Technical Variations and Refinements in Head and Neck Surgery [1 ed.] 9789386107619, 9789351523178

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Technical Variations and Refinements in

Head and Neck Surgery

Technical Variations and Refinements in

Head and Neck Surgery

Luc GT Morris MD MSc Catherine and Frederick R Adler Chair for Junior Faculty Assistant Attending Surgeon Head and Neck Service Memorial Sloan-Kettering Cancer Center Assistant Professor of Otolaryngology Weill Medical College of Cornell University New York, NY, USA Jatin P Shah MD PhD(Hon) FACS FRCS(Hon)     FDSRCS(Hon) FRACS(Hon)

Chief, Head and Neck Service EW Strong Chair in Head and Neck Oncology Memorial Sloan-Kettering Cancer Center Professor of Surgery Weill Medical College of Cornell University New York, NY, USA

JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD Philadelphia • New Delhi • London • Panama

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Website: www.jaypeebrothers.com Website: www.jaypeedigital.com © 2014, Jaypee Brothers Medical Publishers The views and opinions expressed in this book are solely those of the original contributor(s)/author(s) and do not necessarily represent those of editor(s) of the book. All rights reserved. No part of this publication may be reproduced, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission in writing of the publishers. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. Medical knowledge and practice change constantly. This book is designed to provide accurate, authoritative information about the subject matter in question. However, readers are advised to check the most current information available on procedures included and check information from the manufacturer of each product to be administered, to verify the recommended dose, formula, method and duration of administration, adverse effects and contraindications. It is the responsibility of the practitioner to take all appropriate safety precautions. Neither the publisher nor the author(s)/ editor(s) assume any liability for any injury and/or damage to persons or property arising from or related to use of material in this book. This book is sold on the understanding that the publisher is not engaged in providing professional medical services. If such advice or services are required, the services of a competent medical professional should be sought. Every effort has been made where necessary to contact holders of copyright to obtain permission to reproduce copyright material. If any have been inadvertently overlooked, the publisher will be pleased to make the necessary arrangements at the first opportunity. Inquiries for bulk sales may be solicited at: [email protected] Technical Variations and Refinements in Head and Neck Surgery First Edition: 2014 ISBN 978-93-5152-317-8 Printed at:

Dedicated to Jack and Kaia and all the aspiring Head and Neck Surgeons around the globe

Preface

“A large part of abdominal work is recreation as compared with the work of what might be called the heavy surgery of the neck”. Charles H Mayo, 1905 Unique among the specialties that make up the field of cancer care, surgical oncology is both a science and an art. The outcome of patients with head and neck cancer depends not only on the surgeon’s decision-making and knowledge base, but also on his technical ability to accomplish a surgically safe and complete cancer operation. No two operations are the same, no surgery is ever routine, and even “minor” technical aspects of the procedure can affect the patient’s quality, and length of life. This is a perennial aspect of high-quality cancer care that is difficult to convey in a textbook or journal article. Over the past 30 years, training programs for the increasingly complex specialty of Head and Neck Surgical Oncology have evolved to train the next generation in high quality surgical care for diseases of the head and neck. This textbook will cover the advanced technical aspects, variations, and refinements of head and neck surgical procedures, developed by the senior author over the past 40 years. These variations in technique are currently practiced by the surgeons on the Head and Neck Service at Memorial Sloan-Kettering Cancer Center in New York, USA. For each procedure, the refinements will be directly compared with conventional surgical techniques. These refinements were developed, keeping function and esthetics in mind, which clearly impact on the quality of life. This focused text is a companion to Jatin P Shah’s Head and Neck Surgery and Oncology, 4th edition, and therefore does not seek to cover oncologic aspects of surgical decisionmaking, nor does it encompass the critical multi-disciplinary nature of head and neck cancer treatment, or the rapidly evolving science of the field. It also does not describe the step by step conduct of operations, for which the reader is referred to the main textbook. On the other hand it highlights the important components of operative procedures, concentrating on technical nuances. Thus, this book is intended to take the reader on a focused tour through some major refinements to the performance of the craft of head and neck surgery. We hope that this work will be of value to residents and fellows in training, as well as established surgeons who may not perform a high volume of head and neck procedures. Luc GT Morris Jatin P Shah

Acknowledgments

We would like to thank the many courageous patients with head and neck cancer who we have had the good fortune to meet, treat and glean inspiration from. We would also like to thank Ms Raia Mohammed and Mr Benjamin Hegel of the Head and Neck Service for their superb editorial assistance, Ms Chetna Malhotra Vohra (Senior Manager—Business Development) and Ms Sheetal Arora (Development Editor) of M/s Jaypee Brothers Medical Publishers (P) Ltd., New Delhi, India.

Contents

1.

Basic Surgical Principles

1

 Operating Room Setup and Instrumentation  1  Basic Surgical Techniques  8

2.

Surgery of the Scalp and the Skin of the Face and Neck 14  General Principles  14  Surgery of the Scalp  15

3.

Nose, Paranasal Sinuses, and Orbit

26

 Facial Incision  26  Partial Maxillectomy  29

4.

Skull Base Surgery

35

 Anterior Craniofacial Surgery  35  Endonasal Skull Base Surgery  36  Middle Cranial Fossa and Infratemporal Fossa  37

5.

Oral Cavity

42

 “V” Excision of the Lip  42  Partial Glossectomy  42  Skin Grafts in the Oral Cavity  45  Management of the Mandible: Segmental Mandibulectomy  46  Management of the Mandible: Marginal Mandibulectomy  48  Mandibulotomy  52  Optimizing the Lip-splitting Incision  55  Palatal Fenestration for Hard Palate Tumors  57  Repair of the Central Palatal Defect  58

6.

Larynx, Hypopharynx and Trachea  Low-stage Tumors  59  Advanced Laryngeal Tumors  60  Total Laryngectomy or Pharyngolaryngectomy  61  Pharyngeal Closure  64  Tracheoesophageal Puncture  65  Tracheal Resection  66

59

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Technical Variations and Refinements in Head and Neck Surgery

7.

The Neck

69

 Lymph Node Biopsy  69  Neck Dissection  70  Extent of Neck Dissection  71  Preservation of the Marginal Mandibular Branch of the Facial Nerve  72  Preservation of Skin Sensation  74  Preservation of Vascularity of the Accessory Nerve  74  Selective Neck Dissection in the Postchemoradiation Salvage Setting  75  Central-compartment Node Dissection  76  Placement of Suction Drains  77

8.

Thyroid and Parathyroid Glands

78

 Thyroid Lobectomy or Total Thyroidectomy  78  Thyroidectomy and Neck Dissection  81  Surgery for Large Thyroid Tumors and Retrosternal Goiters  81  Nerve Monitoring  83  Parathyroid Surgery  84  Minimally Invasive Parathyroidectomy  84  Four-gland Exploration and Subtotal Parathyroidectomy  86

9.

Salivary Glands

88

 Superficial Parotidectomy  88  Parotidectomy and Excision of Deep Lobe Parotid Tumor  94  Excision of the Submandibular Gland for Sialolithiasis  97

10. Other Tumors

99

 Carotid Body Tumors and Paragangliomas   99

11. Transoral Surgery and Endoscopic Techniques

103

 Transoral Laser Microsurgery and Transoral Robotic Surgery  103  Endoscopic Management of Tracheal and Subglottic Stenosis 115  Percutaneous Endoscopic Gastrostomy Tube Insertion  118

Index 123

Chapter

Basic Surgical Principles

1

OPERATING ROOM SETUP AND INSTRUMENTATION Operating Room Setup Head and neck surgery developed during the first half of the 20th century as a surgical discipline focused on the management of diseases and neoplasms arising in the head and neck. This specialty initially encompassed the fields of general surgery, otolaryngology, plastic and reconstructive surgery, and other allied specialties, such as thoracic surgery and neurosurgery. The primary focus of the specialty has always been the surgical management of head and neck cancer. As the understanding of the biology of these tumors has evolved during the last 60 years, traditional, established operations are being revised or modified as we seek to maintain oncologic efficacy while reducing the physical and functional impact on the patient. At the same time, technological developments have greatly improved the safety and the ease of conduct of operative procedures in the head and neck, such that major efforts at resection and reconstruction are now safe and routine. The physical characteristics of the operating room (OR) have evolved during the last 50 years. Initially a simple room with an overhead light and basic surgical instruments, the OR has become a highly advanced, technologically state-of-the-art environment with equipment for electrosurgical, laser, endoscopic and robotic instrumentation, as well as instrumentation for real-time image guidance and intraoperative video monitoring and recording. The modern-day OR is larger than its predecessor, to accommodate the increased needs for personnel and equipment during operative procedures. Space becomes especially critical in head and neck operations involving multiple surgical teams, for example, when microvascular reconstructive, intracranial, or intrathoracic approaches are used. The OR is equipped with laminar airflow and is separated by a green core and a gray core. The floor space available in the OR should allow easy flow of OR personnel and convenient placement of electrosurgical equipment and towers, video monitoring towers, and robotic equipment, as well as laser surgical equipment including an operating microscope. To minimize clutter

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 1.1: Depiction of a contemporary operating room.

from electrical wires, tubes and connections, all electrical connections, wires, and ducts for the delivery of gases and suction channels should emanate from ceiling-mounted cylinders. Ideally, mobile flat-screen TV monitors for open procedures and endoscopic procedures should be mounted to the ceiling. A modern-day OR that is equipped with these capabilities is shown in Figure 1.1. To most effectively maintain the routine for the day-to-day conduct of common operative procedures, the position of equipment in the OR should remain constant. Whenever possible, the position of the operating table and equipment should be standardized so that they remain in the same location for various procedures. The head of the operating table should generally remain in proximity to the anesthetic equipment. Turning the operating table should be avoided unless specific circumstances absolutely require different positioning. Most head and neck surgical procedures are conducted with a single surgical team consisting of the operating surgeon and two assistants. A scrub nurse and a circulating nurse are essential members of the surgical team. Similarly, an anesthesiologist with at least one assistant is required for induction and smooth conduct of anesthesia throughout a long operative procedure. A nursing assistant must be available on demand at all times. Several complex surgical procedures require the involvement of more than one surgical team. These two-team procedures may be conducted sequentially, or both teams may require simultaneous intervention. Therefore, when multiple surgical teams are involved, the plan of the conduct of the surgical procedure and the sequence of involvement of each surgical team should be discussed in advance with the OR nurses and the anesthesiologist to ensure smooth conduct

Basic Surgical Principles

of the procedure. Presence of visitors, students and others observing the surgical procedure is generally a routine for ORs in most academic institutions. However, to minimize overcrowding in the OR, a video camera mounted on the operating light, with large monitors, should be available to allow observers to watch the operative procedure without being too close to the surgical team.

Setup for Specific Surgical Procedures Standardization of placement of instrument tables and trolleys is critically important for making complex head and neck procedures routine. To avoid unnecessary delays and to eliminate confusion about the location of equipment during the operative procedure, the positions of surgical team members should be relatively constant. Since most operations on the upper aerodigestive tract and paranasal sinuses are considered clean-contaminated procedures, perioperative antibiotic coverage is frequently required before the incision is made. The patient is brought into the OR with a satisfactory intravenous line, and the first dose of antibiotics is given before induction of general anesthesia. General anesthesia is then induced. The placement of the anesthetic endotracheal tube and its connections and the positions of the surgical team, for general open head and neck operations, are shown in Figure 1.2. For a surgical procedure on the right hand side of the patient,

Fig. 1.2: Position of the surgical team for standard open head and neck operations. The primary surgeon (blue) customarily stands on the patient’s right, with the assistants (orange) at the head of the bed and standing opposite. The anesthesia circuit is sterilely isolated at the top of the bed and brought out toward the anesthesiology team (purple). The scrub nurse (light blue) is positioned along the patient’s side.

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 1.3: Sterile drape for head and neck surgery, comprised of two sterile drapes, placed under the head. One drape is placed flat on the bed and tucked under the shoulder blades; the other is wrapped around the head and used to secure the anesthesia tubing.

the operating surgeon stands on the right hand side of the patient, with the first assistant situated at the head end of the operating table and the second assistant directly across from the operating surgeon, on the left hand side of the patient. The endotracheal tube and anesthetic connections are isolated by sterile transparent drapes brought out at the top of the bed, between the first and second assistants (Fig. 1.3). Intravenous access to the patient, through a line in the upper extremity, is provided through the contralateral arm, which may be kept abducted at 90° and isolated out of the sterile field, or it may be tucked next to the patient with an extension of the intravenous tubing. The anesthesiologist should have access to the endotracheal tube and oral cavity, as well as to the intravenous line; therefore, an appropriate length of anesthetic tubing and intravenous line should be made available. The scrub nurse may stand on the right or left hand side of the patient, with the Gerhardt instrument table brought over the patient on the operating table, up to the level of the umbilicus. The electrosurgical unit is positioned behind and between the operating surgeon and the scrub nurse. Suction tubing and collection chambers are positioned farther out from the operating team and are connected to the ceiling-mounted suction channels. Waste-disposal buckets are necessary and should be positioned adjacent to the operating surgeon and the first assistant. Further illustrative diagrams for a variety of operative procedures are shown in Figures 1.4A to C.

Basic Surgical Principles

A

B Figs 1.4A to C: (A) Position of the surgical

C

team for transoral laser microsurgery. The primary surgeon (blue) sits at the patient’s head with the microscope. Connections to the laser and smoke evacuator are brought down toward the patient’s feet. The scrub nurse (light blue) and assistant stand to the surgeon’s side. The anesthesiologist (purple) is positioned toward the patient’s other side, or alternatively, at the patient’s feet; (B) Position of the surgical team for craniofacial surgery. The neurosurgeon and head and neck surgeon (both in blue) stand at the top of the head, and the patient’s side, respectively, with their assistants (orange). Scrub nurses for each team (light blue) are positioned accordingly; (C) Position of the surgical team for head and neck operations with free flap reconstruction, depicting the positions of each team’s scrub nurse (light blue).

