery device)

First assistant’s left hand

Second assistant’s right hand

Surgeon’s left hand

Fig. 14.43  Various devices and techniques can be used for parenchymal dissection, but here we look at using a Cavitron Ultrasonic Surgical Aspirator (CUSA) and a saline-coupled bipolar electrocautery device. Traction sutures are placed at the edge of the planned transection line. The first assistant holds the suture thread on the rem-

Surgeon’s right hand holding a CUSA

nant side, while the surgeon holds the suture thread on the resection side to adjust the size of the dissection plane. The surgeon is in charge of manipulating the CUSA, the first assistant is in charge of saline-coupled bipolar electrocautery, and the second assistant is in charge of the suction tube

14  Right Hemihepatectomy

365

a

V8

*

V4b

V4a

V5

b

V5

Dissected caudate process

Fig. 14.44  Most of the vessels appearing on the dissection plane along the Rex-Cantlie line are veins. Dissecting the thin parenchyma at the liver floor 5–6 cm reaches the point where the middle hepatic vein (MHV) splits into the right and left branches (asterisk in a). Of these branches, the branch that receives venous return from S5 is scooped

with right-angled dissecting forceps (b) and is ligated and divided. The dissection then advances proximally along the right side of the MHV while dissecting small branches along the venous wall. At least one or two more large branches from S8 are encountered before reaching the root of the MHV

14  Right Hemihepatectomy

366 Mid. hepatic v.

V5 (ligated)

Clip applier

Fig. 14.45 Venous branches ≥2–3  mm in diameter should be scooped with right-angled dissecting forceps, ligated on the remnant side, clipped on the resection side, and divided with Metzenbaum scissors. It is advisable to leave the clipping clamp unlocked until the dissection is complete. Thin veins can be cauterized and divided with

bipolar electrocautery. The thin thread- and cord-like structures appearing on the dissection plane are mostly bile ducts. These should also be carefully cauterized and divided with bipolar electrocautery. Be careful here to avoid causing bile leakage postoperatively

14  Right Hemihepatectomy

367 Mid. hepatic v.

V8 (ligated)

V5 (ligated)

R hepatic v.

Fig. 14.46  After advancing the parenchymal dissection proximally and approaching the bifurcation of the right and middle hepatic veins, the parenchyma in that area is carefully divided by fragmentation and aspiration with the

CUSA in the direction toward the vascular tape placed on the right hepatic vein. The right hepatic vein is clamped with a hemostat and the specimen is excised. The stump is then closed with a 5-0 Prolene suture

368

14  Right Hemihepatectomy

Dissection plane of paracaval portion of caudate lobe

Sutured R hepatic v.

Dissection plane of caudate process

Fig. 14.47  After excising the specimen, the abdominal cavity is washed and hemostasis of the dissection plane is achieved using a 4-0 PDS suture or by electrocautery for fine bleeding points. We should confirm the absence of bile leakage by applying new gauze on the dissection

plane. After washing the abdominal cavity again, an 8-mm duple drain is placed in the right subphrenic region and the operation is completed by closing the abdominal wall, suturing in three layers

Left Lateral Sectionectomy

Abstract

During fetal life, blood from the placenta flows through the umbilical vein and ductus venosus and drains into the inferior vena cava of the fetus. After birth, the umbilical vein is obliterated, except for a remnant that becomes the umbilical portal vein and is replaced by the round ligament of the liver, while the ductus venosus also closes and becomes the ligamentum venosum. In left lateral sectionectomy, the part of the liver to the left of these old

15

structures is cut off, and here the ligamentum venosum serves as a good landmark for determining the transection line. The duct of Arantius, which surgeons often use as a reference, is the obliterated ligamentum venosum and is occasionally mentioned in this chapter. The standard operation time is 2 h and 30 min. Keywords

Umbilical vein · Ductus venosus · Left lateral sectionectomy · Duct of Arantius

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_15

369

370

Fig. 15.1  The surgeon stands on the right side of the patient and makes an upper abdominal midline incision extending from the xiphoid process to the umbilicus to open the abdomen to the left of the round ligament of the liver Fig. 15.2  A wound retractor and a left rib retractor are applied to secure the operative field. A surgical laparotomy sponge is placed over the stomach, spleen, and transverse colon

15  Left Lateral Sectionectomy

15  Left Lateral Sectionectomy

371 Ant. layer of L coronary lig.

IVC Falciform lig.

Post. layer of L coronary lig.

L triangular lig.

Ligamentum teres

Fig. 15.3  The procedure begins with mobilization of the lateral segment and is performed in the following order: ➊ dividing the round ligament, ➋ dividing the falciform ligament, ➌ dividing the left triangular liga-

ment, ➍ dividing the anterior layer of the left coronary ligament, ➎ dividing the posterior layer of the left coronary ligament, and ➏ dividing the attachment of the lesser omentum to the liver

15  Left Lateral Sectionectomy

372

Falciform lig.

Ligamentum teres

Fig. 15.4  The round ligament is ligated and divided at a point closer to the abdominal wall side. The suture thread on the liver side is kept long enough to allow for later traction and is grasped with Pean forceps

15  Left Lateral Sectionectomy

373 L coronary lig.

Falciform lig.

Fig. 15.5  The falciform ligament is divided along its attachment to the diaphragm with electrocautery. The falciform ligament is kept attached to the liver so that it can be used as a “lid” to cover the dissection plane of the liver

afterward. The dissection proceeds up to the point where the ligament divides into a V-shape to become the right and left coronary ligaments

15  Left Lateral Sectionectomy

374 L coronary lig.

L triangular lig.

Fig. 15.6  With the lateral segment pulled caudally, the left triangular ligament is divided with electrocautery. Because the triangular ligament is formed by fusion of the anterior and posterior layers of the coronary ligament,

dividing this ligament about 3 cm medially from the tip of the lateral segment causes the coronary ligament to split into the anterior and posterior layers, forming an opening

15  Left Lateral Sectionectomy

375

L triangular lig. (divided)

Fig. 15.7  The anterior layer of the left coronary ligament is divided with electrocautery while being scooped with dissection forceps. Our dissection line should approach

the liver parenchyma gradually to avoid damaging the phrenic vessels

15  Left Lateral Sectionectomy

376 Mid. hepatic v.

L hepatic v.

R coronary lig.

Fig. 15.8  The connective tissue surrounding the left and middle hepatic veins are roughly dissected with Metzenbaum scissors. These two veins often form a com-

mon trunk at their root. Cutting the right coronary ligament slightly may make it easier to identify the hepatic veins

15  Left Lateral Sectionectomy

377 *L sup. hepatic v.

Post. layer of L coronary lig.

L hepatic v.

Fig. 15.9  The posterior layer of the left coronary ligament is divided with electrocautery (arrow). During this procedure, the left hepatic vein or a superficial vein (the left superior hepatic vein, asterisk) appears as it courses rather transversely as shown, and we need to be careful not to

damage it by moving the electrocautery device too much. It is safer to switch from electrocautery to Metzenbaum scissors when the dissection approaches the root of the left hepatic vein. The left superior hepatic vein may independently converge with the inferior vena cava (IVC)

15  Left Lateral Sectionectomy

378 L hepatic v.

Lesser omentum

Fig. 15.10  After the lateral segment is everted to the right, right-angled dissection forceps are inserted downward from the cut edge of the posterior layer of the coronary ligament (arrow) to scoop up the peritoneum and divide it with electrocautery. This peritoneum covers the

right crus of the diaphragm, which forms the esophageal hiatus, and continues as the lesser omentum. Repeating this procedure twice or more allows the tip of the forceps to reach the omental bursa

15  Left Lateral Sectionectomy

379 R crus

Lobule of Spiegel within caudate lobe

IVC Duct of Arantius

Ligamentum teres

Transverse portion of L portal v.

Fig. 15.11  After opening the omental bursa, the lobule of Spiegel within the caudate lobe makes its appearance. In the groove between this part and the lateral segment is the duct of Arantius, which used to be a major blood vessel during fetal life that connected the umbilical portal vein and the IVC but is now a cord that is attached to the lesser omentum. It is rather surprising that the attachment of the

lesser omentum to the liver, which is not much considered during gastrectomy, lies longitudinally (not horizontally) like this. As shown, the lesser omentum is divided along the duct of Arantius up to the vicinity of the hepatoduodenal ligament (arrow). If the left accessory hepatic artery arising from the left gastric artery is encountered, ligate and divide it

15  Left Lateral Sectionectomy

380 Fig. 15.12  We move on now to dissection of the Glissonean vessels. The suture thread applied to the round ligament is pulled cranially but slightly to the right to cause the lateral segment to stand upright. If the liver parenchyma forms a bridge overlying the umbilical portal vein, scoop the bridge with dissection forceps at once and divide with electrocautery

a

b Wrong shape

Correct shape

Fig. 15.13  The lateral segment of the liver is generally thought to have a pyramidal shape (a), but it is actually flat-­ shaped (b), with its longitudinal cross section not triangular-shaped but rather spindle- or comma-shaped

15  Left Lateral Sectionectomy

381

a

b 8

8

7

2

4b

3 7

6 4a

6

5 5

c

d

5

4a

5 3

6 8

4b

2

6 8 7 7

Fig. 15.14  When the liver is in its natural position as seen on abdominal opening (a), the cranial part is S2 and the caudal part is S3 (b). But when the round ligament is pulled up and the lateral segment rises upward (c), then

the upper part is S3 and the lower part is S2 (d). This follows the same logic as the liver becoming upside down when repositioned for portal manipulation during right lobectomy (see Fig. 14.20)

15  Left Lateral Sectionectomy

382 Ligamentum teres

Cut edge of lesser omentum

Lobule of Spiegel within caudate lobe

Fig. 15.15  In front of the umbilical portal vein, right-­ the peritoneum (arrow) and divide it with electrocautery. angled dissection forceps are inserted upward from the The dissection line should ascend along the left margin of preformed cut edge of the lesser omentum to scoop just the round ligament

15  Left Lateral Sectionectomy

Fig. 15.16  Opening the round ligament exposes fat and loose connective tissue, in which the portal vein, artery, and bile duct are embedded. As the connective tissue is peeled off laterally with a gauze ball, many small branches

383

leading to the left lateral segment are exposed. The forceps are switched to Metzenbaum scissors and the connective tissue is dissected carefully to roughly expose the branches

15  Left Lateral Sectionectomy

384 P3

P4a

A3

A4a from mid. hepatic a.

Mid. hepatic a.

Small br. entering from UP to lat. segment

UP

TP

A4b from L hepatic a.

P2

Common hepatic duct

A2

L hepatic a.

Fig. 15.17  When looking at these branches more closely, the transverse portal vein (TP) gives off the P2 branch from the lateral side of the corner of the curve before it becomes the umbilical part (UP) and the main P3 branch arises from the end of the UP.  There is usually one P2 branch and often two P3 branches. Between P2 and P3 are several small branches about 1 mm in diameter, in addition to the main branch. It might be surprising to see so many branches because they are rarely visualized by extracorporeal ultrasonography Although there are many variations to the course of the left hepatic artery, it commonly travels to the upper left

while crossing in front of the UP and gives off the A2 branch. From there, the A3 branch dives under (or crosses) the P2, ascends along the left border of the UP, and enters the liver parenchyma along with the main P3 branch. The middle hepatic artery supplying S4 can either arise as an independent branch outside the liver or arise from the left hepatic artery while ascending along the left border of the UP and passing behind the UP before entering S4, or it can be a mixture of the two patterns as shown. So, dissecting the left hepatic artery in front of the UP may result in sacrificing A4. The bile duct is at the deepest level and cannot be identified on opening the round ligament

15  Left Lateral Sectionectomy Fig. 15.18 Portal branches are then dissected. In the order of encounter during dissection from the surface, branches are sequentially scooped up with right-angled forceps, ligated on the proximal side, clipped on the resection side, and divided with Metzenbaum scissors

385

Small portal br.

Main P3 br.

Main P2 br.

Fig. 15.19  The main branches are ligated on both the proximal and resection sides with a 3-0 Vicryl suture and then divided. Accompanying arterial branches are also ligated and divided together with veins. To avoid damaging small portal branches that may be present behind the main branches, adequately expose these main branches with dissectors or other instruments before scooping with forceps. Because the A4 branch, which must be preserved, may arise from the artery ascending along the left border of the UP (Fig. 15.17), dissect the branch only after confirming its distribution to the lateral segment

P3 + A3

15  Left Lateral Sectionectomy

386 Fig. 15.20  The bile duct has a fibrous pattern/structure and cannot be identified easily. The connective tissue is peeled off laterally with a gauze ball to expose the bifurcation of the B3 and B2 (a). Then, dissection forceps are inserted along the liver parenchyma to scoop up each duct close to the bifurcation and then ligate/divide them (b). The ducts can be ligated en bloc before the bifurcation if the resulting ligated bundle is not too thick

P3 +A3 (ligated on proximal side)

a

B3

B2

b

B3

P2 + A2 (ligated on resection side)

15  Left Lateral Sectionectomy Fig. 15.21  Once the Glissonean vessels are dissected, the lateral segment is quite mobile (a). The remaining liver parenchyma is thinner than often expected, which again makes us appreciate the flat shape of the lateral segment. The parenchyma is only about 1.5 cm thick in a resected specimen (b)

387

a

P3 + A3 (ligated)

B3 (ligated)

P2 + A2 (ligated)

B2 (ligated)

b

1.5 cm

L hepatic v.

15  Left Lateral Sectionectomy

388 L hepatic v.

Fig. 15.22  Dissection of the left hepatic vein: With the lateral segment everted to the right, the connective tissue around the lateroposterior aspect of the left hepatic vein is roughly excised with dissectors

15  Left Lateral Sectionectomy

Fig. 15.23  Then, the lateral segment is retracted cranially to the extent that it attaches tightly to the diaphragm. After dissecting the connective tissue around the medio-

389

posterior aspect of the left hepatic vein, the convergence of the duct of Arantius can be identified

390

Fig. 15.24  The duct of Arantius is ligated and divided close to the root of the left hepatic vein. Although dissecting this duct is not essential in left lateral sectionectomy,

15  Left Lateral Sectionectomy

it helps achieve a relatively long margin at the root of the left hepatic vein

15  Left Lateral Sectionectomy Fig. 15.25  After being repositioned to the original natural position, the lateral segment is grasped with the left hand and pulled caudally. To expose the medial border of the left hepatic vein, the connective tissue is scraped off with Metzenbaum scissors so that the concavity at the bifurcation of the left and middle hepatic veins can be identified

391 Mid. hepatic v.

L hepatic v. L inf. phrenic v.

R hepatic v.

15  Left Lateral Sectionectomy

392

a

b

c Unsafe

Fig. 15.26  A right-angled forceps is carefully passed under the left hepatic vein to scoop the vein, with a fingertip applied to the concave surface of the bifurcation to direct the tip of the forceps to the correct exit (a). Do not push the forceps if any resistance is felt, but instead retract the forceps and dissect the connective tissue

Safe

again—advancing the forceps with the tip facing upward might rupture the bifurcation (b). So, be sure to advance the forceps along the liver parenchyma (c). After encircling the left hepatic vein, a vascular tape is passed around the vein and grasped with mosquito forceps

15  Left Lateral Sectionectomy

393 L sup. hepatic v.

Umbilical fissure v.

Fig. 15.27  The root of the main trunk of the left hepatic vein is quite wide when it receives the left superior hepatic vein, adjunctive veins such as the umbilical fissure vein (left middle hepatic vein) that ascends along the UP while receiving venous return from S3 and S4, and the duct of Arantius, which was previously dissected. An imaginary

Main br. of L hepatic v.

dissection line is set distal to the convergence of the umbilical fissure vein but including the main trunk and the left superior hepatic vein (dotted line). If it is difficult to accurately encircle the veins, do the parenchymal dissection first and then ligate the hepatic veins

15  Left Lateral Sectionectomy

394 L sup. hepatic v.

L hepatic v.

Br. from S3

Dissection plane of liver Umbilical fissure v.

Fig. 15.28  At this point, the lateral segment is discolored dark red, bordered by the falciform ligament. Parenchymal dissection is performed along the imaginary dissection line set 1 cm to the left of the ligament. The procedure is the same as that for right lobectomy. A relatively thick

branch extending from S3 and draining into the umbilical fissure vein may be encountered around the upper border and should be ligated and divided. The dissection area is small, so the dissection can be completed very quickly

15  Left Lateral Sectionectomy

395 Mid. hepatic v.

Umbilical fissure v.

Duct of Arantius (divided)

L sup. hepatic v.

L hepatic v.

Fig. 15.29  The parenchyma around the root of the left hepatic vein is carefully dissected by fragmentation and aspiration with a Cavitron Ultrasonic Surgical Aspirator while also ensuring a sufficient margin for dissection of

the vein. Then, a hemostat is applied to the vein and the specimen is excised. The stump is closed with a 5-0 Prolene suture

15  Left Lateral Sectionectomy

396

Sutured stump of L hepatic v.

Falciform lig.

Cut edge of lesser omentum Ligamentum teres

Fig. 15.30  After achieving hemostasis of the dissection plane, the falciform ligament is placed over the plane as a “lid.” If the ligament is broad enough, the entire plane can

be covered with the ligament. Suturing the ligament to the cut edge of the lesser omentum will result in a beautiful lid that you know will be secure

15  Left Lateral Sectionectomy

397 Sutured stump of L hepatic v.

Dissection plane of liver covered by falciform lig.

Contour of caudate lobe

Fig. 15.31  After washing the abdominal cavity, an 8-mm duple drain is inserted via the right abdominal wall through the foramen of Winslow to the vicinity of the dis-

section plane of the liver. The operation is then completed by closing the abdominal wall, suturing in three layers

Laparoscopic Cholecystectomy

Abstract

Laparoscopic cholecystectomy, which once formed the basis of endoscopic surgery, is a stereotypical procedure consisting of simply dissecting the cystic duct and cystic artery and then detaching the gallbladder from the liver bed. But it has some pitfalls, such as the risk of damaging the common bile duct and mis-

16

identifying the right hepatic artery. So, although it takes only about 40–50  min to complete the procedure, we must perform the procedure with due care. Keywords

Laparoscopic cholecystectomy · Endoscopic surgery · Cystic duct · Cystic artery

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_16

399

16  Laparoscopic Cholecystectomy

400 Fig. 16.1  The surgeon stands on the left side of the patient and makes a 2-cm skin incision below the umbilicus (a). After the second assistant exposes the anterior rectus sheath using two flat retractors, the sheath is grasped on both sides of the midline with Kocher clamps and lifted. A small incision is made on the anterior rectus sheath with a pointed blade and then extended vertically with Mayo scissors. After the flat retractors are repositioned into the rectus sheath to retract the rectus muscle bundle to the left, a small shallow incision is made on the posterior rectus sheath with a pointed blade (b). Finally, Pean forceps are inserted vertically to penetrate the peritoneum into the abdominal cavity. The little finger is inserted into the abdominal cavity to examine the area around the small laparotomy wound for any adhesions. A U-shaped 1 Vicryl suture is placed in the anterior sheath for wound closure and trocar fixation (c). The Kocher clamps are removed, and a 12-mm trocar is inserted as the first trocar (Ⓐ in Fig. 16.2) and fixed with the Vicryl suture. The abdominal cavity is insufflated with carbon dioxide gas through the trocar

a

b

Ant. rectus sheath

c 1 Vicryl suture

16  Laparoscopic Cholecystectomy

401

Fig. 16.2  Additional trocars are inserted in the epigastric region (12 mm, Ⓑ), on the subcostal midclavicular line (5 mm, Ⓒ), and on the preaxillary line (5 mm, Ⓓ). This should be done under guidance with a laparoscope inserted through trocar Ⓐ to avoid damaging the intestine. The surgeon uses trocars Ⓑ and Ⓒ and the first assistant uses trocar Ⓓ 12 mm 5 mm

5 mm 12 mm

16  Laparoscopic Cholecystectomy

402 Fig. 16.3  The patient is positioned head-side up and left side down laterally to secure the operative field. Even with no prior history of inflammation, the gallbladder may have physiological adhesions to the greater omentum. In that case, the adhesions are released with scissors with intermittent electrical activation

Falciform lig.

Ligamentum teres Stomach

Duodenal bulbus

Triangle of Calot

Fig. 16.4  Once ready for the operation, the first assistant grasps the fundus of the gallbladder with forceps inserted from trocar Ⓓ and lifts it cranially (back in the 12 o’clock direction on the screen). The surgeon grasps the pouch of Hartmann with the forceps held by the left hand through trocar Ⓒ and pulls it to the right (in the 9 o’clock direction on the screen) to expand the cystohe-

patic triangle of Calot. If it is difficult to obtain a front view of the triangle of Calot, an oblique-viewing or flexible endoscope might help. If the triangle is hidden behind the colon or duodenum even when the fundus of the gallbladder is lifted, we can get a better view by the first assistant pushing the intestine dorsally with their forceps

16  Laparoscopic Cholecystectomy

403

Sulcus of Rouviere

Fig. 16.5  With an L-hook dissector inserted from trocar Ⓑ, a U-shaped incision is made on the serosa of the triangle of Calot (small arrows). After the serosa is slightly cauterized with the tip of the hook to create an opening, the hook is slid through the opening under the serosa and the serosa is incised by electrically activating the dissector. We need to be sure that we make the U-shaped inci-

sion on the gallbladder side of the sulcus of Rouviere (a groove on the liver parenchyma through which the posterior segmental branch of the Glissonean pedicle enters) because placing the incision away from the gallbladder may result in us misidentifying the right hepatic artery for the cystic artery or damaging the right hepatic duct afterward

404

Fig. 16.6 The incision of the gallbladder serosa is extended by advancing the L-hook dissector along the ventral side of the attachment of the gallbladder to the liver toward the fundus. To avoid penetrating the gallbladder wall, the incision should be advanced by repeatedly sufficiently lifting only the serosa and dividing it by electrically activating the dissector. The grasping forceps Ⓒ

16  Laparoscopic Cholecystectomy

grasping the pouch of Hartmann held by the left hand are pulled caudally (in the 6 o’clock direction on the screen) to apply appropriate tension to the gallbladder serosa to be incised. Do not bring the incision line too close to the liver; keep a distance of about 5 mm from the liver. Stop the incision about 2 cm from the apex

16  Laparoscopic Cholecystectomy Fig. 16.7  The serosal incision is also extended to the dorsal side of the attachment to the liver in the same way. With the grasping forceps Ⓒ held in the left hand, the pouch of Hartmann is twisted toward S4 (small arrow) to apply appropriate tension to the gallbladder serosa that is to be incised

405

406

Fig. 16.8  We move now to detaching the cystic duct. The surgeon grasps the pouch of Hartmann with grasping forceps Ⓒ held by the left hand and pulls it to the right (in the 9 o’clock direction on the screen) to expand the triangle of Calot as much as possible. Next, the fat tissue around the cystic duct is scraped off toward the common bile duct with Maryland’s dissector Ⓑ. The fat tissue on the medial side of the cystic duct contains arteries and veins, so it is

16  Laparoscopic Cholecystectomy

advisable to advance the dissection from the lateral side because if bleeding occurs at this point, the triangle of Calot will be contaminated with blood, interrupting the flow of the operation. Once the lateral or anterior wall of the cystic duct is partially exposed, the dissection is stopped and resumed after confirming that the cystic duct is the correct one based on its positional relationship to the common bile duct and the common hepatic duct

16  Laparoscopic Cholecystectomy Fig. 16.9  The thin fibrous tissue surrounding the cystic duct wall is most likely to be nerves. Forcibly pulling them apart with the Maryland’s dissector may cause bleeding, so they should be scooped with L-hook dissector and divided by electrically activating the dissector. The tissue should then be sufficiently lifted from the cystic duct wall before activating the L-hook dissector, to avoid thermal damage to the duct from the back of the dissector. After these fibrous tissues have been dissected, the cystic duct is further extended and its entire surface is exposed

407

Cystic duct

16  Laparoscopic Cholecystectomy

408 Fig. 16.10  To confirm that the cystic duct has been isolated circumferentially, Maryland’s dissector Ⓑ is advanced to penetrate through the recess formed medial to the duct. During this procedure, the pouch of Hartmann is grasped with grasping forceps Ⓒ held by the left hand and is pulled toward S4 of the liver to help dissector Ⓑ penetrate the connective tissue

&\VWLF GXFW

Fig. 16.11  If the connective tissue cannot be penetrated in one go, dissect the remaining tissue from the posterior side of the triangle of Calot to create an exit for the dissector

Cystic duct

16  Laparoscopic Cholecystectomy Fig. 16.12 After advancing the dissector, its tip is opened along the long axis of the cystic duct to ensure a sufficient margin for transection. If this procedure causes an unexpectedly large amount of bleeding, we might have misidentified the common bile duct for the cystic duct

409

16  Laparoscopic Cholecystectomy

410

a

Sentinel gland

Cystic a.

Cystic duct

b

R hepatic a.

Triangle of Calot

Sentinel gland Cystic a.

Cystic duct

Fig. 16.13  Now the preparation for transecting the cystic duct is almost complete. To further ensure safety, the cystic artery should be identified before proceeding with the operation (a). The cystic artery typically branches from the right hepatic artery, which courses just medial to the neck of the gallbladder. Around the neck of the gallbladder is a lymph node referred to as the sentinel node, which can serve as a landmark for identifying the cystic artery because it usually courses under this lymph node (b) As the residual fat tissue in the triangle of Calot is scraped off along the wall of the gallbladder neck toward

the bile duct, a cord-like structure containing the cystic artery is gradually exposed. However, if the dissection advances too far away from the gallbladder wall, we might have misidentified the right hepatic artery as the cystic artery. This risk is especially high when the branching point of the cystic artery from the right hepatic artery is at a higher level. So, be sure that the dissection proceeds along the neck wall. Once the cystic artery is identified, the dissector is then passed through the recess medial to the artery to reconfirm that the artery enters the gallbladder

16  Laparoscopic Cholecystectomy Fig. 16.14  Once we are confident about having identified the vessels in the triangle of Calot, we can transect the cystic duct. One clip is applied on the cystic side and two clips on the common bile duct side (a), and the cystic duct is then divided with scissors (b)

a

b

411

16  Laparoscopic Cholecystectomy

412 Fig. 16.15  The cystic artery is then clipped and divided with scissors

Cystic duct (ligated)

Cystic a.

Fig. 16.16  Once the artery is cut off, the pouch of Hartmann is liberated from the triangle of Calot. The most critical part of laparoscopic cholecystectomy is now done. The surgeon then pulls the pouch of Hartmann cranially (in the 12 o’clock direction on the screen) with the grasping forceps Ⓒ held in the left hand and gradually detaches the gallbladder from the liver bed with the L-hook dissector Ⓑ. Note that if the dissected cystic artery is thin, the main cystic artery may be hidden deep behind it, so the dissection should proceed carefully with this possibility in mind until the gallbladder neck is completely lifted from the liver bed Cystic duct (confluence)

Cystic a. (root)

16  Laparoscopic Cholecystectomy

413 Ⓒ

Ⓑ Ⓓ

Liver bed

Fig. 16.17  The gallbladder should be detached from the liver bed by entering an appropriate layer so that the muscle layer of the gallbladder is exposed and the intervening connective tissue remains on the liver bed. When scooping the tissues with the L-hook dissector and dividing it using cauterization, the tissue should be sufficiently lifted from the gallbladder wall before electrically activating the

dissector—this avoids thermal damage to the wall from the back of the dissector and subsequent perforation. At the same time, we should be careful not to cut into the liver parenchyma, which may damage branches of the middle hepatic vein, resulting in massive bleeding and possibly requiring the switch to open surgery

414

Fig. 16.18  Although we can continue to complete the detachment from the neck to the fundus, it is also advisable to stop the procedure on the way and resume it from the fundus in the reverse direction to complete the detachment. The first assistant Ⓓ grasps the serosa and lifts up the gallbladder, accompanied by the liver, ventrally (in the

16  Laparoscopic Cholecystectomy

12 o’clock direction on the screen), while the surgeon pulls the fundus dorsally (in the 6 o’clock direction on the screen) with the grasping forceps Ⓒ held in the left hand. This applies countertraction to the serosa of the gallbladder in this area. The serosa is then incised with the back of the electrically activated L-hook dissector

16  Laparoscopic Cholecystectomy Fig. 16.19 With appropriate tension applied continuously to the connective tissue remaining around the fundus, the back of the L-hook dissector is made to gently contact the connective tissue and is then activated to complete the dissection

Fig. 16.20  A specimen retrieval pouch is inserted through trocar Ⓑ to retrieve the gallbladder. The squeezed opening of the bag is grasped with the grasping forceps inserted through trocar Ⓒ. After the endoscope is switched from trocar Ⓐ to trocar Ⓑ, another pair of grasping forceps is inserted through trocar Ⓐ to receive the bag and extricate it from the body through the umbilical wound