Basic Surgical Instrumentation In addition to the fundamental basic instrumentation for an open surgical procedure, the modern-day operating suite is equipped with a variety of new technical devices. This new equipment aids the surgeon in completing the operative procedure safely, often expeditiously, and with better visualization and reduced blood loss.

5

6

Technical Variations and Refinements in Head and Neck Surgery

Fig. 1.5: Standard tips for electrosurgical instruments. From left to right, insulated needle tip and flat tip (generally used in the oral cavity); extended length insulated flat tip (generally used in the oropharynx); Colorado tip (generally used for fine dissection in the skin or mucosa); standard needle tip (for incision through dermis); standard flat tip.

Electrodissection Instruments The standard needle tip is recommended for making the incision in mucosa or skin. It minimizes charring and gives a clean and sharp cut without bleeding. After incision of the epidermis with the scalpel, we recommend using the needle tip to incise the dermis on a pure cutting current. This allows exposure of the subcutaneous fat plane, with minimal bleeding and charring of the cut edges of the skin. In contrast, cutting deeper with the scalpel blade will invariably lead to dermal and subcutaneous bleeders, which obscure the field and, if cauterized, lead to burning of the skin. Once the dermis is incised, the paddle tip is used generally throughout dissection of nearly all operative procedures; it is indeed the workhorse for the surgeon. It is necessary to remember that dissection should be performed in the direction of the tip, using it as a blade and not as a brush. To avoid inadvertent burning of the lips during intraoral surgery, we recommend the use of an insulated needle and paddle tips for the cautery unit (Fig. 1.5). The Colorado tip is an extra fine needle tip that is coated with Teflon to prevent accumulation of charred tissue on the needle. The usual needle and paddle tips are too large for working in delicate regions that include fine, thin tissue, such as the skin of the eyelids.

Basic Surgical Principles

Fig. 1.6: “Shah” Angled bipolar cautery forceps.

Straight bipolar forceps: In general use, bipolar forceps provide excellent hemostasis without excessive charring of tissue. These also offer the advantage of safe use in patients with pacemakers. One disadvantage of the straight bipolar forceps is that they provide pinpoint coagulation of an exposed vessel but are less effective in controlling oozing or bleeding along a flat surface. “Shah” bipolar forceps: These bipolar forceps are devised with fine tips angled at 30–45°, which allows linear coagulation along a flat surface. They are effective in controlling surface oozing from muscle, thyroid gland and vascular tumors, such as carotid body tumors and paragangliomas (Fig. 1.6). Their use facilitates a larger area of surface coagulation, without deep tissue charring. Electrocautery tip extensions: Extensions of up to 10 cm are available for both the needle tip and the paddle tip, to allow working in deep regions, such as the oropharynx and the pharyngeal wall, through the open mouth. Other more recently developed instruments offer additional salutary advantages, although at somewhat increased cost. Ligasure cautery device (manufactured by Covidien): This is a bipolar cautery device with impedance measurement by a computer, which allows modulation of energy delivery until the tissue is coagulated. It combines electrocautery with physical pressure when the handpiece is clamped onto tissue, flattening and coagulating vessels. This technology coagulates vessels up to 7 mm in size, although the handpiece is slightly larger than bipolar forceps and can sometimes be cumbersome in small areas. Nevertheless, it can be safely used, with minimal dissipation of heat, near nerves. Examples of vessels appropriate for this device are the feeding vessels of the thyroid gland.

7

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Technical Variations and Refinements in Head and Neck Surgery

Harmonic scalpel (manufactured by Ethicon): Rather than using electrical current, the harmonic scalpel vibrates at 55,500 Hz, causing protein denaturation and coagulating vessels up to 5 mm in size. This allows the device to simultaneously cut and coagulate tissue, with minimal spread of heat and no electricity, making it safe near nerves. A disadvantage is that the device cannot be used for coagulation alone, as it cuts all tissue placed between the blades. In addition, the handpiece can be too large to use in narrow fields. Handheld carbon dioxide laser scalpel (manufactured by Omniguide): This device uses a flexible fiber to conduct CO2 laser energy to a straight or curved handpiece, which offers the advantage of maneuverability; it can be used for open surgery or transoral surgery or placed through a laryngoscope. The mode of action of this device is easily modulated by distance from the tissue: if held 2–3 mm away, the laser cuts finely; if held 2–3 cm away, the laser beam becomes diffuse and instead coagulates tissue. However, bleeding vessels that cannot be controlled with “spot-welding” will still require coagulation by traditional means. This device is well-suited for transoral approaches to the supraglottic larynx and oropharynx.

BASIC SURGICAL TECHNIQUES Skin Incision and Elevation of Skin Flaps It is generally recommended that the planned skin incision be marked out on the patient before beginning the surgery. The fundamental principle of surgery of the head and neck is to place incisions along natural skin lines. A general understanding of Langer’s lines is required to appreciate the esthetic outcome from a healed incision (Figs 1.7A and B). If local skin flaps are to be used to reconstruct small surgical defects, they should be planned in such a way that both the donor site defect and the reconstructed site are esthetically pleasing, keeping in mind the relaxed skin tension lines and the esthetic subunits of the face. The skin incision is made with a sharp scalpel blade. The skin incision should not be made deeper than through the epidermis layer (Fig. 1.8). If the skin incision is carried through to subcutaneous fat, dermal vessels will create nuisance bleeding, obscuring the field and tempting the surgeon to use cautery on the skin. Instead, the dermis should be incised with the needle-tip Bovie on a cutting current (not using coagulating current, which will create thermal injury to the skin edges). This creates a fine incision to subcutaneous fat, preserving the skin edges and maintaining hemostasis (Fig. 1.9). The remainder of dissection in open head and neck surgery is largely performed with electrocautery, using the flat paddle tip (Fig. 1.10). This allows expeditious elevation of skin-platysmal flaps. Dissection with electrocautery is a satisfying technique, producing a clean, sharp, bloodless operative field

Basic Surgical Principles

A

B

Figs 1.7A and B: Relaxed skin tension lines guide the design of skin incisions.

Fig. 1.8: In open head and neck surgery, incision through the epidermis only is carried out with a sharp scalpel blade.

and resulting in expeditious execution of the operative procedure. However, there are several critical concerns necessary to achieve the maximum benefit of electrocautery dissection. The tissues being dissected must be dry and under constant tension. Electrocautery dissection will not be effective in a

9

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 1.9: The needle tip Bovie is then used to incise the dermis only.

Fig. 1.10: The flat tip Bovie is then used to incise the platysma.

wet surgical field (caused by blood, tissue fluid or irrigation). Similarly, tissues that are lax and not under sufficient tension or traction will not be amenable to good dissection with electrocautery. Accordingly, the plane of dissection must always be maintained in tension by retraction and countertraction,

Basic Surgical Principles

Fig. 1.11: Skin flaps are raised with the flat tip Bovie using a light touch and emphasizing tissue traction and countertraction.

and dissection relies on a light touch, without digging the blade into tissue (Fig. 1.11). Pinpoint bleeding during dissection is most effectively controlled by the use of hemostats or fine forceps, coagulation by monopolar cautery, and diffuse surface bleeding by bipolar cautery; larger vessels need to be ligated. To avoid collateral injury from spread of current from monopolar cautery, bipolar cautery is strongly recommended to control bleeding in the vicinity of nerves and major vessels.

Access, Exposure, Visualization and Stability Access and exposure are crucial in any surgical procedure. Fortunately, for performance of the required surgical procedure, most parts of the neck and face are readily exposed after elevation of the skin flaps. While an assistant can help retract the skin flaps and provide the requisite exposure, elastic rubber blunt fish hook retractors are also an excellent addition to the surgeon’s armamentarium. We recommend generous use of these relatively cheap and simple tools, which retract skin flaps in the desired direction without injuring tissue (Fig. 1.12). The overhead OR light is often inadequate to provide sufficient lighting for intraoral procedures, owing to a narrow field and the inevitability of surgeons’ heads blocking the light. To provide sufficient lighting for intraoral operations, we strongly recommend the use of headlights worn by both the surgeon and the first assistant.

11

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 1.12: Fish hooks (inset), provide excellent retraction of skin flaps.

Stability of the surgeon’s arms is crucial during endoscopic laser resections, which can take from several minutes to several hours. A comfortable chair with adjustable armrests is indispensable for supporting the operating surgeon’s arms, providing stability and avoiding tremor (Fig. 1.13).

Basic Dissection Technique Since most open head and neck surgery relies heavily on electrocautery, special precautions and dissection techniques must be followed to maintain absolute hemostasis and to avoid burning or charring tissue or causing thermal damage to adjacent structures. As mentioned above, dissection with electrocautery works best with the tissues under tension, using traction and countertraction techniques. We recommend that the electrocautery current setting be adjusted by each surgeon for his or her level of comfort, with cutting current on “pure” or a low blend setting and coagulating current on “low” or “desiccate,” avoiding the “spray” and “fulgurate” modes. These settings should be calibrated to the surgeon’s individual preferences. Judicious use of the bipolar forceps near nerves, at low settings ranging from 5–10 watts, can achieve excellent hemostasis of small vessels, without collateral damage to nearby tissues. When the plane of dissection in the head and neck is contiguous with underlying vital structures, such as nerves and vessels, the usual dissection technique of “cut and see as you go” is not advisable. Tissue dissection in these regions can be performed with a fine-tip long hemostat, such as

Basic Surgical Principles

Fig. 1.13: An example of the surgical chair used for transoral laser microsurgery, with adjustable armrests.

Fig. 1.14: Commonly used dissection clamps: a fine Adson hemostat (top) and a micro-mosquito hemostat (bottom).

an Adson hemostat clamp, or a fine tonsil clamp. In some regions, use of a finer dissecting clamp, such as a fine mosquito clamp, can be advantageous (Fig. 1.14). The tissues to be dissected are first entered with the fine tip of the clamp, separated and elevated from the underlying tissues to be protected, and then divided by the use of electrocautery. This sequence of actions results in safe, bloodless, and expeditious dissection.

13

Chapter Surgery of the Scalp and the Skin of the Face and Neck

2

GENERAL PRINCIPLES To appreciate the complexities involved in surgical procedures on the scalp and skin of the face and neck, four basic areas need to be understood: 1. Arterial blood supply of the skin and scalp 2. Venous drainage of the skin and scalp 3. Anatomy of the underlying muscles of facial expression 4. Relaxed skin tension lines (Figs 2.1 and 2.2). Nearly all of the blood supply to the scalp and face is provided by the branches of the external carotid arteries, through the facial, superficial temporal and occipital arteries. The skin of the neck also derives blood supply from the internal mammary, transverse cervical, and suprascapular

Fig. 2.1: Depiction of the major blood supply to subsites and angiosomes of the face. (1) Infraorbital and inferior alveolar; (2) Labial branches of the facial artery; (3) Supratrochlear and supraorbital arteries; (4) Superficial temporal artery distribution; (5) Auricular branches; (6) Occipital artery; (7, 8) Transverse cervical and supraclavicular arteries; (9) Inferior thyroid artery; (10) Superior thyroid and lingual artery branches.

Surgery of the Scalp and the Skin of the Face and Neck

Fig. 2.2: Relaxed skin tension lines guide the design of skin incisions.

arteries. Accordingly, planning incisions for resection and elevation of local or regional skin flaps for reconstruction should include particular attention to the vascular anatomy of the skin. For esthetic reasons, all incisions should be planned along natural skin creases and relaxed skin tension lines, which generally run perpendicular to the direction of underlying facial muscles.

Infiltration before Incision To minimize bleeding, many surgeons use infiltration of local anesthetic with epinephrine in the subcutaneous plane before incision. We do not feel that this is an effective adjunct and do not routinely use it. Frequently, waterlogged tissues hamper the use of electrocautery, as do injection hematomas. If scalpel incision is limited to the epidermis and electrocautery is used for the dermis, the skin incision is bloodless and further vasoconstriction is not needed.

SURGERY OF THE SCALP Scalp Incisions The scalp is a highly vascular region of the head and neck, and simple skin incisions on the scalp, such as a coronal incision for a bifrontal craniotomy, can result in significant blood loss.

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 2.3: Depiction of a scalp excision with incisions oriented at 90° (not recommended).

When feasible, surgical procedures on the scalp should be performed with the patient in a sitting position. This will minimize bleeding from the scalp, taking advantage of reduced arterial pressure and venous backflow. In addition, we discourage the use of the scalpel for incising the scalp. We recommend that an electrocautery device should be used, with a blend of cutting and coagulating functions, to minimize bleeding from small vessels and to allow the surgeon to identify the major feeding vessels and either ligate them or coagulate them. This technique permits essentially bloodless surgery on the scalp in an expeditious manner. Use of electrocautery rather than the scalpel for incision through the galea will often obviate the need for the application of Raney clips.

Primary Closure versus Skin Graft versus Rotation Flap The nature of the incision through the thickness of the scalp depends on the planned method of closure of the surgical defect. If a primary closure or a rotation scalp flap or other flap closure is planned, the incision through the thickness of the scalp should be at 90° to the surface of the scalp (Fig. 2.3). On the other hand, if a skin graft is planned for resurfacing of the scalp defect, a 90° cut through the thickness of the scalp should be avoided. Such an incision creates a troughlike effect, allowing crusting and dry sebaceous material to collect at the periphery of the graft (Fig. 2.4). Therefore, when a skin graft is planned, the incision on the scalp is beveled at an angle closer to 45°. This allows the skin graft to fuse with the raw surface of the cut edge of the scalp smoothly, without leaving a troughlike defect and resulting in an esthetically superior result (Fig. 2.5).