415

16  Laparoscopic Cholecystectomy

416 Fig. 16.21 The abdominal cavity is again insufflated to confirm hemostasis of the liver bed. Mild bleeding, such as oozing, can be adequately treated by electrocautery with the L-hook dissector. Any bilious contamination occurring during the operation should be washed out

Fig. 16.22  If necessary, a Penrose drain tube is inserted through trocar Ⓑ and pulled out through trocar Ⓓ. The tip of the tube is placed under the liver near the liver bed and the tube is fixed to the skin

Liver bed

16  Laparoscopic Cholecystectomy Fig. 16.23  The 1 Vicryl suture applied to the anterior rectus sheath around trocar wound Ⓐ is ligated to close the fascia and followed by skin suturing. The operation is completed by closing the remaining wounds with skin sutures

417

Open Cholecystectomy

Abstract

Once you know what is ahead, you will be able to handle surgical instruments such as electrocautery devices and forceps with unwasted motions and cope with most standard surgeries. But you may still find surgery difficult for conditions such as severe cholelithiasis-­ associated cholecystitis (calculous cholecystitis). It is not easy to dig out the soft cystic duct and cystic artery from a rock-­hard, thickened triangle of Calot, even when you know that

17

they are in there. This surgical procedure of open cholecystectomy is one to be reckoned with and requires a certain degree of skill and experience. This chapter describes how to perform this sometimes tricky procedure. Standard operation time is about 60  min but will depend on the severity of inflammation. Keywords

Open cholecystectomy · Triangle of Calot Calculous cholecystitis

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_17

419

420 Fig. 17.1  Patients who require open cholecystectomy tend to have severe chronic cholecystitis, which complicates the dissection procedure. To obtain as good an operative field as possible, a right subcostal skin incision is advisable. The surgeon stands on the left side of the patient

Fig. 17.2  A wound retractor and a rib retractor are applied to secure the operative field

17  Open Cholecystectomy

17  Open Cholecystectomy Fig. 17.3 Preparation for cholecystectomy: The severely inflamed gallbladder tends to be firmly adherent to not only the greater omentum but also the duodenum and transverse colon. These adhesions are released with Cooper scissors (a) and/or electrocautery (b). Because cholecystitis is a benign condition, the dissection should be performed as close as possible to the gallbladder to avoid inadvertently cutting into the intestine adherent to the gallbladder. It is also advisable to detach the greater omentum from the liver to secure an operative field on the right side of the gallbladder (b). This should also be performed slightly away from the liver because dissection too close to the liver can cause detachment of the liver capsule and a considerable amount of bleeding from the parenchyma

421

a

Transverse colon

b

Greater omentum adherent to liver

Duodenal bulbus

17  Open Cholecystectomy

422

Pouch of Hartmann

Fig. 17.4  When ready, the duodenum and the right colic flexure are pushed downward with the left hand to expose the entire underside of the liver. A surgical laparotomy sponge is placed over the left hand and spread over the intestine with long forceps. It is advisable to place the sponge firmly into the right colic flexure (①) and the foramen of Winslow (②) for complete coverage of the intestine Although it is ideal for the first assistant to grasp the gallbladder base and pull it up to expand the triangle of

Calot, this is often difficult to do with a severely inflamed gallbladder. Also, if the gallbladder neck is rock-hard, pulling up the base will not generate enough tension in the triangle of Calot to expand it. This means the pouch of Hartmann should be grasped and pulled with forceps or, if this does not work, the surgeon can expand the triangle with their left hand

17  Open Cholecystectomy

423

Sulcus of Rouviere

Fig. 17.5  The cystic duct is then explored, bearing in mind the course of the duct at the neck of the gallbladder based on preoperative imaging findings. An incision is made on the serosa over the putative anterior aspect of the cystic duct. If a space to accommodate dissection forceps can be created under the serosa, the serosa should be scooped and divided with electrocautery to minimize

bleeding. If the serosa is so hard that a space cannot be created, then the serosa should be incised superficially directly with Metzenbaum scissors. A serosal incision is also made on the posterior side of the cystic duct. During this step, be sure that the incision line is on the gallbladder side of the sulcus of Rouviere

424 Fig. 17.6 Fibrous connective tissue surrounding the cystic duct is scooped with dissection forceps and divided with electrocautery. As was the case with laparoscopic cholecystectomy, it is advisable to proceed with the dissection from the lateral side of the cystic duct. When this step is complete, the cystic duct wall should be partially exposed

Fig. 17.7  We move next to dissection of the anterior and medial sides of the cystic duct, which is inside the triangle of Calot. If there is no inflammation, we should be able to identify a recess easily. This is unlikely though in cases where the triangle is rock-hard. We will need some patience to repeatedly identify fibrous, hard connective tissue that can be cut and then divided with electrocautery. If using dissection forceps does not work, Metzenbaum scissors can be used to cut the tissue little by little and proceed with the dissection

17  Open Cholecystectomy

17  Open Cholecystectomy Fig. 17.8  As we proceed, we might encounter a robust cord-like structure that is slightly thicker than the previously dissected connective tissue. This is likely to be the cystic artery. When we have confirmed that the cord-like structure enters the gallbladder, we should ligate and divide it. Note, however, that even with enhanced vascularization of the gallbladder due to chronic inflammation, it is still possible that this structure is the right hepatic artery, especially when it is very thick. Due to inflammation of the neck of the gallbladder, the right hepatic artery tends to be located closer to the gallbladder than we might expect

425

426

17  Open Cholecystectomy

Cystic a. (cut)

Fig. 17.9 As the dissection of the connective tissue around the cystic duct proceeds, a recess in the triangle of Calot gradually becomes apparent. Dissection forceps are passed through the recess, with the tip of the forceps guided by the left index finger to find the thinnest part. This way the forceps can be passed smoothly. If you are confident that the cord-like structure contains the cystic

duct, you can ligate it on the resection side. But if you are not completely confident, do not go beyond applying a vascular tape to it. Also, if the tissue is still too thick to be penetrated because of incomplete posterior dissection or because the elastic tissue adheres to the tip of the forceps, do not push the forceps and instead interrupt the connective tissue dissection around the gallbladder neck

17  Open Cholecystectomy

427

Vascular tape applied to cystic duct

Fig. 17.10  Detaching the gallbladder from the liver bed: If inflammation has not spread to the body or base of the gallbladder, a circumferential serosal incision should be made before detaching the gallbladder from the liver bed. A small incision is made on the part of the serosa of the gallbladder base about 5 mm away from the liver with Metzenbaum scissors. The surgeon then slides dissection forceps under the serosa, and the first assis-

tant divides the serosa with electrocautery. The incision is connected to the preceding serosal incision at the neck. During the latter half of the incision, the first assistant pulls down the pouch of Hartmann, as shown, to straighten the incision line so that the surgeon can easily insert forceps. Once the serosal incision is completed on one side, the serosa on the contralateral side is incised in the same way

17  Open Cholecystectomy

428 Fig. 17.11 While holding the gallbladder and gallbladder forceps with the left hand, the surgeon detaches the gallbladder from the liver bed with Cooper scissors held in the right hand (a). The dissection advances by entering an appropriate layer so that the muscle layer of the gallbladder is exposed and the connective tissue remains on the liver bed. When encountering a blood vessel that is obviously communicating with the liver bed during the dissection, the surgeon grasps the vessel with forceps and, after having the first assistant cauterize it with electrocautery, divides it with Cooper scissors (b). During the first half of the incision, the first assistant clears the view of the dissected part with the suction tube held in their right hand while grasping the serosal stump on the liver bed with Pean forceps held in their left hand, and during the latter half of the dissection pulls up the liver bed with a flat retractor to apply tension to the dissected part

a

Liver bed

b

17  Open Cholecystectomy

Fig. 17.12  When the entire gallbladder is inflamed and the thickened wall is firmly adherent to the liver bed, it might not be feasible to perform the textbook procedure of detaching the gallbladder from the liver bed (Figs. 17.10 and 17.11). The only feasible option is then to proceed with dissection by directly cauterizing the adhesions with electrocautery while occasionally using the electrocautery tip as a spatula to identify the proper dissection layer. During this procedure, we need to be especially careful not to cut into the liver parenchyma (except when chole-

429

cystectomy including the liver bed is intended for suspected gallbladder cancer). A thick branch of the middle hepatic vein is located directly under the liver bed and damage to this vein by inadvertently cutting into the liver bed will cause unexpected massive bleeding. Hemostasis may well be difficult because of the small skin incision and the liver not being mobilized in many cases of cholecystectomy. If cholecystectomy including the liver bed is a preplanned procedure, then be sure to prepare an adequate operative field before starting the procedure

430

17  Open Cholecystectomy

Fig. 17.13 When prioritizing preservation of the liver bed, we must recognize the risk of cutting into the gallbladder wall and perforating it. If perforation occurs, aspirate the bile, remove the stones, and redirect the dissection to the proper layer. This, at the same time, helps determine the thickness of the gallbladder wall, which makes the subsequent dissection procedure quicker

Hole in gallbladder wall

17  Open Cholecystectomy

431

Gallbladder wall remaining on liver bed Gallbladder neck

Inner side of gallbladder wall

Fig. 17.14  Sometimes the gallbladder wall is so firmly adherent to the liver bed that the two cannot be separated despite trying to redirect the dissection, and this would mean that the liver parenchyma has to be detached together with the gallbladder wall. In such cases, as a compromise, we can leave the adherent portion of the wall on the liver bed and excise only the nonadherent portion. However, when the dissection approaches the neck of the gallbladder, the wall has to be crossed and detached from

the liver bed. This results in a resected specimen of the gallbladder that has a large gaping hole. In such cases, I recommend that you take this opportunity to examine the inner side of the gallbladder neck because it might help identify the entrance to the cystic duct and allow you to confidently identify this duct. The surface of the gallbladder mucosa remaining on the liver bed should then be thoroughly cauterized with electrocautery

432

Fig. 17.15  Finally, while feeling the thickness of the remaining connective tissue (the intervening “mesocyst” between the gallbladder and the extrahepatic Glissonean pedicle) with the ball of the left index finger, the connective tissue is scraped off the gallbladder neck with Cooper scissors. It is advisable to proceed with dissection while holding the scissors nearly perpendicular to the tissue to

17  Open Cholecystectomy

be dissected, which ensures that the dissection layer stays near the gallbladder until the end. Now the end of the operation is in sight, you may feel like cutting through the tissue quickly, but if you have not encountered the cystic artery, consider that it might be contained within this connective tissue and be ready to ligate and divide any suspected cord-like structure you encounter

17  Open Cholecystectomy

433

Fig. 17.16  After dissecting the remaining connective tissue around the cystic duct, the cystic duct is excised by doubleligating with a 3-0 Vicryl suture and dividing it at its proximal end

17  Open Cholecystectomy

434 Liver bed Remaining gallbladder wall (cauterized with electrocautery)

Cystic duct

Fig. 17.17  The abdominal cavity, especially the liver bed, is then examined to confirm hemostasis. Any incomplete hemostasis should be treated by cauterization with electrocautery (spray coagulation). Mikulicz gauze is removed and the small intestine is repositioned so that it does not migrate over the colon into the space under the

liver. If bile leakage occurred during the operation, be sure to wash the abdominal cavity thoroughly. An 8-mm duple drain is inserted via the right abdominal wall into the foramen of Winslow and the operation is completed by closing the abdominal wall, suturing in three layers

Pancreaticoduodenectomy: Whipple Procedure

Abstract

Keywords

This chapter describes subtotal stomach-­ preserving pancreaticoduodenectomy, a major challenge for gastrointestinal surgeons. Akin to the individual medley in a swimming competition, this operation involves advanced resection and reconstruction techniques. This chapter describes in detail a modified Whipple procedure as a reconstruction technique and a pancreatic duct to full-thickness jejunum anastomosis as a pancreaticojejunostomy technique. In the later stage of the operation, gastrojejunostomy and Braun enteroenterostomy are performed using instruments. The standard operation time is 6 h.

Pancreaticoduodenectomy · Whipple ­procedure · Pancreaticojejunostomy

18

Fig. 18.1  The surgeon stands on the right side of the patient and makes an upper abdominal midline incision extending from the xiphoid process to the right of the umbilicus. The peritoneum is incised to the right of the round ligament of the liver to open the abdomen. After placing a wound retractor, exploration of the abdominal cavity is performed and the liver, pouch of Douglas, and other structures are examined

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_18

435

18  Pancreaticoduodenectomy: Whipple Procedure

436

No.12b LN

Inf. vena cava

No.13 LN

Descending part of duodenum

Fig. 18.2  The liver is retracted cranially with an Octopus retractor to secure a view of the operative field, followed by mobilization of the duodenum (Kocher maneuver). The dissection should be done adequately beyond the anterior surface of the inferior vena cava up to the abdominal aorta. For a smooth procedure, the speed at which the surgeon advances the electrocautery device and the force with which the first assistant pulls the duodenum must be well synchronized. As shown in the sagittal cross section in Fig. 18.3b, the correct route for layer separation is to

enter the space between the fusion fascia of Treitz (a fused fascia formed by collision of the duodenal part of the pancreatic head with the retroperitoneum) and the visceral fascia, with the former fascia remaining on the abdominal wall side (thick black arrow 1  in Fig.  18.3b). If tumor invasion to the connective tissue on the posterior side of the pancreas is suspected, the dissection should be done in an appropriate layer so that the fusion fascia remains attached to the resection side (route indicated by a thin arrow 1′ in Fig. 18.3b)

18  Pancreaticoduodenectomy: Whipple Procedure

437

a

Acc. R colic v.

b

Duodenal bulbus Greater omentum

1’

1

nc.

Pa

Fascia of Gerota

Fusion fascia of Treitz

2 2 1 3

Fusion fascia between greater omentum and transverse mesocolon Fusion fascia between horizontal part of duodenum and transverse mesocolon

Fig. 18.3  The greater omentum is now detached from the transverse mesocolon (white arrow 2 in b), and divided at its attachment to the omental tenia. This procedure advances in the opposite direction to the procedure in total gastrectomy (Fig. 4.11) but in the same dissection layer (see also Fig. 4.13a). When the right border of the omental

bursa is reached from the back (right) side, it is incised and the incision is extended toward the anterior surface of the pancreatic body. The transverse mesocolon is also detached from the uncinate process of the pancreas and the anterior aspect of the horizontal part of the duodenum (white arrow 3 in b)

18  Pancreaticoduodenectomy: Whipple Procedure

438

a SMV Gastrocolic trunk of Henle

Mid. colic v.