Surgery of the Scalp and the Skin of the Face and Neck

Fig. 2.4: Incisions oriented at 90° create troughlike defects in the scalp, which predispose toward accumulation of crusting and dry sebaceous material.

Fig. 2.5: Depiction of scalp excision with beveled incisions (recommended).

If a split-thickness skin graft is used for coverage of the surgical defect on the scalp, it should be as thick as possible, and not meshed. Thin splitthickness skin grafts will always be susceptible to being easily traumatized and ulcerated. Esthetically, they are conspicuous, resulting in a shiny “skinon-bone” appearance (Fig. 2.6).

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 2.6: The shiny “skin-on-bone” appearance that results from using split-thickness skin grafts on the scalp.

Fig. 2.7: Scalp excision, with preservation of pericranium, except for a central portion where pericranium has been removed. This central portion of exposed bone will not support a skin graft.

A skin graft will not be supported in cases in which some or all of the pericranium has been resected as a deep margin (Fig. 2.7). In such cases, bare cortical bone will not support a skin graft, which relies on imbibition

Surgery of the Scalp and the Skin of the Face and Neck

Fig. 2.8: Design of a double rotation scalp flap to reconstruct a wide scalp defect. In this case, a rotation flap was preferred to a skin graft, as postoperative radiation therapy was anticipated.

Fig. 2.9: Appearance of the scalp after wide excision and rotation of flaps.

and inosculation from underlying tissue. However, the cortical bone can be drilled down to bleeding cancellous bone, which will form granulation tissue, ultimately supporting a skin graft. We prefer to perform a scalp rotation flap in these cases. Scalp rotation flaps, elevated above the level of the pericranium, carry a robust blood supply and provide immediate closure of the donor site (Figs 2.8 and 2.9). In cases where postoperative radiation therapy is

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 2.10: Appearance of the scalp rotation flap immediately after postoperative radiotherapy.

Fig. 2.11: Galeal relaxing incisions are not recommended. They contribute minimal stretch to the inelastic scalp but compromise blood supply to the rotation flap.

anticipated, a rotation flap will withstand irradiation better than a skin graft (Fig. 2.10). Nevertheless, because the scalp lacks laxity, closure will generally be under some tension. Therefore, scalp rotation flaps should be designed with a broad front. In most cases, we do not recommend galeal relaxing incisions (galeotomies); these provide minimal stretch but place the blood supply of the flap at significant risk (Fig. 2.11). When a scalp flap closure is under extreme tension, it is preferable to place a small skin graft at the donor

Surgery of the Scalp and the Skin of the Face and Neck

site (where periosteum has been preserved and will support a skin graft), rather than risk loss of the tip of the rotated flap. Once inset, the distal tip of the scalp rotation flap is generally placed under some tension and may undergo epidermolysis, although the galeal closure will generally remain viable. It is important to be aware of this potential sequela in the postoperative period and to implement wound care and even conservative debridement as needed, to promote healing.

Method of Fixation of Skin Graft on the Scalp Traditionally, the skin graft applied to a defect on the scalp is sutured with silk sutures, several of which are left with long ends to be used for tying over a bolster, to retain the graft in position. When these sutures are tied down over the bolster, the cut edges of the scalp defect along the periphery are lifted off the pericranium, which can cause a subgaleal hematoma (Fig. 2.12). We therefore feel that this method of fixation of the skin graft on the scalp is not satisfactory. We recommend the following: • Excision of the scalp lesion with a beveled scalp edge • Suturing the skin graft to the scalp edges with a running suture of 3-0 catgut. This offers complete hemostasis from the cut edge of the scalp, and the sutures do not have to be removed. • A series of skin staples applied circumferentially around the periphery of the scalp defect, approximately 1 cm from the edge of the defect • Silk ties passed through the stapled area and left long to be tied over the bolster

Fig. 2.12: Scalp edges lifted off the bone by tie-down sutures (not recommended). Skin graft depicted in blue. Bolster depicted in yellow.

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 2.13: The bolster is secured to staples at least 1 cm from the wound edge, avoiding lifting of the edges of the scalp defect (recommended). Skin graft depicted in blue. Bolster depicted in yellow.

Fig. 2.14: Long-term result of the described refinements, including beveled incisions, thicker skin graft and tie-down sutures.

•

The silk ties are tied over the bolster, without lifting the edges of the scalp defect (Fig. 2.13). Sutures at the periphery of the defect help to ensure complete take of the skin graft. Removal of the bolster is easy and painless for the patient, since the staples need only be removed and no sutures are removed from the skin graft. The potential for subgaleal hematoma is avoided. The long-term result of this technique is very pleasing (Fig. 2.14).

Surgery of the Scalp and the Skin of the Face and Neck

Wedge Excision and Primary Closure of the Pinna Small skin cancers on the helix of the ear often require a wedge excision, and the defect is closed primarily. One of the complications of this technique is that the suture line often separates, causing dehiscence. This occurs because of retraction of the skin over the cartilage. To avoid this, the following steps should be taken: • After adequate wedge excision, hemostasis is secured by pinpoint electrocoagulation of small subcutaneous bleeders • At this point, one notices that the skin edges of the defect have retracted away from the cut ends of the cartilage, both anterior and posterior to the cartilage, and cannot be pulled back together • Therefore, approximately 1–1.5 mm of the edge of the protruding cartilage needs to be trimmed (Figs 2.15A and B) • This procedure permits easy closure of the anterior and posterior skin in two layers, without tension. Large wedge excisions of the auricle will create the appearance of a proptotic ear as it is distracted forward by the sutures. In these cases, a conchal bowl setback suture should be used, exactly as in otoplasty for prominent ears. Through a postauricular incision, mattress sutures of fine permanent suture are placed through auricular cartilage and mastoid periosteum and tied, bringing the auricle back.

Excision and Primary Closure of Facial Skin Lesions Excision of small skin lesions on the face should be performed in an elliptical fashion along facial relaxed skin tension lines. If primary closure of the surgical defect can be achieved without tension, then that is the best way to repair such surgical defects. This technique is esthetically very pleasing. If, however, the surgical defect is large and is unable to be closed primarily, other means of repair of the defect will be required. These include: • Skin graft, either full thickness or split thickness • Local flaps • Regional flaps • Free flaps Skin grafts are generally used on the parts of the face where there is no movement or facial expression, such as the dorsum of the middle third of the nose, the temple, the preauricular region, and the forehead. When feasible, a full-thickness skin graft is preferred, keeping in mind the size limitations for the harvest of a full-thickness skin graft. In general, a full-thickness skin graft of up to 4 × 4 cm, harvested from the neck, is quite satisfactory from the point of view of color match, as well as for the possibility of primary closure of the donor site.

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Technical Variations and Refinements in Head and Neck Surgery

A

B Figs 2.15A and B: Closure after wedge excision of the auricle. Protruding cartilage is excised to facilitate closure.

Smaller grafts with excellent color match can be harvested from the preauricular region, closing the defect in line with a preauricular skin crease. If the neck is not available as a donor site, large grafts from lax skin in the deltopectoral groove or on the abdominal wall can also be primarily closed, although they offer poorer color match for the face. On all other parts of the face, local flaps should be used for small defects; when local flaps are not large enough to fill the defect, regional or free flaps should be used. Facial skin lines and facial expression are crucial factors in designing a local flap to repair a surgical defect. The goal should be to leave minimal esthetic or functional deficit.

Surgery of the Scalp and the Skin of the Face and Neck

The planning and design of local flaps for repair of facial defects require knowledge of superficial vascular anatomy of the head and neck, as well as an appreciation of the esthetic and functional units of the face. Owing to the extensively rich blood supply of facial skin, any flap with a length to width ratio of 3:1 can be safely used. In such a setting, esthetic planning of the donor site closure will play a major role. Axial flaps with a larger length-to-width ratio require an identifiable feeding vessel. The reader is referred to larger publications on various types of facial skin flaps, which are beyond the scope of this publication.

25

Chapter Nose, Paranasal Sinuses, and Orbit

3

INTRODUCTION Several technical modifications, refinements and reconstructive efforts can improve exposure for adequate resection of tumors while decreasing the esthetic and functional morbidity of open surgical procedures.

FACIAL INCISION One of the significant problems in surgical management of neoplasms of the nasal cavity and paranasal sinuses that are not amenable to endoscopic resection is surgical access. Although the Weber-Ferguson incision, with its various extensions (Diffenbach, subciliary, transconjunctival and Lynch), has provided excellent exposure for the last several decades, the esthetic and functional sequelae of this approach leave much to be desired. The standard Weber-Ferguson incision with standard extensions, as originally described, has the following disadvantages: • Unacceptable scar • Does not respect nasal subunits • Causes flaring of the ala • Distorts the nasal aperture • Causes cicatricial ectropion of the lower eyelid • Widens the palpebral fissure • Causes loss of nasolabial symmetry. To avoid these esthetic and functional sequelae, a significant modification of the incision has been developed and practiced by the authors for more than 15 years. The short- and long-term outcomes of this modification have stood the test of time. The incision provides essentially the same exposure but is placed in skin creases of the nasolabial-orbital region, respecting the nasal subunits, and the periorbital skin crease. The incision is not a subciliary incision and is placed away from the tarsal margin, thereby minimizing cicatricial ectropion. The incision is shown in Figures 3.1 and 3.2.

Nose, Paranasal Sinuses, and Orbit

Fig. 3.1: Modifications to the lateral rhinotomy incision include a notch in the nasal sill following the columella in the floor of the nasal cavity and careful respect of the alar border and the nasal subunits. Importantly, the incision is not placed in the nasolabial fold.

Fig. 3.2: Modifications to the Weber-Ferguson incision include careful respect of nasal

subunits, and avoidance of a subciliary incision, which causes ectropion. Instead, the skin incision is brought down lower, in an infraorbital skin crease.

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Technical Variations and Refinements in Head and Neck Surgery

The incision must be marked on the patient with a marking pen before induction of anesthesia and oral or nasal intubation. Taping of the endotracheal tube pulls the upper lip to one side, causing distortion and displacement of the midline. This can make precise delineation of the midline lip split quite difficult. Even subtle divergence from the midline is easily recognized by the human eye, creating an abnormality that is quite visible postoperatively. The incision begins at the vermilion border of the upper lip, exactly in the midline, splitting the philtrum of the upper lip. The upper lip is divided through its full thickness. To facilitate precise alignment at closure, we find it is helpful to make a small, perpendicular, crosshatch skin incision right at the vermilion border of the lip. The skin incision then follows the mound of the columella into the floor of the nasal cavity. From there, it takes a 45° turn and exits the nasal cavity into the alar groove. It then follows the alar groove, up to the lateral edge of the alar rim. At that point, it takes a nearly 90° turn cephalad, on the side of the nose, medial to the nasolabial skin crease. Note that the incision along the nasal sidewall is not placed in the nasolabial skin crease—doing so invariably flattens the nasolabial fold. The vertical component of the incision extends cephalad up to the medial end of the eyebrow (Lynch extension) or stops at the level of the medial canthus, still remaining on the nose. If a subciliary extension is required, the incision again takes a 90° turn laterally, in the infraorbital region. Here, the incision is kept away from the medial canthus and the tarsal margin. Rather than taking a subciliary course, the incision now follows an infraorbital skin crease. The distance between the skin crease and the tarsal margin varies from patient to patient, but generally the highest infraorbital skin crease is well positioned. The incision can be extended laterally as far as necessary but should remain in the periorbital/orbitozygomatic skin crease. Note that the lateral extension is not placed in the traditional subciliary location on the eyelid, thereby minimizing scar contracture and resultant ectropion. The depth of the skin incision on the upper lip and the nasolabial and paranasal regions is through the full thickness of the soft tissues, down to the bone. However, the skin incision in the infraorbital region is only through the skin, remaining superficial to the underlying orbicularis oculi muscle. By keeping the incision superficial to the muscle, the orbicularis is not disturbed or divided, again minimizing scarring and the risk of subsequent eyelid eversion or ectropion. The skin incision on the upper lip is extended through the mucosa of the upper lip and the upper gingivobuccal sulcus, leaving approximately 8 mm of mucosal cuff on the attached gingiva. The upper cheek flap is then elevated in the usual fashion, directly over the underlying anterior wall of the maxilla but superficial to the orbicularis oculi muscle. Extreme care should be exercised in elevating the skin in this area. The skin is paper thin, and inadvertent “button holes” can occur in the skin if delicate dissection

Nose, Paranasal Sinuses, and Orbit

is not performed. The skin in this area should be elevated superficial to the orbicularis muscle by use of an ultrafine needle tip (Colorado tip) electrocautery device. After the upper cheek flap is elevated completely, as above, and retracted laterally, dissection and elevation of the orbicularis oculi muscle take place. By use of a periosteal elevator, the muscle is gently separated from the underlying maxillary bone up to the orbital rim. Care should be exercised to prevent inadvertent tears in the muscle. The muscle is then retracted cephalad to the lower eyelid, giving complete exposure of the anterior wall of the maxilla. Surgical resection of the tumor is then completed as required by the extent of the tumor. Repair of the surgical defect may require a dental obturator (with or without the use of a skin graft) or a free flap. To achieve an optimal esthetic outcome, closure of the incision requires meticulous attention to detail. The orbicularis oculi muscle is draped back in its normal place. In the infraorbital region, subcutaneous closure is performed with fine 5-0 absorbable sutures (Vicryl). Subcutaneous closure of the remaining incision is performed with 3-0 chromic catgut inverting sutures, carefully matching each of the 90° and 45° angles of the incision. Additional subcutaneous sutures are placed, as necessary, to accurately align all of the nasal and labial subunits. Finally, skin closure is performed with 6-0 interrupted nylon sutures. The typical postoperative appearance, as demonstrated in the same patients before and after surgery, is shown in Figures 3.3 and 3.4. Note the lack of cicatrical ectropion, which is attributable to the modification of the subciliary limb of the incision.