R colic a. & v.

Web-like fused fascia remaining between duodenum and transverse mesocolon

Acc. R colic v.

b

Web-like fused fascia

Fig. 18.4  If we have carried out the dissection in the correct layer, we can now see a web-like fused fascia remaining between the duodenum and the transverse mesocolon (a). This fascia is divided with electrocautery (b). This corresponds to what we see in right hemicolectomy where a remnant of the fusion fascia of Toldt can be seen after the ascending colon has been mobilized from two directions (see Fig. 6.13a and b). On the way, the accessory right colic vein is encountered as a stretched cord-like structure and should be ligated and divided. Once the dissection has reached the superior mesenteric vein (SMV), the duodenal part of the pancreatic head is fully mobilized. Then, while pulling the horizontal part of the duodenum, the connective tissue around the duodenum is scraped off with Cooper

scissors toward the ligament of Treitz to lengthen the duodenal neck. Even if we detach the duodenum so strongly as to open the ligament of Treitz from this side, we still have a long way to go and can see that the ligament of Treitz is a long structure. This procedure mainly dissects the dorsal side of the horizontal part of the duodenum and eventually reaches the back side of the ligament of Treitz, forming a hole on the retroperitoneum of a recessed part (the paraduodenal recess; see Fig. 18.25) between the proximal jejunum and the inferior mesenteric vein (IMV). Also, at this point, the right colic vessels are already exposed on the dissected surface of the transverse mesocolon because these vessels are located cranial to the horizontal part of the duodenum, as described in Chap. 6 on right hemicolectomy

18  Pancreaticoduodenectomy: Whipple Procedure

439 Direct br. L gastric v.

PSPDV PV

R gastroepiploic v.

Splenic v.

Infrapyloricv.

IMV

ASPDV

Gastrocolic trunk of Henle

Mid. colic v.

Acc. R colic v.

PIPDV AIPDV

SMV J1v

Fig. 18.5  Anatomy of the venous system around the pancreatic head: There are innumerable possible variations, so the most characteristic pattern is shown here. The anterior superior pancreaticoduodenal vein (ASPDV; ①), which we talked about a lot in Chaps. 3 and 4 on gastrectomy, converges with the right gastroepiploic vein and the accessory right colic vein to form the gastrocolic trunk of Henle and drains into the SMV. The anterior inferior pancreaticoduodenal vein (AIPDV; ②) drains into the SMV at a level slightly lower than the gastrocolic trunk of Henle,

usually after forming a common trunk with the posterior inferior pancreaticoduodenal vein (PIPDV; ③) and the first jejunal vein (J1v). Another vein, the posterior superior pancreaticoduodenal vein (PSPDV; ④), drains into the portal vein at the level of the upper border of the pancreas. Several more short veins also drain from the pancreatic head directly into the portal vein or the SMV. These veins must be identified and dissected accurately to prevent bleeding during pancreaticoduodenectomy

18  Pancreaticoduodenectomy: Whipple Procedure

440

a

R gastroepiploic v.

6

ASPDV

SMV

Acc. R colic v. (ligated)

b R gastropiploic v.

No.12b LN 6

17 6

ASPDV

6

17

17

17

Fusion fascia between greater omentum and transverse mesocolon (cut, *) R gastroepiploic v. + ASPDV

17 *

No.13 LN

Gastrocolic trunk of Henle (ligated)

Fig. 18.6  The gastrocolic trunk of Henle is ligated and divided (a). The superior mesenteric lymph nodes, which are referred to as the No. 14v nodes during gastric cancer surgery, are included in the No. 17b inferior prepancreatic head lymph nodes of Group 1 according to the Japanese classification of pancreatic carcinoma. The sagittal cross

Acc. R colic v.

section at the level of the portal vein and the SMV (b) shows the gradual revealing of the contour of the duodenal part of the pancreatic head (which is to be resected) by procedures such as Kocher maneuver, detachment of the greater omentum from the transverse mesocolon, and division of the gastrocolic trunk of Henle

18  Pancreaticoduodenectomy: Whipple Procedure

441

a

SMV

6

Tumor

Gastrocolic trunk of Henle (ligated)

b PLph-I

Descending part of duodenum

Spleen

Ca

nc

er

SMV SMA

PLph-II IVC

Ao

R celiac ganglion

Fig. 18.7  Now, to determine whether the carcinoma is resectable, the gap between the pancreas and the SMV is entered with two dissectors (a). This is just like opening the front door to someone’s house to see if they will let you in. If both structures can be completely separated to allow the dissectors to reach the upper border of the pan-

L celiac ganglion

creas, then the tumor is resectable and subsequent procedures can commence. In actual cases, portal invasion of cancer of the head of the pancreas commonly occurs on the right posterior side (b) and cannot always be identified in the current procedure, although we can still determine whether portal reconstruction is possible

18  Pancreaticoduodenectomy: Whipple Procedure

442

No.12p LN Cystic a. Lesser omentum 5

12b

R gastric a. & v.

12a 6 17 17

Fig. 18.8  Lymph node dissection is performed between the hepatoduodenal ligament and the upper border of the pancreas. An incision is made on the lesser omentum and extended transversely on the peritoneum of the anterior surface of the hepatoduodenal ligament toward the triangle of Calot. After the cystic artery is ligated and divided in the triangle, the gallbladder is detached from the liver bed (white arrows). The cystic duct should not be divided

and should be excised with the specimen. Then, the proper hepatic artery is identified and the connective tissue around the artery, which contains the No. 12a lymph nodes and nerve fibers, is removed with electrocautery by gathering them toward the duodenum. On the way, the right gastric artery and vein are ligated and divided at their root once exposed

18  Pancreaticoduodenectomy: Whipple Procedure

443

a

Post. wall of omental bursa

L gastric v.

R gastric a. (root)

Gastroduodenal a. R celiac ganglion Common hepatic a.

PSPDA

No.8a/ p LN (dissected)

b

Proper hepatic a.

12b

Common hepatic a.

No.5,12a LN R gastric a. (ligated)

Fig. 18.9  With the stomach pulled caudally to obtain a clear view of the upper border of the pancreas, an incision is made on the retroperitoneum of the posterior wall of the omental bursa (a). The connective tissue around the common hepatic artery, which contains the No. 8a and 8p lymph nodes and nerve fibers, is dissected with electrocautery, orientated from the root of the left gastric artery toward the gastroduodenal artery, which is the opposite direction to that for gastric cancer surgery. Because there may be tumor invasion to the nerve, we should dissect over the arterial surface while staying in a layer that allows us to remove a net-like nerve bundle surrounding

the arterial surface (slightly deeper than the dissection layer for gastric cancer operation). Because these lymph nodes are connected to the No. 12p nodes, they should not be separated and will be dissected en bloc later (see Figs.  18.10 and 18.11). After completing the dissection around the proper hepatic artery and the common hepatic artery and exposing the root of the gastroduodenal artery, the artery is ligated and divided (b). If anastomotic leak of the pancreaticojejunostomy occurs, rupture or aneurysm formation at the stump of the gastroduodenal artery can be fatal, so the ligation should be made carefully to avoid damaging the intima of the artery

18  Pancreaticoduodenectomy: Whipple Procedure

444

Ant. surface of portal v.

No.12p LN

Proper hepatic a.

Common hepatic a.

Gastroduodenal a. (root)

Fig. 18.10 Periportal lymphadenectomy is performed next. The surgeon retracts the proper hepatic artery with the left thumb to expose the anterior surface of the portal vein, inserts the remaining four fingers into the foramen of Winslow to push the No. 12p lymph nodes located behind the hepatoduodenal ligament out to the left of the portal vein, and asks the first assistant to grasp the nodes with for-

ceps. Maintaining this position, the surgeon detaches the lymph nodes from the portal vein wall with Metzenbaum scissors. The dissection should proceed in an appropriate layer so that the portal vein wall is exposed with no residual membrane over the surface of the portal vein. This helps to accurately identify and cauterize all small branches draining from the lymph nodes into the portal vein

18  Pancreaticoduodenectomy: Whipple Procedure

445

b 12 Gastroduodenal a. (root)

No.12p LN

No.5,12a LN

No.8a/p LN

Fig. 18.11  After isolating the No. 12p portal lymph nodes isolated, they are coupled with the previously detached No. 8a and 8p nodes, brought behind the com-

mon bile duct, and attached to the No. 12b bile duct lymph nodes. Before doing this, the proper hepatic artery should be taped and retracted to the left

18  Pancreaticoduodenectomy: Whipple Procedure

446

a

Common hepatic a. Gastroduodenal a. (root) Portal v.

b

Gastroduodenal a. (ligated)

PSPDV R gastric a. (ligated)

Fig. 18.12  We now move on to lymphadenectomy along the right border of the portal vein. Using two dissectors, the right wall of the portal vein is pushed with the dissector held by the right hand, while the surrounding connective tissue is detached with the dissector held by the left hand (a). As the dissection proceeds downward, the posterior superior pancreaticoduodenal vein (PSPDV) can be identified as it drains from the upper border of the pancreas into the right wall of the portal vein. This vein is ligated and divided (b). To identify these small veins easily, we should advance the dissection in an appropriate

layer so that the portal vein wall is exposed with no residual membrane over it The dissection of the hepatoduodenal ligament should be performed based on the concept that except for the connective tissue around the hepatic artery and the portal vein, which are to be preserved, all other connective tissues should remain attached to the bile duct or the duodenum, which are to be excised

18  Pancreaticoduodenectomy: Whipple Procedure

447 Tip of dissector passed through layer

12b

PSPDV (ligated)

8p

8a

12 p

12a 6

Gastrocolic trunk of Henle (ligated)

Fig. 18.13  A dissector is again inserted into the layer that was previously entered to detach the SMV from the pancreatic parenchyma (Fig.  18.7), and it is advanced until its tip is beyond the upper border of the pancreas

Up to this point, pancreaticoduodenectomy can be completed. After this point, the operation enters the stage of no-return

448

18  Pancreaticoduodenectomy: Whipple Procedure

Fig. 18.14  Transection of the stomach: The greater omentum is incised toward an imaginary transection line of the stomach set in the antrum 3–4 cm proximally from the pyloric ring. An arcade formed by the right gastroepiploic artery and vein is ligated and divided when reached

Fig. 18.15 The corresponding arcade on the lesser curvature side is also ligated and divided

R gastroepiploic a. (ligated)

18  Pancreaticoduodenectomy: Whipple Procedure

449

56

cm

Fig. 18.16 The stomach is transected with a linear stapler. Because the stomach wall is relatively thick around the antrum, a green cartridge (3.5 mm) should be used. The 5–6 cm range from the transection line toward the greater curvature should be cleared of any gastric wall branches because this area will be anastomosed to the jejunum during reconstruction

450

18  Pancreaticoduodenectomy: Whipple Procedure

Stump of stomach

Fig. 18.17  Transection of the bile duct: The common hepatic duct is clamped with a bulldog clamp and divided. The stump on the resection side is ligated with a 1-0 silk suture. The bulldog clamp may be kept in place until reconstruction if percutaneous transhepatic cholangiod-

rainage (PTCD) has been placed. Otherwise, the clamp should be removed occasionally, and accumulated bile should be suctioned to prevent an excessive increase in biliary pressure

18  Pancreaticoduodenectomy: Whipple Procedure

a

451

Common hepatic duct

Hepatic duct (ligated)

la atu sp

Vascular tape

c

b

SMV Bad transection

Fig. 18.18  Transection of the pancreas: After an imaginary transection line is set on the pancreas along and above the SMV (the thinned area), a vascular tape is applied to the portion about 2 cm caudal to the line and lightly tightened with a short-cut Nelaton catheter. A stump clamp is applied on the resection side of the line. With a small spatula (brain spatula) placed between the pancreas and

SMV Good transection

the SMV as an underlay, the pancreas is transected with a pointed blade, ensuring that the dissection plane is perpendicular to the surface (a). Because the surgeon is on the right side of the patient, the dissection plane tends to be like that shown in (b). Instead, the plane in (c), which has a longer dorsal line of the pancreas, should be created for ease of later pancreaticojejunostomy

452

18  Pancreaticoduodenectomy: Whipple Procedure Dorsal panc. a.

Fig. 18.19  After transecting the pancreas, the cut surface is examined to identify the main pancreatic duct. If the duct is distended as shown, then no additional procedure is needed. If it is narrow, we need to insert a pancreatic duct tube and confirm that the tube can be advanced without resistance. The tube can be kept in place until reconstruction to drain pancreatic juice out of the wound, as long as it does not interfere with the subsequent procedures Vigorous bleeding might occur from a small artery on the cut surface and hemostasis can be achieved by placing

a U-shaped 4-0 PDS suture at the bleeding point. In parallel with bleeding control, the vascular tape used to tighten the neck of the pancreatic stump is gradually loosened and removed. If the bleeding is difficult to control due to vigorous blood flow, one of the supplying arteries (the dorsal pancreatic artery) can be dissected

18  Pancreaticoduodenectomy: Whipple Procedure

453

Fig. 18.20  For ease of later anastomosis, the connective tissue on the posterior side of the pancreas near the stump is dissected to obtain a “long neck”

454

18  Pancreaticoduodenectomy: Whipple Procedure

Direct br. draining from pancreatic head into SMV

Second assistant’s left hand

Fig. 18.21  The right wall of the SMV is trimmed. Short veins draining directly from the pancreatic head into the SMV are identified, scooped with right-angle dissection forceps, and ligated and divided. There are three to four such veins. During this procedure, the second assistant pulls the pancreatic head to the right with the stump clamp held in the left hand, while the first assistant pulls the SMV to the left with two dissectors to secure the operative field. Once one branch is dissected, the dissector is repositioned deeper to dissect the next branch that drains into a deeper portion (into the posterior wall of the SMV). This procedure is repeated over the right three-quarters of the

circumference of the SMV to which the pancreas is attached. For accurate identification of the small branches, the dissection should also proceed in an appropriate layer so that the wall of the SMV is exposed with no residual membrane over it. After all of the small branches have been dissected, the pancreatic stump on the resection side is ligated with a 1-0 silk suture and the stump clamp is removed. Because this area is most commonly affected by portal invasion of pancreatic head cancer, we may need to consider combined resection of the portal vein when the dissection cannot be performed safely

18  Pancreaticoduodenectomy: Whipple Procedure

455

SMA

I

SMV II Gastrocolic trunk of Henle (ligated)

PIPDV

AIPDV J1v (common trunk with A/PIPDV)

Fig. 18.22  Dissection of the inferior pancreaticoduodenal vein: When the dissection along the right wall of the SMV reaches the uncinate process, the first assistant exchanges the dissectors for two curved retractors and pulls the SMV to the left over the superior mesenteric artery (SMA). As the dissection continues, the root of the first jejunal vein (J1v) is encountered near the upper border of the ascending part of the duodenum. This is because when the SMV is twisted, the J1v, which enters the SMV from its left posterior aspect in the natural position, passes behind the SMV as if winding around it and enters it from the right posterior aspect. Inserting forceps without knowing this may cause massive bleeding. Also, the anterior/ posterior inferior pancreaticoduodenal veins (A/PIPDV) often form a common trunk with the J1v, in which case

these veins drain into the J1v near its root. By ligating and dividing the IPDV at this portion, the communication between the pancreatic head and the portal system is completely shut down. Variations are common though, so the dissection should advance based on a full understanding of the course and branching pattern of the J1v The remaining task is to dissect arteries. The arterial branches to be dissected are embedded in a nerve bundle referred to as the pancreatic head nerve plexus (PLph). As shown in Fig. 18.7b, the nerve bundle extending from the right celiac ganglion into the upper medial border of the uncinate process is identified as the PLph-I (I) and the broad bundle extending from the superior mesenteric plexus into the uncinate process along the entire length of its medial border is identified as the PLph-II (II)

18  Pancreaticoduodenectomy: Whipple Procedure

456

Root of J1a (common trunk with IPDA)

Root of J1v Duodenojejunal junction IPDV

PIPDA

AIPDA

J1a / v Anastomosing a.

Mid. colic v.

Fig. 18.23  Anatomy of the inferior pancreaticoduodenal artery (IPDA): The IPDA branches from the SMA near the upper border of the duodenum and often forms a common trunk with the first jejunal artery (J1a) in almost one in two cases. The root of the IPDA is usually undivided, as shown, but it may be split into the anterior and posterior branches. Also, regardless of whether or not the IPDA and the J1a form a common trunk, an anastomosing artery connecting the two arteries is seen in about 60% of cases The J1a crosses the front of the duodenum and comes out of the ligament of Treitz along with the J1v. Because

the artery does not give off any branches until reaching the lower border of the proximal jejunum, the anterior and posterior walls of the duodenum can be easily detached from the ligament of Treitz We should keep in mind the discontinuity of the direction of blood vessel attachment between the proximal jejunum (which has a distinct mesentery and is supplied by blood vessels entering from the lower medial direction) and the ascending part of the duodenum (which is supplied by a short vascular pedicle extending from the anastomosing artery)

18  Pancreaticoduodenectomy: Whipple Procedure

a

457 L gastric a.

R celiac ganglion

Common hepatic a. Celiac piexus PLph-I

Fig. 18.24  The PLph is then dissected. The first assistant retracts the SMV to the left with two curved retractors. The surgeon pulls the pancreatic head laterally to the right with the left hand to apply tension to the nerve bundle of the PLph-I.  The nerve bundle is the scooped with dissection forceps and divided in stages with electrocautery (a). Then, with the pulsating SMA held between the thumb and middle finger of the left hand, the PLph-II is dissected along the right border of the SMA (b). This nerve bundle should be ligated and divided because it may contain a branch directly draining from the SMA into the uncinate process. In this operative field,

the dissection should be stopped before reaching the root of the IPDA because the root can be exposed more clearly and trimmed more cleanly by drawing out the duodenum after jejunal transection and pulling the entire specimen to the right Given that the cancer of the pancreatic head may have spread into the PLph, we should, at the very least, resect the plexus located to the right of the SMA.  However, because complete circumferential resection of this plexus always results in refractory diarrhea, determine the range of dissection by considering the balance between risk and possibility of cure

18  Pancreaticoduodenectomy: Whipple Procedure

458

Direct br. draining from SMA into uncinate process

b PLph-I (dissected)

SMA Root of J1a Root of J1v PLph-II

IPDA

Fig. 18.24 (continued)

18  Pancreaticoduodenectomy: Whipple Procedure

459

a

SMV

Vasa recta

First marginal a/v branching from J1a/v

J1a/v

b SMV

IMV

Paraduodenal recess

J1a/v

Fig. 18.25  Transection of the jejunum: With the transverse colon everted cranially, the peritoneum is divided along the right border of the proximal jejunum. If circumstances permit with respect to lymph node dissection, the J1a/v should be preserved and, after ligating and dividing two to three straight vessels, an appropriate route should be determined to divide the first marginal artery/vein branching from the J1a/v (a) The jejunum is then everted to the right and an incision is made on the peritoneum of a recess between the

left border of the proximal jejunum and the inferior mesenteric vein (IMV) (the paraduodenal recess) and connected to the incision made on the right side (b). The peritoneum on this side is the posterior side of the ligament of Treitz and should already be perforated if the Kocher maneuver was performed completely earlier (Fig. 18.4). After trimming the intestinal wall, the jejunum is transected with a linear stapler at the position indicated by the arrow

18  Pancreaticoduodenectomy: Whipple Procedure

460

SMA

IPDA SMV

Ligament of Treitz

Fig. 18.26  After it is confirmed that the anterior, posterior, and lower walls of the duodenojejunal junction are completely detached from the inner surface of the

ligament of Treitz, the resection-side stump of the jejunum is pulled and allowed to pass behind the SMA/V to the right of it

18  Pancreaticoduodenectomy: Whipple Procedure

461

a

Common trunk J1a

Anastomosing a.

Fig. 18.27  The resection specimen is now anchored only by the IPDA. The entire specimen is grasped by hand and pulled to the right to apply tension to the cord-like structure composed of the IPDA and the nerve bundle. The arterial wall is exposed by carefully removing the nerve

fibers surrounding the artery. The anastomosing artery between the IPDA and J1a is ligated and divided close to J1a (a), followed by ligation and division of the IPDA at the level of the common trunk with the J1a (b). This allows the specimen to be excised

18  Pancreaticoduodenectomy: Whipple Procedure

462

b AIPDA

PIPDA

Common trunk J1a

Root of J1a

Anastomosing a. (ligated)

Fig. 18.27 (continued)

18  Pancreaticoduodenectomy: Whipple Procedure

463

a

Hole Hole IMV Mid. colic v.

b Planned site of hepaticojejunostomy

SMV Hole formed on paraduodenal recess (not to be used)

Planned site of gastrojejunostomy

Planned site of Braun enteroenterostomy

Planned site of pancreaticojejunostomy

Fig. 18.28  For reconstruction, we use the Whipple procedure here as the standard reconstruction procedure. Two holes are made on the transverse mesocolon on both sides of the middle colic vessels (a), and the jejunum is lifted as

shown (b). Because the jejunal stump is to be fixed to the abdominal wall, allow for a margin of 10–15 cm between the stump and the planned most proximal anastomotic site to the hepatic duct

18  Pancreaticoduodenectomy: Whipple Procedure

464

Pancreatic duct tube

Fig. 18.29  Pancreaticojejunostomy: This should be done basically by performing pancreatic duct to full-thickness jejunum anastomosis. A small incision is placed at the planned anastomotic site of the jejunal wall with electrocautery. Through this opening, the guiding part of a pan-

creatic duct tube is inserted and advanced toward the jejunal stump and pulled out of the lumen approximately 3  cm before the stump (the margin for Witzel jejunostomy). The other end of the tube is tentatively inserted into the main pancreatic duct by about 5 cm

18  Pancreaticoduodenectomy: Whipple Procedure

465

1

3 1 2 2

4 5

4-0 Vicryl suture

Fig. 18.30  Step 1: Suturing of the pancreatic parenchyma. A 4-0 Vicryl suture with straight needles at both ends is passed through the pancreatic parenchyma and the intestinal seromuscular layer in both directions. Although the number of sutures varies depending on the cross-­ sectional area of the pancreas, for a pancreas of the standard size, two sutures ( 1 and 3 ) should be passed on the cranial and three sutures ( 2 , 4 , and 5 ) should be passed on the caudal sides of the main pancreatic duct. The two closest sutures on both sides of the main pancre-

atic duct should pass as close as possible to, but not through, the duct. The needles should be advanced parallel to the cut surface at a depth of about 5  mm. On the jejunal side, the needles should be inserted according to the shape of the cut surface of the pancreas. After completing this step, a cloth with round holes is placed over the suture threads to prevent them from getting entangled with the suture threads used for subsequent pancreatic duct suturing

18  Pancreaticoduodenectomy: Whipple Procedure

466

a

䐟

3 1

4 5

䐠 5-0 PDS 2

䐟

䐠

4 䠑

b

d

c

Good suturing

Bad suturing

Needle inserted deep in both pancreatic duct and parenchyma

Needle inserted in pancreatic duct but not in pancreatic parenchyma

Fig. 18.31  Step 2: Suturing of the pancreatic duct. A 5-0 PDS suture with needles at both ends should be used. After the pancreatic duct tube has been removed temporarily, the first suture is passed through the midpoint of the anterior wall of the duct (①) and grasped with mosquito forceps without removing the needle (a). With the canopy removed, we have a better operative view. Then, the second suture is passed on the cranial side of the duct (②) in

both directions (i.e., from inside to outside of the pancreatic duct (a) and then from inside to outside of the jejunum) and is grasped with mosquito forceps (b). When suturing the pancreatic duct, the needle should be inserted deep in the duct to ensure that the suture passes through both the duct and pancreatic parenchyma (c). If the needle is inserted shallowly, the suture cannot pass through the pancreatic parenchyma (d)

18  Pancreaticoduodenectomy: Whipple Procedure

467 2

1 5 2 4

1

6

3

3 6

3 1

Fig. 18.32  The remaining sutures are placed sequentially in the following order: caudal side (③) and midpoint of the posterior wall (④), ⑤, and ⑥. After all sutures have

been passed, sutures ⑤, ④, and ⑥ are ligated in this order. Sutures ② and ③ are not ligated yet

18  Pancreaticoduodenectomy: Whipple Procedure

468 Fig. 18.33 The pancreatic duct tube is inserted and fixed. The depth of insertion into the main pancreatic duct (4–5 cm) should be determined beforehand and that portion of the tube is ligated with a 4-0 Vicryl suture. After the needle has been passed through the jejunal mucosa, the tube is inserted in the main pancreatic duct and the slack of the suture is taken up to make a ligation. This allows for adjusting stent length while ensuring fixation

1

2

4-0 Vicryl suture 3

4-5 cm

1 2 7

1

2 2 4 3

8

5

3

3

1 2 4 5

Fig. 18.34 Suture ① is passed through the jejunum and then additional sutures ⑦ and ⑧ are placed, for a total of eight sutures (for a dilated pancreatic duct, more sutures may be added as needed). The sutures on the pancreatic side should be deep enough that the tip of the needle

scratches the tube. Sutures ②, ⑦, ①, ⑧, and ③ are ligated in this order and cut. Make sure that these ligations will not loosen, but at the same time avoid tying them too tight that the pancreatic parenchyma is cut

18  Pancreaticoduodenectomy: Whipple Procedure

469

Slack of pancreatic duct tube Purse-string suture

3

1

2

4

5

Fig. 18.35  A purse-string 4-0 Vicryl suture is placed at the exit of the pancreatic duct tube from the lifted jejunum, with allowance for the tube to be moderately slack inside the jejunum

Fig. 18.36 Tube jejunostomy is completed using Witzel’s method. The last suture is also passed through the tube to fix it

18  Pancreaticoduodenectomy: Whipple Procedure

470 1

1

3

4

5

2

5

4

Fig. 18.37  The 4-0 Vicryl sutures passed through the pancreatic parenchyma and the jejunal seromuscular layer are tied. Before tying the sutures, confirm that there is not any slack by pulling both ends of the suture and feeling the amount of force transmitted. Ligations should be made

so that the cut surface of the pancreas and the jejunal wall are in tight contact with each other (i.e., the jejunal wall is pressed against the pancreas). This completes pancreaticojejunostomy

18  Pancreaticoduodenectomy: Whipple Procedure

471

Pancreatic duct tube

Bile duct tube

Fig. 18.38  Hepaticojejunostomy: A small incision, consistent with the diameter of the hepatic duct, is made at the planned anastomotic site of the jejunal wall with a pointed blade. Through the opening, the guiding part of a bile duct tube is inserted, advanced toward the jejunal stump, pulled

out of the lumen at a point slightly away from the outlet for the pancreatic duct tube, and grasped together with the anastomotic orifice using Satinsky forceps. No bile duct tube is required when a PTCD has been placed or the hepatic duct has a large diameter

18  Pancreaticoduodenectomy: Whipple Procedure

472 3

1

2

Fig. 18.39  The 4-0 PDS suture with a needle at one end is used. Two sutures are passed through the hepatic duct, from the outside to the inside, and then the jejunum, from inside to outside, at their left and right ends (① and ②) and are grasped with mosquito forceps. Another suture (③) is passed through the midpoint of the posterior wall of the

hepatic duct, from inside to outside, and then the jejunum, from outside to inside. Depending on the diameter of the hepatic duct, more sutures may be added in between as needed. The mosquito forceps are sequentially passed through Kelly forceps to avoid entanglement of the sutures

18  Pancreaticoduodenectomy: Whipple Procedure

473

1 2

1

2

4

5

7 3

6

7

Fig. 18.40 Suture ④, ⑤, ⑥, and ⑦ are passed through the posterior wall of the hepatic duct and tied; the sutures at both ends remain untied. The second assistant should assist by approximating the jejunal limb to the hepatic duct stump

18  Pancreaticoduodenectomy: Whipple Procedure

474

2

1

9

1

10

8

11

12

2

Fig. 18.41  After the bile duct tube is inserted and fixed in the same fashion as for pancreaticojejunostomy, the anterior wall is sutured (⑨-12)

18  Pancreaticoduodenectomy: Whipple Procedure

Pancreatic duct tube

Bile duct tube

Fig. 18.42  Tube jejunostomy is completed using Witzel’s method. This completes hepaticojejunostomy

475

18  Pancreaticoduodenectomy: Whipple Procedure

476

Anastomotic site of hepatic duct and pancreas

Anal side of jejunum

Fig. 18.43  Gastrojejunostomy: A small opening is made on the greater curvature of the remnant stomach 6  cm proximal to the transection line with electrocautery. After the jejunal loop is lifted through another opening made on the transverse mesocolon, the site of anastomosis to the stomach is determined while ensuring a margin for Braun

enteroenterostomy. A small opening is also made on the jejunal loop with electrocautery and an antiperistaltic side-to-side anastomosis is made with a linear stapler (60 mm, blue). The opening for stapler insertion is closed with a 4-0 PDS suture

18  Pancreaticoduodenectomy: Whipple Procedure

Hepaticojejunostomy

477

Pancreaticojejunostomy

Gastrojejunostomy

Braun enteroenterostomy

Fig. 18.44  Braun enteroenterostomy: A Braun enteroenterostomy is made with a linear stapler (40 mm, white). The remnant stomach is fixed to the transverse mesocolon

478

18  Pancreaticoduodenectomy: Whipple Procedure

Bile duct tube

Pancreatic duct tube

Fig. 18.45  The pancreatic and bile duct tubes are pulled out of the abdominal wall and the parts of the jejunal wall around the tube outlets are fixed to the parietal peritoneum. Although by this time you may be very tired and

finding it difficult to concentrate fully, make fine sutures by advancing the needle from back to front while considering the suturing route. The tubes pulled out of the body are further fixed to the skin of the abdominal wall

18  Pancreaticoduodenectomy: Whipple Procedure

479

Hepaticojejunostomy

Penrose drain tubes (pancreaticojejunostomy site)

Bile duct tube Pancreatic duct tube Gastrojejunostomy Dupe drain tube (hepaticojejunostomy site)

Pancreaticojejunostomy

Braun enteroenterostomy

Fig. 18.46  After washing the abdominal cavity, an 8-mm duple drain tube is inserted from the right abdominal wall and placed under the liver (behind the hepaticojejunostomy site) and two Penrose drain tubes are inserted from

the left abdominal wall and placed behind and in front of the pancreaticojejunostomy site, respectively. The operation is completed by closing the abdominal wall, suturing in three layers. Congratulations, you’re done!