PARTIAL MAXILLECTOMY Extent of Resection Resection of the lower part of the maxilla (infrastructure) involves removal of the anteroinferior portion of the maxilla, below Ohngren’s line. The operation can be easily performed through the open mouth and seldom requires a lateral rhinotomy for exposure. Many textbooks describe this operation as a “hemimaxillectomy,” whereby the entire ipsilateral alveolar process, from the anterior midline up to the junction of the hard and soft palates, is removed. This results in the loss of all of the teeth on that side, which is often not necessary. Depending on the location and extent of the tumor, several uninvolved teeth can be safely preserved. Thus, for posteriorly located tumors of the upper gum or hard palate, the incisor teeth can be safely preserved, retaining the esthetic appearance of the patient and aiding in retention of the eventual dental obturator. Similarly, for anteriorly located lesions, the molar teeth can be preserved.

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Fig. 3.3: Postoperative photo of the patient in Figure 3.1.

Fig. 3.4: Postoperative photo of the patient in Figure 3.2. There is no ectropion.

Preservation of the Soft Palate If the soft palate is not involved and is not required to be resected for oncologic reasons, every effort should be made to preserve any part of the soft

Nose, Paranasal Sinuses, and Orbit

palate (retaining the palatal arch) that can be preserved. This is of tremendous help to the prosthodontist in the fabrication and retention of the dental obturator.

Management of the Postmaxillectomy Defect Traditionally, a split-thickness skin graft is used to line the maxillectomy defect. The advantage is that the defect heals quickly and the immediate postoperative management period is shortened. In addition, the patient is able to start postoperative radiation therapy sooner, if indicated. However, there are several disadvantages to the use of the skin graft. They are that (1) the defect is dry; (2) the epithelialized lining secrets sebaceous secretions, which often produce odor; and (3) the defect requires regular irrigations and a high degree of maintenance. Indeed, the routine use of a skin graft can be avoided in many circumstances. Management of the maxillectomy defect depends on the extent of the surgical defect. The management options can be classified into three categories: (1) infrastructure maxillectomy with pterygoid plates preserved; (2) maxillectomy with resection of the pterygoid plates and the defect extending into the infratemporal fossa; and (3) total maxillectomy with resection of the floor of the orbit. In the case of an infrastructure maxillectomy with intact pterygoid plates, the use of a skin graft should be avoided. Simple packing of the defect with Xeroform gauze intraoperatively and insertion of an immediate dental obturator are sufficient. Oral irrigations during the next several weeks allow the defect to remain clean and epithelialize spontaneously. The long-term outcome with this approach is an excellent, moist, and comfortable defect without any odor or requirement for regular maintenance. If the surgical defect extends into the infratemporal fossa because of resection of the pterygoid plates, there are two choices for repair of the defect: (1) a skin graft and a dental obturator or (2) a skin-lined soft-tissue free flap. If the surgical resection includes a total maxillectomy including the bony support of the orbital floor, a free flap is required to support the rigid reconstruction of the floor of the orbit, whether performed with autologous bone or a metallic plate. The pros and cons of free-flap reconstruction must be weighed before deciding on the management of the maxillectomy defect. The advantages of free-flap reconstruction are: • The defect is immediately closed, requiring no postoperative maintenance • Postoperative radiation therapy can be started in 2–3 weeks • In elderly and edentulous patients with atrophy of the alveolar process, the free flap provides an immediate and permanent solution to the defect • If an osteocutaneous free flap is used, dental rehabilitation with dental implant is possible

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• •

If the orbital floor is resected, the free flap provides support to the globe If orbital exenteration is performed, the free flap provides sufficient soft tissue and skin for immediate reconstruction of the defect There are, however, some disadvantages with free-flap reconstruction. They are: • It requires two surgical teams and prolongs the operation by several hours • In the dentate patient, rehabilitation with a denture is difficult, since, with passage of time, the flap sags and displaces the denture • Prosthetic rehabilitation of orbital defects may be difficult because of an inability to retain the prosthesis in the orbital socket • Placement of dental implants in osteocutaneous flaps is sometimes difficult All of the benefits and disadvantages of a free flap must be weighed, taking into consideration tumor and patient factors.

Palatal Fenestration Central palatal lesions can be removed completely, without the need to sacrifice the uninvolved alveolar process. This is often the case for tumors originating in the minor salivary glands. If the palatal bone is involved, then a full-thickness resection requires creating an oronasal defect, which will require a dental/palatal obturator for speech and swallowing without nasal regurgitation. If, however, the palatal bone is not involved with the tumor and the bone appears normal on imaging studies, then a full-thickness resection can be avoided. Clearly, this is preferable, since it will avoid the need for an obturator. To accomplish the goal of avoiding full-thickness defects, the mucosa of the floor of the nasal cavity must be preserved, without perforating it during resection. At the beginning of the operation, saline with epinephrine (1:100,000) is bilaterally infiltrated into the submucosal plane of the floor of the nasal cavity. A long spinal needle is used, and the submucosal plane of the floor of the nasal cavity is entered through the anterior nostril, advancing along the upper surface of the palatal bone. This hydrodissection creates a plane between the bone and the mucosa of the floor of the nasal cavity. The resection then begins through the open mouth with a circumferential mucosal incision around the tumor. Then, with a power saw or a drill, the bone is scored through nearly 90% of its thickness. Finally, with a small osteotome, the bone is fractured at one place, to allow entry into the previously created plane between the bone and the nasal mucosa. By use of a perio­ steal elevator, the palatal bone is dissected off the undersurface of the nasal mucosa. Finally, by use of the osteotome, the bone is fractured circumferentially, and the specimen is removed. Hemostasis is secured, and a Xeroform gauze packing is placed in the surgical defect. A temporary dental obturator is required to hold the packing in place. The dental obturator is required for several weeks, until the defect granulates in and is covered by palatal mucosa.

Nose, Paranasal Sinuses, and Orbit

Repair of the Central Palatal Defect Small, full-thickness defects in the hard palate can be repaired with a mucoperiosteal or myomucosal palatal island flap from the soft palate; the flap is based on the vascular pedicle from one or both greater palatine arteries (Figs 3.5A to C). This can be performed at the time of resection or secondarily. The ability of such a reconstruction to completely obliterate the oronasal

A

B

C Figs 3.5A to C: Palatal island flap for reconstruction of a hard palate defect.

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Technical Variations and Refinements in Head and Neck Surgery

defect depends on the size and location of the palatal defect. Large and more anteriorly located defects are difficult to repair in this manner and are most effectively managed by use of a dental obturator.

Preservation of the Hard Palate In rare cases, a carcinoma arising from the superior aspect of the maxillary antrum may permit a subtotal maxillectomy, sparing the hard palate. This is very helpful in avoiding the need for palatal reconstruction or the need for an obturator. When contemplating this option, MRI imaging can be helpful in distinguishing between tumor and retained secretions, helping to delineate whether the maxillary sinus floor appears to be free of tumor. In these cases, after raising the cheek flap, a window can be judiciously made in the anterior face of the maxillary sinus. The canine fossa is often the most direct approach. This permits examination of the extent of tumor. If the hard palate can be preserved, bone cuts are made with an osteotome along the medial and posterior walls of the maxilla, and the remainder of the maxillectomy performed in the standard fashion.

Chapter

Skull Base Surgery

4

INTRODUCTION During the last 40 years, the specialty of skull base surgery has matured into a safe surgical undertaking, with operative mortality now in the low single digits and postoperative complications having significantly declined in frequency. These improvements are attributable to increasing experience; technological advances in imaging, surgical navigation, and instrumentation; and moreinformed selection of cases. Clearly, technical improvements have also developed over the years to reduce morbidity, as well as the functional and esthetic impact of craniofacial surgery. The following refinements are noteworthy.

ANTERIOR CRANIOFACIAL SURGERY Traditionally, a bifrontal craniotomy is performed to provide exposure of the floor of the anterior cranial fossa. However, in many instances, such wide exposure is not necessary. Thus, the size of the frontal craniotomy has been steadily reduced over the years, from a wide bifrontal craniotomy, to a smaller bifrontal craniotomy, to a subcranial approach, to a total endoscopic resection without craniotomy. However, reducing the size of the craniotomy or avoiding a craniotomy should not compromise the oncologic completeness of a safe resection. For small central anterior skull base lesions involving only the region of the cribriform plate, a small anterior craniotomy or subcranial approach can be performed. The transfacial exposure may be limited to a lateral rhinotomy or an external ethmoidectomy incision. In some instances with bilateral ethmoid involvement, a nasal bone disassembly approach may be used. In this case, both nasal bones are osteotomized and removed for exposure and then plated back, after en bloc removal of the surgical specimen. There are many approaches to craniofacial resection that obviate the need for facial incisions. For example, small to moderate-sized tumors of the ethmoid sinuses can be extirpated using a cranioendoscopic approach that

36

Technical Variations and Refinements in Head and Neck Surgery

combines bifrontal craniotomy from above with endoscopic-assisted mobilization of the tumor through the nostrils. The surgical specimen can then be removed through the craniotomy exposure. Needless to say, one must have sufficient experience and expertise in nasal endoscopic surgery to accomplish a safe and satisfactory operation.

ENDONASAL SKULL BASE SURGERY With the increasing experience in endonasal surgery for benign inflammatory diseases, there is increasing interest in extending these techniques to resection of malignant tumors. The development of advanced endoscopic instrumentation and real-time imaging/navigation has advanced the ability to use these techniques safely. However, there are several prerequisites that must be met to accomplish a safe endonasal resection of a malignant tumor. These are as follows: • Two surgeons are required: the operating surgeon and an assistant, who handles the camera and other required instruments, such as a suction. In cases of endoscopic intracranial surgery, one of the surgeons is a head and neck surgeon, and one is a neurosurgeon. This is a four-handed technique. • Both surgeons must have sufficient expertise and experience performing endonasal surgery. • Both surgeons should have adequate experience and comfort performing an open craniofacial resection, should an open approach become necessary. • Intraoperative navigation must be available. • Lesions should be small to medium-sized tumors confined to the anterior skull base. • The anatomy of the paranasal sinuses and central skull base must be favorable. The contraindications to the endonasal approach are: • Advanced tumors with extensive bone destruction of the frontal sinus or clivus • Significant tumor extension into the orbit • Significant tumor extension into the middle cranial fossa • Tumor involvement of the lateral wall of the sphenoid sinus • Involvement of the skin • High-grade histology • Insufficient surgeon experience and expertise in endoscopic transnasal surgery Importantly, these approaches use different techniques of tumor dissection. When endoscopic techniques are used, tumors are rarely removed en bloc. Rather, they are first debulked in a piecemeal fashion. If the area of

Skull Base Surgery

skull base invasion is resected en bloc and an appropriate dural resection is performed, if indicated, these techniques can remain oncologically sound. Endoscopic transnasal skull base surgery and reconstruction of the skull base defect has legitimately become a specialty in its own right, the technical aspects of which are beyond the scope of this text.

MIDDLE CRANIAL FOSSA AND INFRATEMPORAL FOSSA Traditionally, lesions of the infratemporal fossa, with or without extension to the middle cranial fossa, have been treated via a maxillectomy approach, with or without middle fossa craniotomy. However, if the anterior wall of the maxilla and the alveolar process of the maxilla are not involved by the tumor, they can be safely preserved, retaining facial contour and the integrity of the palate, by use of the maxillary swing approach. This approach was originally developed for nasopharyngectomy but is quite suitable for lesions of the infratemporal fossa. We find the maxillary swing approach to generally provide superior exposure to the infratemporal fossa, compared with the lateral preauricular approach, which provides entry into the area through a narrow corridor. Providing full technical details of the maxillary swing approach, in a stepby-step fashion, is beyond the scope of this book. However, the broad and important features of the operation are: • The incision is a modified Weber-Ferguson incision, with an infraorbital extension, along a natural skin crease (Fig. 4.1). • The cheek flap is not elevated over the maxilla. In fact, the entire cheek flap must remain attached to the anterior surface of the maxilla to preserve the blood supply to the maxilla. • The skin incision is deepened up to the bone, and only approximately 5–6 mm of soft tissue is elevated from the bone to perform the required osteotomies. • A mucoperiosteal incision is placed on the hard palate, in a paramedian or lateralized position, on the side of the operation, extending from the lateral incisor tooth back to the soft palate, then extended laterally to the maxillary tubercle. To avoid a postoperative palatal fistula, it is critical that the mucoperiosteal incision not directly overlie the palatal osteotomy (Fig. 4.2). • Four osteotomies are performed: (1) in the midline of the hard palate, between the two central incisor teeth, up to the posterior edge of the hard palate; (2) at the nasal process of the maxilla; (3) in the infraorbital region, approximately 3 mm below the anterior orbital rim; and (4) through the zygomatic process of the maxilla, up to the lower border of the zygomatic arch. These osteotomies free up the maxilla for it to swing laterally, except at the posterior margin at the pterygoid plates (Fig. 4.3).

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 4.1: Maxillary swing approach. Modified Weber-Ferguson incision, respecting nasal subunits and using an infraorbital skin crease, rather than a subciliary incision.

Fig. 4.2: Maxillary swing approach. Mucoperiosteal incision, designed to not overlie the palatal osteotomy.

•

A curved osteotome is then used to fracture the posterior border of the maxilla from the pterygoid plates at the hamulus of the pterygoid. Once this is fractured, the assembly of the maxilla and the attached cheek flap

Skull Base Surgery

Fig. 4.3: Maxillary swing approach. With the cheek flap not elevated off of the maxilla,

osteotomies are made through the hard palate, nasal process of maxilla, below the orbital rim, and through the zygoma.

Fig. 4.4: Maxillary swing approach. After performing the osteotomy to separate the posterior maxilla from the pterygoid plates, the maxilla can now be swung laterally.

•

is rotated (swung) laterally by gentle traction, with concomitant sharp division of the attached soft tissues (Fig. 4.4). This maneuver provides wide exposure of the masticator space, infratemporal fossa, undersurface of the greater wing of sphenoid bone, floor

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 4.5: Maxillary swing approach. Realignment of the transposed maxilla with miniplates.

Fig. 4.6: Final appearance after maxillary swing approach. The modified facial incisions

are camouflaged well by respecting nasal subunits and minimize the risk of ectropion. The maxillary swing, rather than maxillectomy, allows maintenance of facial contour and preservation of the palate.

Skull Base Surgery

•



of the middle cranial fossa, and the region of the major foramina of the middle fossa skull base. Thus, this procedure may be used for neurogenic and neurovascular tumors of the infratemporal fossa, soft tissue and bone tumors, minor salivary gland tumors arising from the posterior wall of the maxilla and extending to this region, and other selected situations in which such an exposure would be necessary. Repair of the surgical defect requires simply repositioning the transposed maxilla back into its natural position, followed by plating. Miniplates and screws are used to fix the maxilla in position at the zygomatic arch, at the nasal process of the maxilla, and in the midline at the prema­ xilla. In addition, a prefabricated dental obturator is wired to the upper alveolar process bilaterally. The obturator is retained in position for at least 6–8 weeks. The remaining incision is closed in the usual fashion (Fig. 4.5). The final appearance is shown in Figure 4.6.

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Chapter

Oral Cavity

5

INTRODUCTION There are several fine points to note in surgery for oral cavity lesions that result in superior esthetic and functional outcomes. The details and technical aspects of these refinements are discussed below.

“V” EXCISION OF THE LIP Traditionally, repair of defects of the lip after wedge resection requires accurate alignment of the vermilion border (at the junction of the vermilion or red lip and the external skin of the lip). However, this alone is not sufficient. To optimize the esthetic outcome, there are several other anatomic landmarks that must be aligned accurately. If the lip is viewed in cross section, one can see the protuberance (mound) of the vermilion junction. A fine, everting subcutaneous suture with catgut, exactly at the mucocutaneous junction, restores this prominence (Fig. 5.1). In addition, a subvermilion skin crease is present in the lower lip of nearly all individuals. This must be similarly aligned by use of an everting subcutaneous suture. Similarly, the junction between the dry vermilion (keratinizing mucosa) and the wet vermilion (mucosa containing minor salivary glands) is a line of separation that should also be accurately aligned to achieve the perfect esthetic result. This is the junction between the glistening pink mucosa and pale dry mucosa of the vermilion of the lip.

PARTIAL GLOSSECTOMY Traditionally, many textbooks of surgery recommend a longitudinally oriented resection of lesions on the lateral border of the tongue. Unless the lesion is a long linear lesion (Fig. 5.2), a longitudinally oriented resection will result in too much loss of normal tissue and a long, thin, snakelike tongue, which does not give the optimal functional outcome. Such a long, thin tongue hampers accurate recovery of speech and delays resumption of swallowing.

Oral Cavity

Fig. 5.1: A fine suture is used to evert the mucocutaneous junction at the vermilion border of the lip to create the vermilion “mound”.

Fig. 5.2: A long linear excision of the tongue is appropriate for a longitudinally oriented tongue resection.

For superior functional outcomes, most lesions on the lateral border of the tongue (Fig. 5.3) should be resected using a transverse wedge (Fig. 5.4). A transverse wedge is marked out, with sufficient margins in all dimensions. The apex of the wedge may need to cross the midline. After threedimensional resection of the tumor, and after confirmation of clear margins

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Fig. 5.3: A lateral tongue lesion that is not long and linearly oriented is more common, and better suited for a transverse wedge excision, rather than longitudinal excision.

Fig. 5.4: Design of a transverse wedge excision of a lateral tongue lesion.

of resection by frozen section, repair of the defect should begin. This is performed in two layers. The deep muscular repair is performed with a 2-0 absorbable suture, beginning at the apex of the wedge and working laterally toward its base. A deep muscular suture is placed, bringing the cut ends of the muscles together and bringing the mucosal edges closer. The suture

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should be tied snug, although not too tight, to avoid cutting through musculature. As the closure progresses laterally, one must take into account accurate alignment of the mucosal edges of the dorsum and the undersurface of the tongue. The mucosa of the dorsum of the tongue is rough and “furry,” while the mucosa of the undersurface of the tongue is smooth and glistening. The junction of these two surfaces is exactly at the lateral edge of the tongue. This junction must be accurately aligned. After the muscular closure has approximated the anterior and posterior edges of the cut muscles, mucosal closure is completed with interrupted absorbable sutures. Initially, in the postoperative period, the suture line at the apex of the transverse closure will show a moundlike prominence. This will flatten out during the next several weeks, and a functionally superior outcome will be achieved. By this method, the tongue is foreshortened but retains bulk, thus resulting in superior recovery of speech and swallowing.

SKIN GRAFTS IN THE ORAL CAVITY Repair of mucosal defects in the oral cavity that cannot be repaired by primary closure or that are likely to result in functional impairment of speech and swallowing require consideration of several options. Simple mucosal defects without a significant third dimension can be left open to heal by secondary intention. Examples of these defects are excisions of mucosal lesions such as leukoplakia (hyperkeratosis), in situ carcinoma, or very superficially invasive squamous cell carcinoma located in the floor of the mouth, lateral border of the tongue, buccal mucosa, or hard palate. Larger defects with a third dimension that extend up to the underlying musculature of the floor of the mouth (myelohyoid) or cheek (buccinator) require a skin graft. In general, skin grafts should be avoided on the tongue. Since skin grafts are not sensate, patients often traumatize them by biting during mastication. In contrast, skin grafts may be used in the relatively immobile surfaces in the oral cavity, such as the floor of the mouth, alveolar ridge, buccal mucosa, retromolar region, and hard palate. Whenever a split-thickness skin graft is used in the oral cavity, it should be quite thick (0.025 inch or 0.60 mm). Very thin split-thickness skin grafts in the oral cavity undergo dissolution, appearing to melt away. They slough quickly, and the defect eventually heals by secondary intention. Although 100% take of the skin graft is seldom achieved in the oral cavity, thicker split-thickness grafts are more able to resist the shearing forces of mastication and have a higher probability of surviving in this otherwise hostile environment. Larger three-dimensional defects in the oral cavity—such as those after glossectomy involving more than 40% of the tongue, through-and-through resection of the floor of the mouth, and deep resection of the cheek and retromolar region into the masticator space—all generally require a free flap

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to provide coverage of a larger area of the mucosal defect and soft tissue to fill the three-dimensional defect. The radial forearm free flap works best in these situations.

MANAGEMENT OF THE MANDIBLE: SEGMENTAL MANDIBULECTOMY Lesions in the oral cavity that either involve the mandible or are in proximity to the mandible require consideration of issues regarding management of the mandible. Thus, the mandible may require a mandibulectomy or mandibulotomy. Mandibulectomy is either segmental or marginal. Segmental mandibulectomy is required for primary tumors of the mandible, such as sarcoma or ameloblastoma, and for destruction or invasion of the cancellous part of the mandible from mucosal cancers of the oral cavity. Segmental mandibulectomy may also be required for massive soft tissue disease surrounding the mandible, even if there is no bone destruction. When a segmental mandibulectomy is performed, consideration should be given to immediate mandible reconstruction with a free flap. Confirming histologically clear margins on the mandible by use of intraoperative frozen section is difficult because of the inability to section bone; true evaluation of invasive squamous cell cancer in mandibular bone requires 1 week for decalcification, so that the hard tissue can be sectioned. Therefore, frozen section cannot be relied upon. If possible, a 1 cm margin of bone should be resected. The cancellous bone of the cut edge can then be curetted and smears sent for standard frozen section, with the understanding that this tissue sampling is, by necessity, not perfectly sensitive. If the proximal stump of the inferior alveolar nerve is identifiable, this can also be sent for frozen section, although, again, this technique does not have perfect sensitivity, and if the results are positive only for microscopic (and not for gross) disease, additional resection may not reliably convert the margin to negative. When a segmental mandibulectomy is performed, with immediate reconstruction of the mandible planned, the bone cuts on the mandible are made in such a fashion as to facilitate a mechanically strong and esthetically pleasing reconstruction. To address these issues, several site-specific points need to be followed. The specific sites to be considered are: (1) the condyle and temporomandibular joint; (2) the ascending ramus; (3) the angle; (4) the body; and (5) the symphysis and parasymphyseal region. If resection of the tumor requires excision of the entire ascending ramus of the mandible, the mandible should be disarticulated from the temporomandibular joint. If the condyle of the mandible is uninvolved, it may be excised from the specimen and plated to the bone of the free flap, to recreate a new TM joint. Even though the replanted condyle does undergo some resorption during the next several months, it creates a pseudoarthrosis of the

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temporomandibular joint for better function. On the other hand, if resection of the ascending ramus is performed for intraoral lesions, such as those of the retromolar region or tonsil, then a segmental mandibulectomy is performed in conjunction with marginal resection of the ascending ramus, excising the coronoid process and the anterior half of the ascending ramus of the mandible and preserving the TM joint and the posterior rim of the ascending ramus. This permits reconstruction of the mandible by fixing the free bone flap to the remnant posterior rim of the ascending ramus. Thus, the natural TM joint is preserved, avoiding malocclusion, and the facial contour remains unaltered, owing to the preservation of the lower border of the natural angle of the mandible. Similarly, if the ascending ramus does not need to be sacrificed for tumor resection, a right-angle cut is made through the ascending ramus, preserving the lower border of the angle for esthetic reasons (Fig. 5.5). However, if resection of the mandible is performed through the body of the mandible, then a straight, 90-degree cut is made through the body to facilitate fit with the free flap. For esthetic reasons, similar consideration is given to preservation of the lower border of the mandible in the region of the chin. To facilitate flap insertion while maintaining the contour of the chin, one may consider a stepped osteotomy here. Overall, it is important to realize that the facial contour is retained by preservation of the lower border of the mandible at the angle or in the region of the symphysis. When resection of the tooth-bearing mandible is performed, the bone cuts should be made through the socket of an extracted tooth, rather than between two teeth. In the latter case, the remaining tooth

Fig. 5.5: Design of a segmental mandibulectomy, with osteotomies preserving the angle of the mandible.

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Fig. 5.6: Fixation of a fibula graft to a segmental mandibulectomy defect, where the angle of the mandible has been preserved. In most cases, miniplates can be used rather than high-profile mandibular fracture reconstruction plates.

at the end of the bone, with an exposed root or socket, will eventually be lost and will often cause sepsis at the site of bone union between the free flap and the native mandible. Making the bone cut through the socket of a tooth preserves an intact socket of the adjacent remaining tooth, improving the likelihood of viability. Fabrication of the neomandible (usually from fibula) to match the resected mandible requires knowledge of esthetics, geometry and mechanics. We do not recommend the use of a reconstruction plate to hold the free flap in position. The finer and esthetic aspects of the reconstruction are lost by using the relatively crude means of bending the reconstruction plate to the contour of the mandible. It is preferable that multiple osteotomies be performed in the fibula to create the necessary angulation, curvature, and height of the osseous free flap to exactly match the resected part of the mandible. The osteotomized segments of the free flap are retained in position with several miniplates and screws. Similarly, the reconstructed free flap is fixed to the native segments of the mandible with several miniplates and screws (Fig. 5.6). Custom made commercial planning devices are now available to give guides and molds for the exact sites of osteotomies to create the neomandible for perfect reconstruction. It also does away with guess work and minimizes operating room time.

MANAGEMENT OF THE MANDIBLE: MARGINAL MANDIBULECTOMY When there is no gross bone destruction but tumor is either adherent to or in close proximity to the mandible, a marginal mandibulectomy may be

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performed. Examples of these situations are tumors of the alveolar process or gingiva, buccal mucosa, or floor of the mouth. There are several anatomic and technical issues that must be considered when performing an anatomically, oncologically and structurally safe marginal mandibulectomy. The primary blood supply to the mandible is the inferior alveolar artery, which is located in the mandibular canal. In addition, secondary blood supply is provided from the periosteal blood vessels. The distance between the lower border of the mandible and the alveolar canal in the adult dentate mandible is approximately 11 mm. Therefore, an alveolectomy or an oblique marginal mandibulectomy (including the alveolus and lingual plate of the mandible) can be safely performed, preserving the alveolar canal and, thus, the blood supply to the remaining mandible (Figs 5.7A to D).

A

B Figs 5.7A and B

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C

D Figs 5.7A to D: Design of marginal mandibulectomy bone cuts to maximize preservation of blood supply and minimize risk of pathologic fracture.

However, with increased patient age, the alveolar process recedes and the superior border of the alveolus comes closer to the alveolar canal. Accordingly, in the elderly, edentulous patient, the mandibular canal is nearly at the alveolar ridge. In such patients, the likelihood of performing a safe marginal mandibulectomy is not high. The alveolar canal and, thus, the inferior alveolar artery are invariably included in the marginal mandibulectomy specimen, thereby sacrificing the primary endosteal blood supply to the remaining mandible. In addition, if a lower cheek flap is elevated for access, that aspect of the periosteal blood supply to the mandible is also compromised, making avascular necrosis of the remaining mandible more likely. This can eventually lead to pathologic fracture during the postoperative period. The risk is higher in previously irradiated patients. Therefore, marginal mandibulectomy in a previously irradiated edentulous patient is contraindicated.

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Fig. 5.8: When a marginal mandibulectomy is performed in an edentulous patient, with minimal remaining bone height, the risk of fracture can be reduced by using a low-profile miniplate to support the remnant mandible which will be subjected to masticatory forces.