Anatomy of the Inguinal Canal and Surrounding Structures

Abstract

The inguinal canal is a conduit through which the spermatic cord in men or the round ligament of the uterus in women passes through the abdominal wall. The wall of the inguinal canal is composed of various anatomical components, making it surprisingly difficult to fully understand its threedimensional structure. This chapter intends

19

to complete the surgical anatomy of the inguinal canal on paper by sequentially attaching the parts that constitute the canal, from inside to outside, viewed from within the abdominal cavity. Keywords

Inguinal canal · Spermatic cord · Round ligament of the uterus

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_19

481

19  Anatomy of the Inguinal Canal and Surrounding Structures

482

Aponeurosis of ext. oblique m. Rectus abdominis m. Ant. wall of rectus sheath Ext. oblique m.

Intercrural fibers

Linea alba

s

s

cru

ru

al

e

lc

ter

M

a di

La

Inf. epigastric a. & v.(divided,*)

Superficial inguinal ring

Deep inguinal ring Fascia transversalis Inguinal lig,

Inf. epigastric a. & v. (*)

Ligament of Cooper

Preperitoneal space Peritoneum

Lacunar lig.

r de ad Bl Lateral umbilical lig. Median umbilical lig.

Fig. 19.1  The right inguinal region viewed from the abdominal cavity. As the part closest to the body surface, the external oblique muscle and the rectus abdominis muscle are shown. Under the external oblique muscle are the fascia transversalis, preperitoneal space, and peritoneum, which are illustrated like the unopened pages of a book. The inferior epigastric vessels, which are connected to the external iliac vessels and supply the rectus abdominis muscle, are divided (asterisk). The external oblique muscle continues as an aponeurosis (the external oblique aponeurosis), as shown, and its inner layer forms the anterior wall of the rectus sheath and then fuses with the posterior sheath at the midline to form the linea alba. At the lower border, thickened aponeurotic fibers form the inguinal ligament, with a triangular defect formed above. The two sides of the triangle are referred to as the medial crus and lateral crus, respectively. The body surface side of the defect is covered by the intercrural fibers continuing from the vastus femoris muscle and forming the anterior wall of the inguinal canal; the innermost side of the defect lacks these fibers and instead forms an outlet for the spermatic

cord, the superficial inguinal ring. Although called a “ring,” the superficial inguinal ring has no clear borders because the aponeurotic fibers are partially diffused over the spermatic cord passing through it. A thin membrane is seen continuous from the aponeurotic fibers and covering the surface of the spermatic cord and is referred to as the external spermatic fascia The inguinal ligament, which is attached to the anterior superior iliac spine and the pubic tubercle, supports the spermatic cord from below and forms the lower wall (floor) of the inguinal canal. Before reaching the pubic tubercle, the inguinal ligament fuses with the periosteum covering the upper border of the superior pubic ramus (the ligament of Cooper) to form the lacunar ligament. The gap between the inguinal ligament and the superior pubic ramus is divided into the vascular lacuna (①) and the muscular lacuna (②). The lacunar ligament forms the medial border of the vascular lacuna. The vascular lacuna allows for passage of the femoral artery and vein; the muscular lacuna allows for passage of the iliopsoas muscle and the femoral nerve

19  Anatomy of the Inguinal Canal and Surrounding Structures

483

Bow-shaped free lower border

Int. oblique m. Post. wall of rectus sheath Cremaster m.

Arcuate line

Iliac crest

Gonadal a. & v.

Testis

.

Vas deferens

Fig. 19.2  The internal oblique muscle part is attached to the underside of the external oblique muscle. The internal oblique muscle originates from the iliac crest and the lateral side of the inguinal ligament and diffuses while running orthogonal to the external oblique muscle bundle. The muscular part of the muscle extends closer to the rectus abdominis muscle than does the external oblique muscle or the underlying transverse abdominis muscle and forms a bow-shaped free lower border above the spermatic cord, creating the upper wall (ceiling) of the inguinal canal. The lateral end of the attachment of the free lower border is located even more lateral to the triangular defect of the external oblique aponeurosis;

this “displacement” is actually the essence of the inguinal canal. A part of the muscle bundle extends like a tongue and spreads as a thin membrane wrapping around the spermatic cord. This is the cremaster muscle The narrow aponeurotic part of the internal oblique muscle immediately splits into the anterior and posterior leaves, which become the anterior and posterior walls of the rectus sheath, respectively. The lower part of the posterior sheath is defective and its lower border represents the arcuate line. The area below the arcuate line on the posterior side of the rectus abdominis muscle is where the fascia transversalis will directly attach to

19  Anatomy of the Inguinal Canal and Surrounding Structures

484

Conjoint tendon Aponeurotic arch of transversus abdominis m.

Free lower border of internal oblique m.

Transversus m.

Subperitoneal fascia

Fascia transversalis

Femoral sheath

Fig. 19.3  Further attached to the underside of the internal oblique muscle is the transversus abdominis muscle. The muscle bundle of the transversus abdominis is oriented horizontally, although it has already become aponeurotic by the time it reaches the upper part of the inguinal canal. Its lower border also forms an arch and reinforces the corresponding part of the internal oblique muscle from behind, forming the “conjoint tendon.” This is referred to as the aponeurotic arch of the transversus abdominis, but it is structurally difficult to identify from the body surface side. As the aponeurotic arch is almost consistent with the free lower border of the internal oblique muscle, the area bordered by the conjoint tendon (arch) and the inguinal ligament (string) is the weakest part of the abdominal wall,

with no muscle or aponeurosis. This is not because of incomplete development, but rather is a necessary consequence to allow for passage of the spermatic cord. The fascia transversalis, which is to be attached in the next step, is a “lining tissue” that is tightly attached to muscle (aponeurosis) and bone while surrounding the entire abdominal cavity, and in this area, it bears the heavy responsibility of independently supporting the abdominal organs from below. Because the presence of this fascia alone seems inadequate, the aponeurotic fibers of the transversus abdominis are partially dispersed and spread as a thin membrane to reinforce this fascia transversalis (see Fig. 19.5). Having fewer commingled fibers increases the risk of internal inguinal (direct) hernia

19  Anatomy of the Inguinal Canal and Surrounding Structures

485

Fascia transversalis Abdominal cavity side Body surface side

l

Inf. epigastric a. & v.

Media

al

Later

Line of conjoint tendon Sling of fascia transversalis

Interfoveolar lig. Triangle of Hesselbach

Subperitoneal fascia Deep inguinal ring

Femoral canal

Iliopubic tract

Preperitoneal space Preperitoneal fat

Femoral ring

Fig. 19.4  The “page” of the fascia transversalis, the most important structure for understanding the local anatomy of the inguinal region, is flipped and glued to the transversus muscle. There is cord-like thickening of the fascia transversalis parallel to the inguinal ligament, known as the iliopubic tract. The iliopubic tract is connected to the inguinal ligament by the innominate fascia. Beyond the iliopubic tract, the fascia transversalis attaches to the superior pubic ramus while spreading like a fan and covering the ligament of Cooper. Around the vascular lacuna, the fascia cylindrically protrudes by several centimeters while wrapping around the femoral artery and vein, forming the femoral sheath (see Figs. 19.3 and 19.5). During this process, a cone-shaped gap is formed between the femoral vein and the femoral sheath, housing a lymphatic duct, lymph nodes, and fat tissue. This gap is the femoral canal (arrow). The entrance to the femoral canal is referred to as the femoral ring, which serves as the hernial orifice in femoral hernia The part of the fascia transversalis corresponding to the area bordered by the conjoint tendon and the inguinal ligament (nonglued area) is forced to serve as the posterior wall of the inguinal canal, resisting the intraabdomi-

nal pressure. In this area, a thickened band arises from the midpoint of the iliopubic tract and vertically divides the posterior wall into two parts. This is the interfoveolar ligament and it serves as the base on which the inferior epigastric artery and vein are mounted. The part of the fascia transversalis medial to the interfoveolar ligament lines the triangle of Hesselbach triangle, the hernial orifice of an internal inguinal hernia. The part of the fascia lateral to the ligament protrudes progressively as the peritoneal recess formed in this area deepens, as if wrapping around the recess (see Fig. 19.5). The origin of the protrusion is referred to as the deep inguinal ring and it serves as the hernial orifice of an external inguinal (indirect) hernia. The deep inguinal ring has a V-shaped thickening that resembles the crus of the diaphragm surrounding the esophageal hiatus and is referred to as the sling of fascia transversalis. In response to increased intraabdominal pressure, the crus of the sling is closed by a shutter mechanism to prevent the development of external inguinal hernia. The interfoveolar ligament and the sling represent the maximum effort made by the fascia transversalis, which was surprisingly assigned the responsibility of supporting the abdominal organs

19  Anatomy of the Inguinal Canal and Surrounding Structures

486 Int. oblique m.

Fascia transversalis (abdominal cavity side) Free lower border of internal oblique m.

Ext. oblique m. Inf. epigastric a. & v.

Fascia transversalis (body surface side) Cremaster m. Aponeurotic arch of transversus abdominis m. Aponeurotic fibers of transversus abdominis m. spreading over surface of fascia transversalis

Deep inguinal ring Int. spermatic fascia Aponeurosis

Superficial inguinal ring

Femoral sheath

Inguinal lig. Femoral a. & v.

Iliopubic tract Ligament of Cooper

Femoral canal

Lacunar lig.

Fig. 19.5  Now that the fascia transversalis has been attached, all of the members that constitute the inguinal canal are in place. Before flipping the pages of the preperitoneal space and the peritoneum, let us review the parts assembled so far from the outside of the abdominal wall The “anterior wall” of the inguinal canal consists of the aponeurosis of the external oblique muscle and intercrural fibers; the “upper wall” consists of the conjoint tendon formed by the free lower border of the internal oblique muscle and the aponeurotic arch of the transversus muscle; the “posterior wall” consists of the fascia transversalis and part of the aponeurotic fibers of the transversus muscle; and the “lower wall” consists of the inguinal ligament. The free lower border of the internal

oblique muscle is slid upward in the figure to help understand that the free lower border forms the upper wall of the inguinal canal. From this figure, we can see that the “displacement” between the defect of the external oblique aponeurosis and the conjoint tendon creates the inguinal canal and enables the deep and superficial inguinal rings to be positioned in a “ ” shape. Note that this “displacement” increases with physical growth, so the deep inguinal ring in neonates is located immediately posterior to the superficial inguinal ring, forming a short inguinal canal. The part of the fascia transversalis that protrudes like a finger cot is now referred to as the internal spermatic fascia and covers the spermatic cord. This is further wrapped around by the cremaster muscle, which is a part of the internal oblique muscle bundle

19  Anatomy of the Inguinal Canal and Surrounding Structures Lat. umbilical fold

487 Peritoneum

Med. umbilical fold Med. umbilical fold Fascia transversalis

Med. inguinal fossa

Lat. inguinal fossa

Testicular a. & v. (folds) Peritoneum

Preperitoneal space

Ext. iliac a. & v. Femoral fossa

Vas deferens (folds)

Fig. 19.6  Finally, the preperitoneal space and the peritoneum are attached. The preperitoneal space, which is also mentioned in Chap. 1 on the anatomy of the stomach and Chap. 8 on the anatomy of the large intestine, has a three-­ layered structure where the intermediate fat layer (❶) is sandwiched between two thin layers of subperitoneal fascia (❷). Although due to its structure we might feel uncomfortable to call it a “space,” the fat layer is much looser and softer than subcutaneous fat. As described in Chap. 1, the term “preperitoneal space” is based on the observation from the body surface side and the same space is called the “retroperitoneal space” when viewed from within the abdominal cavity. Similarly, the soft fat issue referred to as “preperitoneal fat” in this chapter is called “extraperitoneal fat” when viewed from within the abdominal cavity. The preperitoneal space allows for passage of the vas deferens, testicular artery and vein, lateral umbilical ligament (remnant of the umbilical artery connected to the superior vesical artery), and the median umbilical ligament (remnant of the urachus). Along the lateral and median umbilical ligaments are cord-like bulgings of the peritoneum referred to as the medial and median umbilical folds, respectively. The inferior epigas-

tric vessels, which are connected to the external iliac vessels, do not pass through the preperitoneal space but pass in front of the fascia transversalis, which is the next shallower layer when viewed from the body surface (see Fig. 19.4). Along these vessels is also a cord-like bulging of the peritoneum referred to as the lateral umbilical fold. The part of the peritoneum lateral to the lateral umbilical fold corresponding to the deep inguinal ring forms a recess, the lateral inguinal fossa, which is where external inguinal hernia develops. On the medial side of the lateral umbilical fold, the part of the peritoneum corresponding to the triangle of Hesselbach also forms a recess, the medial inguinal fossa, which is where internal inguinal hernia develops. The inferior epigastric vessels form a partition between the internal and external inguinal fossae, which can be a useful landmark for distinguishing between external and internal inguinal hernias. The parts of the peritoneum lining the femoral ring also form a recess, the femoral fossa, which is where femoral hernia develops. Because these three fossae are located close to each other and serve as the orifices for all types of hernia occurring in the inguinal region, they are collectively referred to as the “myopectineal orifice of Fruchaud”

19  Anatomy of the Inguinal Canal and Surrounding Structures

488

Preperitoneal space

Peritoneum

Inf. epigastric a. & v.