On the other hand, when a marginal mandibulectomy is performed in an edentulous patient who has not undergone radiation, mechanical support to the remaining mandible should be strongly considered, to minimize the risk of fracture. This is easily provided by the use of a miniplate that supports the region of the angle of the mandible (the most vulnerable site for fracture, where the body and ramus are subject to masticatory forces). A long miniplate should be used, with screws to stabilize the plate, in the ascending ramus of the mandible and in the body of the mandible, extending well anterior to the angle (Fig. 5.8). Repair of the lining and soft tissue defect after marginal mandibulectomy can be accomplished by: (1) primary closure; (2) skin graft; or (3) free flap. If sufficient mucosa of the floor of the mouth and the buccal region is available, a primary closure of the mucosa can be performed over the marginally resected mandible. However, such a closure must be without tension, otherwise the suture line will break down, exposing the bone and causing delay in healing. If mucosal loss will not permit primary closure, a skin graft or a free flap will be required. A split-thickness skin graft will heal over the marginally resected mandible as long as it is properly retained in position. This may require circummandibular retention sutures to secure a bolster over the graft (Fig. 5.9). If a free flap is used, a fasciocutaneous radial forearm free flap is the best choice.

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Fig. 5.9: Depiction of circummandibular retention sutures to reliably secure a bolster over a skin graft placed over a marginal mandibulectomy site.

MANDIBULOTOMY In general, large tumors of the posterior third of the tongue (T2 or T3) and other large tumors of the oropharynx that were not accessible for resection through the oral cavity were approached in the past by use of composite resection (Commando operation). The adjacent, uninvolved mandible was resected to allow access to the oropharynx for resection of the primary tumor. This approach created significant esthetic and functional morbidity. Therefore, a mandibulotomy approach (mandibular swing) was developed to avoid the functional and esthetic sequelae of composite resection. Mandibulotomy provides the necessary exposure for resection of the tumor but preserves the mandibular arch. Mandibulotomy can be performed in one of three locations: (1) lateral; (2) midline; or (3) paramedian. Owing to the following reasons, lateral mandibulotomy is not preferred: • It gives limited exposure • It denervates distal teeth and skin of the chin, as the inferior alveolar nerve is transected • It devascularizes the endosteal blood supply to the distal mandible • The muscular pull on the two segments of the mandible is unequal, producing distraction at the site of mandibulotomy. • The mandibulotomy site is located within the lateral portal of radiation therapy (if the patient needs postoperative radiation therapy) A midline mandibulotomy avoids all of the above disadvantages of lateral mandibulotomy. It avoids denervation of the teeth and chin and does

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not devascularize the mandible. However, it has other sequelae that make the midline a less than ideal site for mandibulotomy. These are: • The space between the two lower central incisor teeth is narrow and the roots are often convergent, resulting in a high risk of exposing the roots of both central incisors and causing potential loss of one or both central incisor teeth. • Alternatively, to avoid exposure of the roots of both central incisor teeth, an extraction of one is often performed, and the mandibulotomy is performed through this socket. This alters the esthetic appearance of the lower teeth. • To get to the oropharynx through the paralingual extension, the geniohyoid, genioglossus, myelohyoid and hyoglossus muscles have to be divided and repaired. Repair is difficult and often incomplete. This causes significant delay in recovery of mastication, swallowing and speech. A paramedian mandibulotomy is performed between the lateral incisor and the canine teeth on the side of the tumor. It may sometimes be performed between the canine and the first premolar tooth, if these roots are more divergent on preoperative panoramic X-ray (Panorex). This approach avoids all the disadvantages of lateral and midline mandibulotomy and offers excellent exposure with minimal if any functional or esthetic sequelae. The advantages of paramedian mandibulotomy are: • Excellent exposure • It does not require extraction of any teeth • It does not cause loss of any teeth, since the roots of the lateral incisor and canine teeth diverge, offering a space to perform the mandibulotomy • It does not denervate or devascularize any part of mandible • The muscles inserting at the genial tubercle do not need to be divided • It does not cause any major disturbance in mastication, speech or swallowing, since only one muscle, the myelohyoid, needs to be divided and repaired • The mandibulotomy site does not have unequal traction on the segments of the mandible • The mandibulotomy site is not in the portals of radiation therapy. A paramedian mandibulotomy is performed through a midline lowerlip-splitting skin incision, which is curved laterally to the side of the lesion in the neck, at the level of the thyroid notch. Short cheek flaps are elevated on both sides of the midline to expose approximately 3 cm of the anterior surface of the mandible. To do this, an incision is placed in the gingivolabial sulcus, leaving approximately 5 mm of mucosa attached to the gingiva. The midline lip-splitting incision is connected to this incision, and all the soft tissues lateral to the anterior cortex of the mandible are elevated in the cheek flap. The cheek flap elevation extends laterally up to the mental foramen, which is at the location of the first to second premolar teeth, carefully preserving the mental nerve on the side of mandibulotomy (Fig. 5.10).

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Fig. 5.10: Design of a paramedian mandibulotomy. The mental nerve is preserved. The bone cut is placed in between divergent tooth roots. The osteotomy is angulated to minimize micromotion and lengthen the healing surface.

The mandibulotomy site is now marked out, with an angled cut to prevent cephalocaudad displacement of the two segments of the mandible after repair, which may lead to delayed union or malunion. The vertical cut begins at the alveolar process, between the lateral incisor and canine teeth, and extends downward, up to 3–5 millimeters below the apex of the roots of these teeth. At that point, the bone cut is angled 45° toward the midline (Fig. 5.11). The purpose of the angled bone cut is to increase the healing surface of the bone and to limit cephalocaudal displacement of the bone segments during healing. The bone cut is made through nearly 80% of the thickness of the mandible. At that point, two four-hole miniplates are used to predrill the screw holes on the two sides of the mandible. Placement of these screw holes and adaptation of the plates before the mandible is completely split allows preservation of accurate occlusion of the teeth at the time of repair. A biplane fixation should be used: one plate is adapted to the lateral cortex, and one plate is adapted to the lower border of the mandible. To prevent the drill holes from penetrating a tooth socket, the plate on the lateral cortex is placed below the level of the roots of the teeth. After the drill holes are made, the mandibulotomy is completed. The mandibular segments are retracted laterally, and a mucosal incision is placed in the floor of the mouth, leaving at least 10 mm of mucosa attached to the gingiva laterally. The mandible segments are retracted laterally to expose the myelohyoid muscle. The myelohyoid sling is divided exactly in the

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Fig. 5.11: Panoramic radiograph demonstrating the mandibulotomy performed in Figure 5.10.

middle, all the way up to the posterior border. This allows the mandibular segment to be swung laterally, providing a wide exposure of the oropharynx. Resection of the tumor and repair of the defect is performed in the usual manner. Repair of the mandibulotomy defect begins with mucosal closure in the posterior floor of the mouth, approximating the mucosa of the lateral border of the tongue to the mucosal cuff along the gingiva. Lateral retraction of the mandible should be avoided, as this closure progresses anteriorly; otherwise, the suture line will tear and cause dehiscence. Fixation of the two segments of the mandible is performed with the previously shaped miniplates at the site of the predrilled holes in the mandible. Both plates are screwed halfway through first, and then the screws are tightened, with the surgeon’s assistant holding the two segments of the mandible in perfect alignment. Once all eight screws are tightened, the two sides of the mandible are tested to see whether there is any motion at the site of mandibulotomy. If motion is detected, the screw holes are repositioned. If motion is detected even after repositioning of the screw holes, the two segments of the mandible are wired together by use of a prefabricated lingual/dental prosthesis. A postoperative panoramic X-ray of the mandible shows perfect alignment of the two segments of the mandible (Fig. 5.12).

OPTIMIZING THE LIP-SPLITTING INCISION Superior esthetic results are obtained by bringing the lip-splitting incision down the midline of the chin. In lighter-skinned patients without significant

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Fig. 5.12: Postoperative panoramic radiograph after paramedian mandibulotomy, demonstrating alignment of the mandible segments with two miniplates.

Fig. 5.13: In certain patients without significant submental skin laxity, the lip-splitting incision is designed with a geometric broken-line design, or a series of Z-plasties, to avoid cicatricial contraction.

laxity of the submental skin, we advocate using either a geometric brokenline configuration or a series of Z-plasties, to avoid cicatricial contraction (Figs 5.13 and 5.14). This incision is then transitioned to a lateral neck incision.

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Fig. 5.14: Postoperative result of the incision outlined in Figure 5.13.

If a neck dissection is not being performed and vessels do not require exposure for microvascular anastomosis—for example, in the case of a minor salivary gland tumor at the base of the tongue—the incision can be limited to simply the vertical lip-split and submental incision down to the hyoid bone, without a lateral extension.

PALATAL FENESTRATION FOR HARD PALATE TUMORS Small tumors (T1 and T2) of the mucosa of the hard palate, either superficial squamous cell carcinomas or minor salivary gland tumors, can be often removed without creating a through-and-through communication with the nasal cavity. Central palatal lesions can be removed completely without the need to sacrifice the uninvolved alveolar process. This is often the case for tumors of minor salivary gland origin. If the palatal bone is involved, then a throughand-through resection is required, creating an oronasal defect, which will require a dental/palatal obturator for speech and swallowing without nasal regurgitation. If, however, the palatal bone is not involved by the tumor and the bone appears normal on imaging studies, a through-and-through resection can be avoided. Although the bone is resected as deep margin of the specimen, the nasal mucosa is preserved. Clearly, this is preferable, since it will avoid the need for an obturator. To avoid a full-thickness defect, the mucosa of the floor of the nasal cavity must be preserved, without perforating it during resection. At the beginning

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of the operation, saline with epinephrine (1:100,000) is bilaterally infiltrated in the submucosal plane of the floor of the nasal cavity. A long lumbar puncture needle is used, and the submucosal plane of the floor of the nasal cavity is entered through the anterior nostril, hugging the upper surface of the palatal bone. This hydrodissection creates a pseudoplane between the bone and the mucosa of the floor of the nasal cavity. The resection then begins perorally, with a circumferential mucosal incision around the tumor. With a power saw or drill, the bone is scored through nearly 90% of its thickness. With a small osteotome, the bone is fractured at one place to allow entry to the previously created plane between the bone and the nasal mucosa. By use of a periosteal elevator, the palatal bone is dissected off the undersurface of the nasal mucosa. Finally, using the osteotome, the bone is fractured circumferentially, and the specimen is removed. Hemostasis is secured, and a Xeroform gauze packing is placed in the surgical defect. A temporary dental obturator is required to hold the packing in place. The dental obturator is required for several weeks, until the defect granulates in and is covered by palatal mucosa.

REPAIR OF THE CENTRAL PALATAL DEFECT Small through-and-through defects in the hard palate can be repaired by use of a mucoperiosteal or myomucosal flap from the soft palate; the flap is based on the vascular pedicle from one or both greater palatine arteries. This can be performed at the time of resection or secondarily. The ability of such a reconstruction to completely obliterate the oronasal defect depends on the size and location of the palatal defect (see Fig. 3.5). Large and more anteriorly located defects are difficult to repair in this manner and are most effectively managed by use of a dental obturator.

Chapter Larynx, Hypopharynx and Trachea

6

LOW-STAGE TUMORS A dramatic change in the surgical management of tumors of the larynx and pharynx has taken place during the last 25 years. Selected early-stage tumors (T1 and T2) of the supraglottic larynx and hypopharynx are increasingly managed by endoscopic laser resection. Similarly, early-stage lesions of the glottic larynx (T1 and T2) are managed either by external radiation therapy or by endoscopic laser surgery (see Chapter 11). Thus, open partial laryngectomy for both supraglottic and glottic tumors is now used rarely and for very select patients. These are patients who are not suitable for endoscopic surgery (because of trismus or cervical spine deformities, such that adequate exposure of the larynx is not feasible) and who are also not candidates for radiation therapy (previous radiation to the neck) or are undergoing salvage of persistent or recurrent cancer after radiation therapy. To ensure that successful outcomes are achieved in patients undergoing conservation laryngeal surgery after failure of radiation therapy, extremely rigid selection criteria must be met. These criteria are: • The index tumor (i.e. the tumor before radiation therapy) was suitable for partial laryngectomy • The persistent or recurrent tumor is not larger or more extensive than the tumor at initial presentation • There is no cartilage destruction • Soft tissue, skin and mucosa of the larynx and soft tissue in the central compartment of the neck in the irradiated field are suitable for partial laryngeal surgery, with the anticipation of satisfactory healing. In the literature, the reported experience with all conservation surgical procedures (supraglottic partial laryngectomy, vertical partial laryngectomy, and supracricoid partial laryngectomy) for laryngeal cancers in which radiation therapy has failed is limited. However, with stringent selection criteria, these operations can be performed successfully, and excellent local control rates can be achieved.

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ADVANCED LARYNGEAL TUMORS Advanced tumors of the larynx (T3 and T4), particularly those requiring total laryngectomy, are now managed in nearly all patients with a larynxpreservation treatment program of sequential or concurrent chemotherapy and radiation therapy. Excellent rates of larynx preservation have been reported from several well-controlled randomized clinical trials, and thus, these treatment programs have become the standards of care for laryngeal and hypopharyngeal cancers that require total laryngectomy. It follows that upfront total laryngectomy is used only in very select circumstances. These are: • Locally advanced cancers of the larynx or hypopharynx with cartilage destruction (T4a) • Select cases with extensive invasion of the base of the tongue from a laryngeal primary cancer • Select cases with extensive hypopharyngeal carcinoma extending to the postcricoid region or the cervical esophagus • Patients with a dysfunctional larynx for whom an organ-preservation protocol will not preserve a functioning laryngopharynx • Cancers of nonsquamous histologic profile, such as those of minor salivary gland origin, or soft tissue sarcomas • Patients unable to receive chemoradiation therapy. It must be kept in mind that 20–40% of patients receiving chemoradiation treatment for larynx preservation will not respond to treatment, will experience locoregional recurrence, or will develop a dysfunctional laryngopharynx, thereby requiring salvage surgery. These patients present a unique set of circumstances requiring special considerations in the salvage surgical management of their persistent or recurrent cancer. The issues to be consi­ dered in the management of these patients are: • The diagnosis of persistent tumor may sometimes be difficult. Persistent disease may be submucosal, and superficial mucosal biopsies may not confirm the histologic diagnosis. • Although a positive positron emission tomography (PET)/computed tomography (CT) scan finding substantially raises the suspicion of persistent tumor, the standardized uptake value (SUV) on the PET scan is often borderline, making the scan findings equivocal. • Soft tissues and skin of the neck have significant postchemoradiation changes and compromised vascularity, leading to poor healing and an increased risk of wound breakdown and fistula formation. • Serious consideration should be given to bringing in nonirradiated vascularized tissue to buttress the pharyngeal suture line. This may take the form of a pectoralis major muscle flap or a free radial forearm flap. • Laryngectomy incisions should be planned in such a fashion as to minimize the risk of wound breakdown.

Larynx, Hypopharynx and Trachea

TOTAL LARYNGECTOMY OR PHARYNGOLARYNGECTOMY A successful total laryngectomy or pharyngolaryngectomy results in primary healing of the wound, with satisfactory restoration of swallowing and a sufficient “pharyngeal reservoir” to permit successful rehabilitation of speech through a tracheoesophageal voice prosthesis performed either primarily or secondarily. To accomplish this goal, several technical issues must be considered.

Incision Several incisions have been described for performance of a total laryngectomy. These are described below.

Midline Vertical Incision A midline vertical incision starting at the level of the hyoid bone and ending at the upper end of the permanent tracheostome has been used in the past. This incision is poorly designed, as it makes any extension of the incision for a neck dissection or any reconstruction with a flap extremely difficult. In addition, if the pharyngeal suture line breaks down, resulting in a fistula, the salivary leakage drains directly into the tracheostome, leading to aspiration. Therefore, this incision is not recommended (Fig. 6.1).

Fig. 6.1: Incisions for laryngectomy, historical. Midline vertical incision—not recommended.

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Apron Incision An apron-shaped (U-shaped) incision is sometimes used for laryngectomy. This incision begins at the level of the digastric tendon on one side and ends at the digastric tendon on the other side, incorporating the upper half of the tracheostome at the apex of the incision. Although this incision provides adequate exposure for laryngectomy, it is also poorly designed, owing to a number of reasons. The blood supply to the apex of the apron-shaped skin flap of the neck, near the tracheostome, is the poorest, since it is derived from the peripheral branches of the facial artery in the submental region, in a retrograde fashion. This incision often leads to skin necrosis at the midpoint of the incision, and problems with healing of the tracheostome. In addition, if neck dissection is required, the incision does not provide adequate exposure of the posterior triangle, and a lateral extension may be required. Insertion of a regional flap, such as a pectoralis major myocutaneous flap, for reconstruction of the pharyngoesophageal defect is difficult. If the pharyngeal suture line breaks down, resulting in a fistula, the salivary drainage accumulates under the flap and, by gravity, drains at the lower end of the skin suture line into the tracheostome. For all of these reasons, we do not recommend this incision (Fig. 6.2).

“H” Incision An H-shaped incision is sometimes used for laryngectomy and bilateral neck dissections. Although this incision provides excellent exposure of the lateral

Fig. 6.2: Incisions for laryngectomy, historical. Apron incision—not recommended.

Larynx, Hypopharynx and Trachea

Fig. 6.3: Incisions for laryngectomy, historical. H-incision.

neck for neck dissections, the skin surrounding the tracheostome in the lower flap has precarious blood supply, putting it at an increased risk of necrosis. Therefore, we do not recommend this incision (Fig. 6.3).

Single Transverse Incision This is the ideal incision for laryngectomy with or without unilateral or bilateral neck dissection. The incision is placed at the level of the thyrohyoid membrane and is extended laterally on one or both sides, as far as necessary. The incision is anatomically sound, since the blood supply to the skin flaps is robust (derived from the facial and occipital arteries for the upper flap and from the internal mammary and transverse cervical arteries for the lower flap). The tracheostome is made in the suprasternal notch, excising a disc of skin measuring approximately 2.5 cm in diameter. To maximize the blood supply to this bridge of tissue, care must be taken to keep a distance of at least 3 cm between the neck incision and the upper border of the tracheostome (Fig. 6.4). If the pharyngeal suture line breaks down, leading to a fistula, the accumulating saliva can be drained to the exterior by opening the skin incision directly at that site, ideally at a lateralized location away from the tracheostome. This allows the tracheostoma to remain uninvolved with the fistula. Insertion of a pectoralis flap for reconstruction or as a buttress to the suture line can be easily performed by raising the neck and chest skin flaps

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Fig. 6.4: Incision for laryngectomy. Single transverse incision (preferred).

over the clavicle, on the side of the flap. For insertion of the flap, the addition of a vertical “trifurcation” incision is generally not necessary to transpose the pectoralis flap.

PHARYNGEAL CLOSURE Attention to detail in the closure of the pharynx after laryngectomy is crucial to (1) prevent wound breakdown and fistula formation; (2) prevent pharyngoesophageal stricture; and (3) create a wide pharyngoesophageal junction (neogullet) to provide a large enough reservoir of air to facilitate speech restoration. When sufficient mucosa of the base of the tongue and esophagus is available, a primary closure can be easily performed. Ideally, the closure of the pharyngoesophageal defect should be performed with a transverse linear closure. This is accomplished with interrupted inverting absorbable sutures. To complete this without tension, a suture is initially placed in the midline of the mucosal edge of the base of the tongue and in the midline of the anterior wall of the esophagus. This permits the opening to be divided into two halves. Each half of the opening is closed with another suture in the middle of the defect on one side, further dividing the opening into two halves. This is repeated on the opposite side. The opening is thus divided into four equal segments, which distributes the tension and mucosal surfaces of the base of the tongue and esophagus equitably throughout the suture line. A watertight closure is completed.

Larynx, Hypopharynx and Trachea

A vertical closure or a T-shaped closure should be avoided. The vertical closure increases the risk of stricture formation, and the T-shaped closure increases the risk of suture line breakdown at the trifurcation of the T closure. Similarly, if there is tension on the suture line, a primary closure should not be attempted, as it will lead to wound breakdown and fistula formation. In situations in which a tension-free primary closure in a transverse fashion is not feasible, repair of the pharyngoesophageal defect should be performed with a regional myocutaneous flap or a free flap as a “patch.” Compromised vascularity of the mucosa and soft tissues of the pharyngoesophageal region caused by previous radiation therapy or chemoradiation therapy also increases the risk of poor healing and wound breakdown. In these situations, the risk of fistula formation is higher, even if the transverse primary closure is performed in a tension-free manner. To prevent wound breakdown, the suture line should be buttressed with nonirradiated vascularized soft tissue. This is best provided by use of a pectoralis muscle flap or a free flap. Using this tissue layer provides new blood supply and protection to the suture line, as well as to the carotid artery. A pectoralis myocutaneous flap or fasciocutaneous free flap may be used to patch or buttress the pharyngeal closure. If this approach is chosen and the pharynx is able to be closed primarily in a transverse, linear fashion, the flap can be used to buttress the pharyngeal suture line. If the pharyngeal closure is compromised by either extensive tension or poor tissue quality, it is preferable to patch the pharyngeal defect with the regional or free flap.

TRACHEOESOPHAGEAL PUNCTURE Restoration of speech by means of tracheoesophageal puncture (TEP) and voice prosthesis has now become the standard of care for patients undergoing total laryngectomy. The question remains, however, whether the TEP should be performed primarily, at the time of total laryngectomy, or secondarily, at a later date. There is not widespread agreement in the head and neck surgery community on this issue, and practices vary significantly. In our practice, the indications for primary TEP are the following: • The area of the tracheostome has not been subjected to radiation therapy • An adequate tracheostome can be created with a beveled shape (a longer segment of the posterior wall of the trachea is available, compared with the anterior wall) • The pharyngoesophageal suture line (either by primary closure or with a flap) is at least 2 cm cephalad to the upper border of the tracheostome. On the other hand, a primary TEP is not recommended if: • The area of the tracheostome has been previously irradiated or if postoperative radiation therapy is planned

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•

A free flap is used for circumferential reconstruction of the pharyngoesophageal region • A gastric pull-up is performed for reconstruction • Extensive dissection is performed in the tracheoesophageal plane, separating the membranous trachea from the esophagus • The tissues near the tracheostome appear devascularized, scarred, and not healthy, raising the risk for wound breakdown. The use of primary TEP in patients who have previously received radiation therapy is highly variable among different centers. The rationale for delaying TEP in these cases is to reduce the high risk of pharyngocutaneous fistula.

TRACHEAL RESECTION The indications for resection of the trachea are: • Primary tracheal tumors • Secondary invasion of the trachea from cancers of the thyroid or esophagus • Tracheal stenosis Resection of the trachea for stenosis usually requires a circumferential, segmental or sleeve resection, since strictures occur as a result of concentric narrowing of the lumen. Often these involve a short segment of the trachea (3–4 cm), and primary end-to-end anastomosis can be easily performed. However, circumferential involvement is rarely seen in primary tumors of the trachea or in secondary invasion by thyroid or esophageal cancer. In these situations, accurate assessment of the extent of invasion is crucial to determine the extent, feasibility, and method of reconstruction to be used. Radiographic imaging is usually performed with CT or MRI, which shows the extent of tumor invasion in three dimensions. In addition, suspension laryngoscopy and tracheoscopy, under general anesthesia with jet ventilation, is necessary for adequate assessment of the intraluminal surface extent of the tumor. This requires assessment of the longitudinal (cephalocaudad) and circumferential extent of the tumor. Careful delineation of a cervical tracheal stenosis often is most straightforward via suspension laryngoscopy. A rigid laryngoscope can be carefully suspended, permitting passage of either a rigid Hopkins rod telescope or a flexible bronchoscope. We often favor inserting a smaller, anterior commissure laryngoscope just beyond the vocal folds to provide excellent exposure to the subglottis and proximal trachea. If performed judiciously, this can be accomplished with no sequelae to the glottic larynx. When examining the tracheal stenosis under jet ventilation, it is critical that the Hunsaker catheter or method of delivery be maintained entirely within the supraglottis. Jet ventilation must not be delivered beyond the area of stenosis, as lack of egress of air carries a very high risk of pneumothorax.

Larynx, Hypopharynx and Trachea

Fig. 6.5: Location of hyoid bone cuts (solid black lines) when performing a suprahyoid laryngeal release to facilitate tracheal resection and reanastomosis.

If the length of resection is less than 5 cm, a circumferential segmental resection is recommended. Primary end-to-end anastomosis can be easily performed for a defect of this length. If necessary, to avoid tension on the suture line, additional length can be gained by use of a supraglottic laryngeal release. This entails detaching all the central suprahyoid muscles from the hyoid bone. By the use of an electrocautery device, the muscular attachments at the central portion of the upper border of the hyoid bone, between the lesser cornua, are detached. The hyoid bone can then be divided lateral to the lesser cornua. The digastric muscle slings are left intact (Fig. 6.5). Care should be exercised as one approaches the greater cornua of the hyoid bone laterally, to avoid inadvertent injury to the lingual artery, hypoglossal nerve, and internal laryngeal branch of the superior laryngeal nerve. Once all these muscles are detached, the larynx will drop downward and give approximately 2–3 cm of length for primary anastomosis of the trachea. To avoid devascularizing the distal segment of the trachea, mobilization of the distal segment of the trachea should be minimal, as its blood supply is derived from the branches of the bronchial arteries, which run parallel to the trachea. Therefore, the distal tracheal stump is mobilized using gentle finger dissection in the superior mediastinum only on the trachea’s anterior surface; the temptation to dissect laterally along the trachea should be

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resisted. Further reduction in tension on the suture line is obtained by partial flexion of the neck. Once it appears that the two segments of the trachea can be approximated easily, anastomosis is begun. This is performed with long-lasting absorbable sutures such as 2-0 Vicryl, with all knots external to the trachea. The posterior half of the suture line (membranous trachea) is completed first. The remaining sutures are placed close enough to each other to secure a watertight anastomosis. This is checked in the following manner: The surgical field is flooded with saline, to immerse the trachea in saline. The anesthesio­ logist is asked to deflate the balloon of the endotracheal tube and ventilate the patient with an Ambu bag. If no air bubbles are observed leaking from the suture line, the anastomosis is secure. On the other hand, if air leak is observed, additional sutures are placed to secure an airtight suture line. The neck is kept in partial flexion, with a heavy nylon or silk suture between the skin and soft tissues of the chin and the presternal region (if possible, this suture is placed through the periosteum of the sternum and of the mentum). The “guardian stitch” serves to provide partial flexion, and more importantly, to avoid neck extension. The neck should not be flexed more than 15-30 degrees. The patient should be extubated as soon as spontaneous breathing upon recovery from anesthesia is observed. A nasogastric feeding tube is required for 2–3 days; thereafter, the patient is able to tolerate oral feedings. The suture keeping the neck in flexion is retained for at least 2 weeks. At that point, the tracheal anastomosis is healed, and a normal airway is established. A tracheostomy is not necessary and should not be performed. When a longer segment of the trachea is involved by the tumor and a primary anastomosis is not possible (after resection of a segment of the trachea), a very detailed assessment of the circumferential extent of the tumor is necessary, to plan resection and reconstruction. This may involve partial resection of the tracheal wall (window resection) and reconstruction with tracheal rotation or a regional or free flap, or a thoracic procedure such as bronchial reimplantation.