Fascia transversalis

Ext. inguinal hernia Interfoveolar lig.

Lat. umbilical lig. Med. umbilical lig.

Int. inguinal hernia

Aponeurotic arch of transversus abdominis m. Int. oblique m. Cremaster m.

Rectus sheath

Ext. oblique aponeurosis Ext. spermatic fascia

Vas deferens Gonadal a. & v.

Int. spermatic fascia

Testis Vestigial processus vaginalis peritonei

Tunica vaginalis

Visceral laminae

Scrotal cavity

Parietal laminae

Fig. 19.7  Structure of inguinal hernia in a cross section of the spermatic cord: During fetal life, when the testis that forms in the extraperitoneal fat tissue (preperitoneal fat tissue) of the retroperitoneal space (preperitoneal space) begins its descent, a peritoneal recess is formed at the susceptible part of the abdominal wall lateral to the interfoveolar ligament. This recess gradually deepens while acquiring, but not rupturing, the layers constituting the preperitoneal space [preperitoneal fat tissue (❶) + two thin layers of subperitoneal fascia (❷)] and the fascia transversalis (❸), that is, while being wrapped around by this multilayer structure, and extends into the inguinal canal. This structure is referred to as the “processus vaginalis” (the term “processus vaginalis peritonei” indicates only its peritoneal component). After confirming that the processus vaginalis has reached the scrotum, the testis, guided by the gubernaculum, descends gradually within the preperitoneal fat layer (❶) from which it originally arises, accompanied by the vas deferens and testicular vessels, until it reaches its final position at the lower end of the processus vaginalis. This path is always located posterior to (on the abdominal wall side of) the processus vaginalis, either inside the inguinal canal or in the scrotum. After the passage of the testis, this “processus vaginalis with a multi-layered wall containing the vas deferens and testicular vessels” becomes the “spermatic cord.” The spermatic cord is covered by a fascia that is continuous with the fascia transversalis (❸) arising from

the deep inguinal ring, that is, the internal spermatic fascia (❸′). While passing through the inguinal canal, the spermatic cord also acquires a part of the muscle bundle forming the lower border of the internal oblique muscle and takes it away. This becomes the cremaster muscle (❹), which further wraps around the spermatic cord and forms its outermost layer. Once out of the inguinal canal, the spermatic cord is sequentially covered by the external spermatic fascia (continued from the external oblique aponeurosis; ❺), which it acquired while passing through the superficial inguinal ring, the dartos muscle continuous with the subcutaneous superficial fascia, and the scrotal skin The innermost layer of the spermatic cord is, needless to say, the peritoneum, which persists as the tunica vaginalis testis only at the tip of the cord and degrades or disappears in other parts. Any persistent peritoneum can form a hernia sac of pediatric external inguinal hernia. The residual tunica vaginalis forms the scrotal cavity, which is composed of the visceral and parietal laminae and filled with serous fluid. In certain conditions, the scrotal cavity is filled with pathological serous effusion and is distended, and this is referred to as hydrocele The hernia sacs in adult external inguinal hernia (black arrow) and internal inguinal hernia (white arrow) are formed by sac-like extensions of the peritoneum at the external and internal inguinal fossae, respectively, with the layers of the preperitoneal space remaining intact

19  Anatomy of the Inguinal Canal and Surrounding Structures

489

Aponeurotic arch of transversus abdominis m. Int. epigastric a. & v.

Int. spermatic fascia Cremaster m. Peritoneum Internal spermatic fascia Peritoneum

Preperitoneal space Fascia transversalis

Peritoneum Femoral sheath

Small intestine

Fig. 19.8  The right abdominal wall again viewed from the body surface side, showing the three-dimensional structure of external inguinal hernia. The spermatic cord is surrounded by two layers: the cremaster muscle (❹) derived from the internal oblique muscle and the internal spermatic fascia (❸′) derived from the fascia transversalis. Between the hernia sac formed by a stretched peritoneum and the internal spermatic fascia are preperitoneal fat tissue (❶) and two thin layers of subperitoneal fascia (❷). The vas deferens and testicular vessels course through the preperitoneal fat layer on the abdominal wall

side. The femoral sheath (❸″), which appeared earlier (Fig. 19.4), is also formed by the cylindrical extension of the fascia transversalis (❸), just like the internal spermatic fascia In women, ovarian descent stops when a part of the gubernaculum attaches to the uterus. The part of the gubernaculum between the uterine wall and the labium majus persists as the round ligament of uterus, and the structures corresponding to the internal spermatic fascia (❸′), cremaster muscle (❹), and external spermatic fascia (❺) in men all become the capsule of the ligament

19  Anatomy of the Inguinal Canal and Surrounding Structures

490

a

Inf. epigastric a. & v.



Vas deferens

Hernia sac (blind end)

Gonadal a. & v.

* Inverted hernia sac

b

Plug

Onlay mesh Slit

 

19  Anatomy of the Inguinal Canal and Surrounding Structures

Fig. 19.9  Here, we look at the typical procedures for repairing external inguinal hernia, using the same cross-­ sectional diagram as that in Fig. 19.7 The part of the spermatic cord indicated by an asterisk in (a) is the normal structure. It has a folded double structure like folded strata of earth and consists of, in the order of encounter when entering from the outermost layer through the core and then out through the other side of the cord, the following 11 layers in total: the cremaster muscle, internal spermatic fascia (❸′), subperitoneal fascia (❷), preperitoneal fat tissue (❶), subperitoneal fascia (❷), vestigial processus vaginalis peritonei, subperitoneal fascia (❷), preperitoneal fat tissue containing the vas deferens and testicular vessels (❶), subperitoneal fascia (❷), internal spermatic fascia (❸′), and cremaster muscle Higher ligation (a): First, the cremaster muscle (❹) is cut off from the free lower border of the internal oblique muscle and the spermatic cord is circumferentially isolated inside the inguinal canal. After the internal spermatic fascia (❸′) is circumferentially incised at the origin of the spermatic cord to open the deep inguinal ring, the two layers of the subperitoneal fascia (❷) are incised so that the hernia sac can be reached. The hernia sac is then tran-

491

sected and ligated, leaving only the vas deferens and testicular vessels exposed Mesh plug repair (b): A plug is inserted while inverting the hernia sac. After the vas deferens and gonadal vessels are allowed to pass through the slit of an onlay mesh, the mesh is placed in front of the plug and the fascia transversalis (❸) to reinforce the posterior wall Repair using the Prolene Hernia System (c): After ligation of the hernia sac, the peritoneum and the subperitoneal fascia (❷) of the preperitoneal space are separated to create a wide gap. A connector is placed in the deep inguinal ring and an underlay patch is inserted into the gap created. This patch is located deeper than the inferior epigastric vessels and vas deferens and testicular vessels. The vas deferens and testicular vessels are allowed to pass through a slit created on the onlay patch, and then the patch is placed in front of the fascia transversalis (❸) to reinforce the posterior wall Direct Kugel repair (d): As for Prolene Hernia System repair, the peritoneum and subperitoneal fascia (❷) of the preperitoneal space are separated broadly to create a gap and an underlay patch is inserted into the gap. In this figure, the hernia sac is inverted into the abdominal cavity without being transected

19  Anatomy of the Inguinal Canal and Surrounding Structures

492

c

Ligated hernia sac Underlay patch Peritoneum

Connector Onlay patch

d

Inverted hernia sac Underlay patch Peritoneum

Fig. 19.9 (continued)

19  Anatomy of the Inguinal Canal and Surrounding Structures

493

Fascia transversalis

Int. spermatic fascia Iliopubic tract Inguinal lig. Lacunar lig

Femoral sheath

Small intestine

Hernia sac (peritoneum)

Fig. 19.10  Structure of a femoral hernia. While covered by the stretched femoral sheath (❸″) and subperitoneal fascia (❷), the hernia sac (peritoneum) passes through the femoral canal into the fossa ovalis. Because the femoral ring that serves as the hernia orifice is composed of the robust inguinal and lacunar ligaments, the hernia tends to

be incarcerated. When the hernia contents cannot be pushed back into the abdominal cavity, we need either to widen the femoral canal by incising the lacunar ligament or, if that is not sufficient, to open the femoral canal by also incising the inguinal ligament

Repair of Inguinal Hernia: Mesh Plug

Abstract

Just like with film production, several staff members participate in an operation, such as anesthesiologists, instrument and circulating nurses, and surgeons. If we think of the lead actor of an operation as the operating surgeon, then the role of the movie director—who gives the lead actor detailed instructions on movement, controls the overall progress, and prepares a comfortable work environment for everyone participating while paying attention to the surroundings—should, I believe, be played by the first assistant. Even in small operations such as inguinal hernia repair, the role expected of the first assistant is always the same: to maintain a good operative field. In

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this operation especially, we can see impressive multilayered fascial structures. The surgeon can enjoy the procedure by dissecting the layers wrapping around the spermatic cord one by one while also thinking about how the cord was formed during fetal life. Due to very few anatomical variations, we can be confident in performing this operation after performing several procedures carefully supervised by senior surgeons. This chapter describes a repair procedure using a mesh plug. The operation time is about 40 min. Keywords

Operating surgeon · First assistant · Mesh plug · Inguinal hernia repair

© Springer Nature Singapore Pte Ltd. 2020 H. Shinohara, Illustrated Abdominal Surgery, https://doi.org/10.1007/978-981-15-1796-9_20

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496

Sup. epigastric v.

Fig. 20.1  From the midpoint of a line connecting the anterior superior iliac spine and the superficial inguinal ring, a skin incision about 6 cm long is made medially along the line of Langer

Sup. epigastric v.

Fig. 20.2  The first assistant expands the wound with two flat retractors. The superficial epigastric vein is usually encountered as it crosses the wound. The vein should be

coagulated with electrocautery if it is thin, or ligated and divided if it is thick

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497

Fig. 20.3  Two thin layers of the superficial fascia must be passed before reaching the external oblique aponeurosis. The dissection should then continue by picking them up with hooked forceps and dividing them with a scalpel

Superficial fascia

Medial crus

Aponeurosis of ext. oblique m.

Sup. inguinal ring Lateral crus

Spermatic cord (ext. spermatic fascia)

Inguinal lig.

Fig. 20.4  After exposing the pearl-colored fibers of the external oblique aponeurosis, the operative field should be expanded adequately with retractors. The triangle formed between the lateral crus and medial crus (covered by the intercrural fiber, through which the brownish cremaster muscle can be seen) and the superficial inguinal ring

(located on the line extended from the triangle) should be identified accurately. If we fail to do this, we will get lost in a maze. Within the triangle, a small incision is made along the fibers of the external oblique aponeurosis. The incision should be shallow enough to avoid damaging the nerves and vessels in the spermatic cord

20  Repair of Inguinal Hernia: Mesh Plug

498 Fig. 20.5  The edge of the incision is grasped with Pean forceps. For easy grasping, try inserting the forceps into the incision and open them while lifting up, which lifts the aponeurosis from the spermatic cord

Cremaster m.

Fig. 20.6  The incision is extended with Mayo scissors along the direction of the fibers up to the vicinity of the deep inguinal ring and grasped with another pair of Pean forceps. During this procedure, be careful not to damage the ilioinguinal nerve coursing immediately below the aponeurosis (Fig. 20.8)

Medial crus

Lateral crus

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499

Fig. 20.7  The incision is then also advanced toward the outlet for the spermatic cord. The external spermatic fascia, which continues from the superficial inguinal ring, is partially incised to open the inguinal canal completely. This exposes the cremaster muscle covering the surface of the spermatic cord

Sup. inguinal ring

Ext. spermatic fascia

Cremaster m.

Spermatic cord (Int. spermatic fascia)

Ilioinguinal n.

Fascia transversalis

Inguinal lig.

Fig. 20.8  Now the spermatic cord is isolated. First, the cord is detached from the lower wall of the inguinal canal. The spermatic cord is bluntly detached from the external oblique aponeurosis and the inguinal ligament with the tip of Cooper scissors. Usually, the cord can be detached eas-

ily with no adhesions. The dissection should advance beyond the pearl-colored inguinal ligament until reaching the fascia transversalis that forms the posterior wall of the inguinal canal. This helps with the later lifting of the spermatic cord

20  Repair of Inguinal Hernia: Mesh Plug

500 Fig. 20.9  Next, the cord is detached from the upper wall of the inguinal canal. On this side, unlike the lower wall side, the spermatic cord is linearly connected to the internal oblique muscle via the cremaster muscle. The internal oblique muscle is exposed widely by applying force to the tip of the proximal flat retractor, and the junction with the cremaster muscle is divided with electrocautery. (The internal oblique muscle should be exposed at this point because it will be needed later for onlay mesh insertion)

Int. oblique m.

Cremaster m.

Pubic tubercle

Fig. 20.10  After detaching the spermatic cord from the upper and lower walls, the index finger is slid under the cord. For an external inguinal hernia, the cord will be thickened by the presence of the hernia sac, so the index finger should be inserted deep enough to be scooped the entire cord. For an internal inguinal hernia, a loosened

posterior wall (fascia transversalis) means that it is difficult to find the correct route to insert the index finger. Also, note that inserting the finger too deeply can damage the hernia sac. To be safe in either case, insert the index finger along the pubic tubercle

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501

Cremaster m. Int. spermatic fascia

Ilioinguinal n.

Fascia transversalis

Fig. 20.11  The inserted finger is then slid horizontally to thoroughly detach the spermatic cord from the posterior wall. A pair of Kelly forceps is then passed under the cord, guided by the finger, to grasp a thin Nelaton catheter with its tip and pull it out. The catheter is formed into a loop

and grasped with Kocher forceps. The detached spermatic cord is surrounded by the cremaster muscle and the internal spermatic fascia, which continues from the fascia transversalis and is mounted by the ilioinguinal nerve

20  Repair of Inguinal Hernia: Mesh Plug

502 Fig. 20.12  With the spermatic cord lifted using the Nelaton catheter, the residual fibrous connective tissue between the cord and the posterior wall is dissected to complete spermatic cord isolation. Proceeding with the dissection up to the vicinity of the deep inguinal ring enables us to identify the inferior epigastric vessels. For an internal inguinal hernia, the hernia sac can be seen at this point

Inf. epigastric a. & v.

Fascia transversalis

Vas deferens and gonadal a. & v.

Fascia transversalis

Fig. 20.13  Handling of a large hernia sac (Figs. 20.13– 20.20): In mesh plug repair, the hernia sac is usually not resected and inverted into the abdominal cavity. However, a large hernia sac that protrudes beyond the midpoint of the inguinal canal should be transected at an appropriate point. The standard procedure is to identify the hernia sac around the midpoint of the spermatic cord and detach it from the cord. To reach the hernia sac (Ⓢ) from the surface of the spermatic cord, we need to pass through the cre-

master muscle (❹), internal spermatic fascia (❸′), and the two thin layers of the subperitoneal fascia (❷)in that order. Using two pairs of hooked forceps, these structures are sequentially identified and divided, and a whitish hernia sac is withdrawn from underneath them. The surgeon asks the first assistant to make a small incision on the sac and examine the inside. The hernia sac can either be identified at a glance by its whitish thickened wall or it may have a thin wall that makes it difficult to identify

20  Repair of Inguinal Hernia: Mesh Plug

Fig. 20.14  Grasping the edge of the incised opening with two pairs of Pean forceps, the incision is extended proximally and distally with Mayo scissors. Proximally, only a short incision should be made, and the edge grasped

503

with Pean forceps. In contrast, the distal incision should be extended as far as it can be, even up to the blind end if it can be identified

Fig. 20.15 Appearance of the hernia sac (Ⓢ) after it has been opened. ❸′, internal spermatic fascia

Ab ca do vit mi y n

al

Bl en ind d

504

Fig. 20.16  Transection of the hernia sac (the subsequent procedures are not necessary if the sac forms a blind end in the inguinal canal): The hernia sac is transected while being supported with three pairs of Pean forceps. Forceps ② and ③ are applied first. Forceps ④ is also applied on the transection line to minimize the cutting distance. While

Fig. 20.17 Forceps ⑤ is applied and the hernia sac is detached and divided while being supported with forceps ③, ④, and ⑤

20  Repair of Inguinal Hernia: Mesh Plug

applying countertraction with forceps ①, ②, and ③, Mayo scissors are slid under the sac to cut just the sac while detaching the other tissues, such as the vas deference and blood vessels. For better handling of scissors, it is advisable to use the “open while advancing” technique

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505

Fig. 20.18 Finally, forceps ⑥ is applied and the transection of the hernia sac is complete. The forceps applied to the distal part of the sac are removed, leaving that part of the sac as it is

Fig. 20.19  The hernia sac is then detached from the spermatic cord toward the deep inguinal ring. Lifting the sac up with the left index finger inserted into the sac, tissues surrounding the sac (the layers of the preperitoneal space, including the preperitoneal fat tissue containing the vas deferens and testicular vessels ❶ and the subperitoneal fascia ❷) are peeled off with Cooper scissors. This should be done carefully to avoid damaging the vas deferens or blood vessels or perforating the sac. The first assistant pulls the spermatic cord downward to apply tension to the dissected part

Vas deferens

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506 Fig. 20.20  As the hernia sac is lifted from the spermatic cord, the internal spermatic fascia and the subperitoneal fascia covering the cord are spontaneously torn longitudinally. Continuing this procedure ends up reaching the junction with the fascia transversalis, that is, the deep inguinal ring. Detachment of the hernia sac is complete when the prominent hump of the preperitoneal fat tissue is exposed at the root of the sac. The hernia sac is divided far enough from the root for the later insertion of a plug and inversion of the sac (about 3 cm). The proximal stump is closed by piercing ligation with a 3-0 Vicryl suture

1

Ⓢ

Preperitoneal fat tissue

3

′

Ⓢ Distal stump of hernia sac

3

2

Inf. epigastric a. & v.

Fig. 20.21  Handling of a small hernia sac (Figs. 20.21–20.24): In the case of a mild hernia, we need to explore the vicinity of the deep inguinal ring to identify the hernia sac. But we must be careful because damaging the hernia sac at this level could cause us to get lost in a maze and make repair difficult. So, we need to proceed with the dissection carefully while accurately identifying each layer. First, the outermost cremaster muscle is scooped superficially with dissection forceps along the short axis of the muscle and divided with electrocautery. (If identifiable, the ilioinguinal nerve coursing over the cremaster muscle should be preserved whenever possible)

Inf. oblique m.

4

Cremaster m.

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507

2

3 2

3

3

3

′

′

4

Hernia contents (small intestine)

Fig. 20.22  The next step is to circumferentially incise the internal spermatic fascia (❸′) where it arises from the fascia transversalis (❸). This is just like making a circumferential cut into the vinyl sheath of a coaxial cable leading to an antenna. This makes a round opening on the

fascia transversalis along the deep inguinal ring and exposes the inferior epigastric vessels inside the ring. A longitudinal incision is also made along the long axis of the spermatic cord on the internal spermatic fascia up to the midpoint of the cord

20  Repair of Inguinal Hernia: Mesh Plug

508 Fig. 20.23  At this point, the outermost layer of the spermatic cord is the superficial subperitoneal fascia (❷). By incising this membrane, we can enter the space that continues from the preperitoneal space and this reveals the preperitoneal fat tissue (❶). As the incision continues, the vas deferens and testicular vessels are also exposed. By this time, a white hernia sac Ⓢ that is distinct from other membranes can be seen transparently. The hernia sac is overlaid by another (deep) layer of the subperitoneal fascia (❷). Once the sac is identified, a part of the sac is grasped together with the subperitoneal fascia using Pean forceps and pulled up. ❸′, internal spermatic fascia; ❹, cremaster muscle

Fig. 20.24  The hernia sac (Ⓢ) is then lifted from the spermatic cord by peeling off the deep subperitoneal fascia covering the sac (❷) with Cooper scissors. If the hernia sac is firmly adherent to the subperitoneal fascia, we must be careful to avoid forcibly detaching the fascia, which risks damaging the sac. All we need to do is separate the hernia sac from the vas deferens and testicular vessels so that it can be inverted properly. However, when we plan to repair using the Prolene Hernia System or a direct Kugel repair, we must peel off all layers other than the peritoneum from the hernia sac so that we can correctly enter the preperitoneal space (the gap between the peritoneum and the subperitoneal fascia), into which an underlay patch will be inserted

4

3 2

′

(Deep layer) 2

Space continuing from preperitoneal space

Gonadal a. & v. Vas deferens 1

3

2

Inf. epigastric a. & v.

Deep inguinal ring

3 2

2

(Deep layer) 1 3

2

′

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a

2

509

b

(Deep layer) 1 2 3

(Deep layer)

Plug

Inverted hernia sac

c

Fig. 20.25  The isolated hernia sac is then inverted into the abdominal cavity (a) and a plug is inserted into the inverted sac (b). The fascia transversalis around the deep inguinal ring and the plug are fixed by using two 3-0 Vicryl sutures (c)

20  Repair of Inguinal Hernia: Mesh Plug

510 Fig. 20.26  Plug insertion for internal inguinal hernia: An internal inguinal hernia should be suspected when, after the spermatic cord has been isolated and lifted up, the posterior wall of the inguinal canal appears loose and fragile and the spermatic cord appears thinner than usual. Also in this case, the deep inguinal ring should be incised by following the procedure in Figs. 20.21–20.23 to confirm the absence of a hernia sac lateral to the inferior epigastric vessels. Then, the fascia transversalis is cut off the periphery of the deep inguinal ring by making an incision parallel to the inguinal ligament (a). After identifying the hernia sac medial to the inferior epigastric vessels, the sac is inverted into the abdominal cavity and a plug is inserted into the inverted sac. The edge of the fascia transversalis and the plug are fixed using several 3-0 Vicryl sutures (b). The incised deep inguinal ring should be repaired by applying two sutures to the fascia transversalis, one at the medial end and the other at the lateral end of the ring. We may also encounter cases of internal inguinal hernia where the entire posterior wall of the inguinal canal has become a hernial orifice and there is no “sac” into which a plug can be inserted. ❸, fascia transversalis

a

3

b

Sutured inguinal ring

Plug

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Fig. 20.27 Placement of onlay mesh: After the vas deferens and testicular vessels are passed through the slit on the mesh, the slit is closed with two 3-0 Vicryl sutures

Fig. 20.28  The mesh is spread over the posterior wall of the inguinal canal, with the cranial side oriented in front of the internal oblique muscle. To prevent the mesh from displacing, its upper and lower corners are anchored to the internal oblique muscle and the inguinal ligament, respectively, using 3-0 Vicryl sutures

Int. oblique m.

Inguinal lig.

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Fig. 20.29 After several additional sutures are applied to the internal oblique muscle and the inguinal ligament for mesh fixation, the excess portion on the lower end of the mesh on the pubic tubercle is cut off

Pubic tubercle

Fig. 20.30 The inguinal ligament fuses with the periosteum covering the upper border of the superior pubic ramus (the ligament of Cooper) to form the lacunar ligament and is attached to the pubic tubercle (see Fig. 19.1 on the anatomy of the inguinal canal and surrounding structures). The lower end of the mesh is firmly fixed to the lacunar ligament with two to three sutures. This is the most important procedure in preventing postoperative recurrence

Pubic tubercle

Lacunar lig.

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513

Fig. 20.31  The testis is pulled down to stretch the spermatic cord. The external oblique aponeurosis is repaired using 3-0 Vicryl sutures

inguinal lig.

Sup. inguinal ring

Fig. 20.32 The superficial fascia is closed with two 3-0 Vicryl sutures and the skin is suture-closed to complete the operation

Superficial fascia

Bibliography

1. Shinohara H, Kurahashi Y, Haruta S, Ishida Y, Sasako M. Universalization of the operative strategy by systematic mesogastric excision for stomach cancer with that for total mesorectal excision and complete mesocolic excision colorectal counterparts. Ann Gastroenterol Surg. 2018;2:28–36. 2. Sadler TW. Langman’s medical embryology. 11th ed. Philadelphia: Lippincott Williams & Wilkins; 2009. 3. Moore KL, Persaud TVN, Torchia MG. The developing human: clinically oriented embryology. 8th ed. Philadelphia: Saunders/Elsevier; 2008. 4. Kawaguchi Y, Cooper B, Gannon M, et  al. The role of the transcriptional regulator Ptf1a in converting intestinal to pancreatic progenitors. Nat Genet. 2002;32:128–34. 5. Nakamura T, Yamada S, Funatomi T, Takakuwa T, Shinohara H, Sakai Y. Three-dimensional morphogenesis of the omental bursa from four recesses in staged human embryos. J Anat. 2020. Epub (https://doi.org/10.1111/joa.13174). 6. Kumamoto T, Kurahashi Y, Haruta S, Niwa H, Nakanishi Y, Ozawa R, Okumura K, Ishida Y, Shinohara H.  Laparoscopic modified lymphadenectomy in gastric cancer surgery using systematic mesogastric excision: a novel technique based on a concept. Langenbeck’s Arch Surg. 2019;404:369–74. 7. Shinohara H, Kurahashi Y, Kanaya S, Haruta S, Ueno M, Udagawa H, Sakai Y.  Topographic anatomy and laparoscopic technique for dissection of no. 6 infrapyloric lymph nodes in gastric cancer surgery. Gastric Cancer. 2013;16:615–20. 8. Shinohara H, Haruta S, Ohkura Y, Udagawa H, Sakai Y.  Tracing dissectable layers of mesenteries overcomes embryologic restrictions when performing infrapyloric lymphadenectomy in laparoscopic gastric cancer surgery. J Am Coll Surg. 2015;220:e81–7. 9. Kobayashi N, Shinohara H, Haruta S, Ohkura Y, Mizuno A, Ueno M, Udagawa H, Sakai Y. Process of pancreas head as a risk factor for postoperative pancreatic fistula in laparoscopic gastric cancer surgery. World J Surg. 2016;40:2194–201. 10. Haruta H, Shinohara H, Ueno M, Udagawa H, Sakai Y, Uyama I. Anatomical considerations of the infrapyloric artery and its associated lymph nodes during

laparoscopic gastric cancer surgery. Gastric Cancer. 2015;18:876–80. 11. Mizuno A, Shinohara H, Haruta S, Tsunoda S, Kurahashi Y, Ohkura Y, Udagawa H, Sakai Y.  Lymphadenectomy along the infrapyloric artery may be dispensable when performing pylorus-­ preserving gastrectomy for early middle-third gastric cancer. Gastric Cancer. 2017;20:543–7. 12. Nakamura T, Shinohara H, Okada T, Hisamori S, Tsunoda S, Obama K, Kurahashi Y, Takai A, Shimokawa T, Matsuda S, Makishima H, Takakuwa T, Yamada S, Sakai Y.  Revisiting the infracardiac bursa using multimodal methods: topographic anatomy for surgery of the esophagogastric junction. J Anat. 2019;235:88–95. 13. Hohenberger W, Weber K, Matzel K, Papadopoulos T, Merkel S.  Standardized surgery for colonic cancer: complete mesocolic excision and central ligation—technical notes and outcome. Color Dis. 2009;11:354–64. 14. Culligan K, Sehgal R, Mulligan D, Dunne C, Walsh S, Quondamatteo F, Dockery P, Coffy JC. A detailed appraisal of mesocolic lymphangiology—an immunohistochemical and stereological analysis. J Anat. 2014;225:463–72. 15. Heald RJ, Husband EM, Ryall RDH. The mesorectum in rectal cancer surgery: the clue to pelvic recurrence? Br J Surg. 1982;69:613–6. 16. Kinugasa Y, Murakami G, Suzuki D, Sugihara K. Histological identification of fascial structures posterolateral to the rectum. Br J Surg. 2007;94: 620–6. 17. Sakai Y, Hasegawa S, Shinohara H, Yamada M, Okada M. Laparoscopic total mesorectal excision (TME) for rectal cancer. In: Sakai Y, editor. Laparoscopic surgery for colorectal cancer. Japan: Springer; 2016. p. 109–35. 18. Heald RJ, Moran BJ, Brown G, Daniels IR. Optimal total mesorectal excision for rectal cancer is by dissection in front of Denonvilliers’ fascia. Br J Surg. 2004;91:121–3. 19. Couinaud C. Lobes et segments héatiques: Notes sur l’architectune anatomique et chirurgicale due foie. Presse Méd. 1954;62:709–11.

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