Chapter

The Neck

7

INTRODUCTION Significant advances have been made during the last three decades in surgery of the neck, particularly for metastatic carcinoma. These advances have been possible largely due to improved understanding of the biology of epithelial cancers of the head and neck, patterns of neck metastases, and sequential progression of metastatic spread from each primary site. First-echelon lymph nodes are identifiable for nearly all primary head and neck cancers. In addition, the development of sentinel lymph node biopsy techniques for cutaneous cancers such as melanoma and Merkel cell carcinoma has largely avoided the need for elective comprehensive neck dissections for patients at risk of metastatic lymph nodes. The accuracy of sentinel lymph node biopsy for cutaneous melanoma approaches 98%. Therefore, the finding of a sentinel lymph node with no evidence of metastasis on pathologic analy­sis identifies patients who are very unlikely to benefit from an elective nodal dissection. These developments have allowed the evolution of operative procedures that are less morbid, equally oncologically effective, and functionally better and that produce more esthetically pleasing results.

LYMPH NODE BIOPSY When a clinically or radiologically suspicious lymph node is identified in the neck, tissue diagnosis by either cytologic or histologic analysis is necessary. Ideally, a fine needle aspiration biopsy is performed first. In general, a 25-gauge needle is used, and multiple passes (generally without applying suction) are performed to obtain the necessary sample for cytologic interpretation. If the sample is not satisfactory or is nondiagnostic, a fine needle aspiration biopsy may be repeated once more. If the results of this remain unsatisfactory or indeterminate, a core needle biopsy may be helpful in some cases. Often, however, an open biopsy is required at this point. Similarly, an open biopsy is often requested for accurate diagnosis of lymphoma, owing to the need to examine architecture. In either case, if the lymph node is small

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Technical Variations and Refinements in Head and Neck Surgery

Fig. 7.1: Poorly placed lymph node biopsy incisions which create challenges for subse­ quent neck dissection. In this example, biopsy of a level II lymph node at the angle of the mandible (hashmarked line) was done with an incision that could not be incor­ porated into the subsequent neck dissection incision (solid line).

(< 2 cm), it is generally preferable to perform an “excisional” biopsy and remove the entire lymph node. On the other hand, if the lymph node mass is large, an “incisional” biopsy is preferable. It must be kept in mind that the principal objective is obtaining diagnostic material, rather than extirpating the entire nodal mass, which is not necessary if doing so would unnecessarily endanger local structures. When planning an open biopsy, the location of the incision is critical. The importance of this cannot be overstated. Improper placement of the biopsy incision will create a situation wherein a subsequent neck dissection incision cannot incorporate the biopsy scar. An example of such poorly placed incision is shown in Figure 7.1. Therefore, it is crucial to place the biopsy incision in such a fashion that it can be easily extended or incorporated into a subsequent neck dissection incision.

NECK DISSECTION Incision A variety of incisions for neck dissection have been described in the literature. Each of them claims superiority, either for better exposure; for extension of the operation to the oral cavity, larynx, pharynx, thyroid, etc.; for improved esthetic outcome; or for ease of surgery. None of these incisions fulfills all the criteria for an ideal incision for neck dissection.

The Neck

Fig. 7.2: Incisions for neck dissection (preferred). From top left to bottom right, selec­ tive neck dissection; parotidectomy and neck dissection; thyroidectomy and lateral neck dissection; thyroidectomy and bilateral neck dissections; bilateral comprehensive neck dissections (lateral and anterior views).

In our opinion, the ideal incision for neck dissection is a single transverse incision along a midcervical skin crease (below the beard line in men). For additional exposure to the submental region, the incision may be extended across the midline. For bilateral dissections, it can be extended along the same crease to the opposite side of the neck. The incision may be made as long as is necessary to facilitate exposure of the lateral neck up to the mastoid process or down to the supraclavicular fossa. Surgery for primary tumors of the larynx, pharynx and thyroid can be performed through the same incision. For oral cancer requiring mandibulotomy or mandibulectomy, a vertical limb of the incision may be placed in the midline, splitting the lower lip (an inverted T incision). The incision provides excellent exposure, is esthetically superior, and rarely causes skin flap loss, even in a postchemoradiation setting. The selection of the skin crease for placement of the incision varies from patient to patient, depending on the location of natural skin creases, additional primary sites requiring surgery (lower incisions for concomitant thyroid surgery), or the need for tracheotomy (in which case a higher incision is used) (Fig. 7.2).

EXTENT OF NECK DISSECTION On the basis of accumulated knowledge of patterns of neck metastases, a variety of modifications in neck dissection have been developed. These are generally described under two broad categories: (1) comprehensive, where all five levels of lymph nodes in the lateral neck are dissected; and (2) selective,

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where only a select group of lymph node levels are dissected. Several operations are described under these two broad categories.

Comprehensive Neck Dissections • • • •

Classical radical neck dissection Modified comprehensive neck dissection, Type I (only one structure, the accessory nerve, is preserved) Modified comprehensive neck dissection, Type II (two structures, the accessory nerve and the sternocleidomastoid muscle, are preserved) Modified comprehensive neck dissection, Type III (three structures, the accessory nerve, the sternocleidomastoid muscle and the internal jugular vein, are preserved)

Selective Neck Dissections • Supraomohyoid neck dissection (levels I, II and III) • Jugular node or lateral neck dissection (levels II, III and IV) • Anterolateral neck dissection (levels I, II, III and IV) • Posterolateral neck dissection (levels II, III, IV, V and suboccipital nodes) • Central compartment neck dissection (levels VI and VII) These types of neck dissection are well described, and this terminology is widespread. However, in the contemporary nomenclature for neck dissection, it is most preferable to use the terms radical neck dissection or modified radical neck dissection (specifying the structures preserved and sacrificed) or selective neck dissection (specifying the nodal levels removed).

PRESERVATION OF THE MARGINAL MANDIBULAR BRANCH OF THE FACIAL NERVE The marginal mandibular branch of the facial nerve can be easily injured during elevation of the superior subplatysmal flap. The surgeon must remain cognizant of the location of the nerve ramus, which runs in the plane of the fascia of the submandibular gland. In young patients, the nerve runs at the level of the inferior margin of the mandible; however, particularly in older patients, a ptotic submandibular gland can displace the nerve inferiorly. As the flap is elevated, dissection must be kept as close as possible to the platysma muscle. The nerve can then be identified as it dips just below the lower margin of the mandible, running in the fascia of the submandibular gland. Alternatively, the nerve can be identified by careful dissection of tissue at the angle of the mandible, where the nerve dips below the inferior margin of the mandible. If all else fails, the cervical branch of the facial nerve can be traced retrograde to identify the marginal mandibular branch. Once identified, it can be transposed cephalad.

The Neck

Alternatively, the facial vein can be ligated and reflected superiorly together with the fascia of the gland, protecting the nerve (which runs superficial to the vein) in a soft tissue envelope—this has been called the Hayes Martin maneuver. In this approach, the submandibular gland fascia is incised low on the gland and dissected superiorly together with the nerve. However, this maneuver precludes dissection of perivascular lymph nodes, and it is preferable to dissect these in patients with oral cavity primary cancers (Figs 7.3A and B).

A

B Figs 7.3A and B: (A) Identification of the marginal mandibular branch of the facial nerve during elevation of the superior skin-platysma flap; (B) Alternatively, the facial vein can be divided and elevated to protect the marginal mandibular nerve.

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PRESERVATION OF SKIN SENSATION When performing any of the modified comprehensive neck dissections or selective node dissections, the cutaneous branches of the cervical roots should be carefully preserved. The plane of dissection in the posterior triangle is just superficial to the cutaneous nerves. Since there are no lymph nodes located posterior to the plane of the cutaneous nerves, the cutaneous nerves can be safely preserved, retaining skin sensation and reducing the area of numbness in the neck. Clearly, if there are grossly enlarged metastatic nodes in the vicinity of the cutaneous nerves, they should be sacrificed, to avoid compromising the oncologic completeness of the operation.

PRESERVATION OF VASCULARITY OF THE ACCESSORY NERVE A significant number of patients undergoing comprehensive modified neck dissections or selective lateral node dissections develop weakness of the shoulder and some atrophy of the trapezius muscle, despite the anatomically preserved accessory nerve. This occurs as a result of circumferential dissection of the nerve during comprehensive neck dissections, or dissection of level IIB in selective node dissections. We do not recommend routine dissection of level IIB in patients undergoing anterolateral (levels I to IV) or supraomohyoid (levels I to III) nodal dissection in whom there are no grossly enlarged lymph nodes at level IIA. In the absence of gross metastatic disease at level IIA, the incidence of metastasis at level IIB is very low, close to zero. By avoiding level IIB dissection, the accessory nerve is not circumferentially dissected, preserving its vascularity and minimizing ischemic nerve dysfunction. Similarly, in patients undergoing comprehensive modified neck dissections, circumferential dissection of the nerve should be avoided, to preserve its vascularity as much as possible. The apex of level V, superior and posterior to the accessory nerve, can be safely left in situ, in most cases. There are essentially no lymph nodes of concern posterior to the accessory nerve at the apex of the posterior triangle, and metastases to the apex of level V are exceedingly rare. Therefore, the nerve should be left undisturbed in its fascial bed, keeping the nodal dissection anterior and inferior to the nerve in the posterior triangle. Preserving the vascularity of the nerve in this fashion minimizes ischemic nerve injury and subsequent shoulder dysfunction. Certainly, in the uncommon case of bulky metastatic disease along the accessory chain, dissection of the apex of level V may be required.

The Neck

SELECTIVE NECK DISSECTION IN THE POSTCHEMORADIATION SALVAGE SETTING A majority of patients with laryngeal or pharyngeal squamous cell cancer, with metastatic lymph nodes in the neck, who are treated with chemoradiation therapy respond well and show no evidence of residual disease, which is confirmed by a negative clinical examination and negative imaging studies, such as post-treatment contrast-enhanced computed tomography (CT) and positron emission tomography (PET)/CT scan. In these patients, planned neck dissection is no longer advocated, and the neck can be safely left to observation. However, a small group of patients with residual disease identified clinically or on imaging studies will require a salvage neck dissection. Some of these patients have nonviable tumor cells in fibrotic lymph nodes, and there is mounting evidence that residual disease, if present, is generally confined to the level of index nodal involvement. Therefore, the philosophy of “superselective nodal dissection”—essentially a nidusectomy—has evolved. In this setting, only the demonstrable gross abnormality is resected (in a monobloc fashion) and is subjected to pathologic analysis. Even when there is viable residual disease in this type of specimen, other lymph nodes are almost never involved. Thus, one may avoid the need for completion nodal dissection, as well as its potential complications and morbidity. Needless to say, if gross metastases are present after chemoradiation therapy or if multiple levels harbor involved lymph nodes, a comprehensive neck dissection (modified radical, radical or extended neck dissection) may be necessary.

Avoidance of Chyle Leak The thoracic duct is rarely encountered as a single structure and, in fact, is generally encountered as a series of distributaries. These branches will be identified low in level IV of the left side of the neck, below the transverse cervical vessels, very close to the phrenic nerve, running toward the internal jugular vein. Adequate exposure low in the neck is critical. The sternocleidomastoid muscle must be skeletonized all the way down to the sternal notch. This part of the neck dissection must be performed meticulously, from lateral to medial, ligating all soft tissue at the base of level IV between the phrenic nerve and jugular vein, regardless of whether branches of the thoracic duct are visible. After completion of the neck dissection, the integrity of the area can be confirmed by both the use of the Valsalva maneuver and the application of abdominal pressure. If a leak is visualized, the least traumatic option is to oversew it, taking care to avoid injury to the nearby phrenic nerve.

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CENTRAL-COMPARTMENT NODE DISSECTION The incidence of micrometastases from papillary carcinoma of the thyroid gland in the central-compartment lymph nodes is significant, approaching 30–50% in various reports. The advocates of elective central-compartment node dissection use this incidence to justify the elective operation. However, the prognostic implication or potential benefit to the patient remains to be proven. At the present time, there is no evidence that such a practice reduces the risk of recurrence or death in these patients. In addition, the operation carries significant morbidity, with a high incidence of permanent hypoparathyroidism and increased risk of injury to the recurrent laryngeal nerves. We therefore do not recommend elective central-compartment nodal dissection. On the other hand, when central-compartment lymph nodes are demonstrated on preoperative imaging (ultrasound or CT scan) to be grossly enlarged, a systematic central-compartment lymph node dissection should be performed to clear lymph nodes from levels VI and VII. This implies clearance of lymph nodes from the level of the hyoid bone superiorly to the innominate artery in the anterior superior mediastinum inferiorly, and from carotid artery to carotid artery. This encompasses clearance of lymph nodes from the pretracheal region in the midline and bilateral paratracheal and tracheoesophageal groove lymph nodes. Lymph nodes should be excised in a systematic fashion, medial, lateral, anterior and posterior to the recurrent laryngeal nerves (Fig. 7.4).

Fig. 7.4: A complete central compartment lymph node dissection, systematically

excising lymph nodes between the carotid arteries, from the hyoid bone to the innomi­ nate artery, preserving both recurrent laryngeal nerves.

The Neck

Such thorough dissection is necessary to prevent recurrence of disease in the central compartment of the neck. This extent of node dissection will often jeopardize the vascularity of the inferior parathyroid glands. If there is any concern about the viability of the inferior parathyroid glands, they should be implanted in the adjacent sternocleidomastoid muscle. The superior parathyroid glands generally retain an intact blood supply and can be easily dissected off and preserved with their blood supply intact. When this is performed, nerve monitoring may be useful for inexperienced surgeons or in patients with extensive nodal disease.

PLACEMENT OF SUCTION DRAINS Traditionally, suction drains are used after most types of neck dissections. They prevent hematoma and seroma formation and allow the skin flaps to adhere to the deeper tissues expeditiously. In general, these suction drains are introduced through separate puncture wounds in the lower part of the neck, in the supraclavicular region, or sometimes on the anterior chest wall in the infraclavicular location. In some patients, after removal of the drains, the puncture wound heals with a hypertrophic scar, leaving an obvious “nubbing” of scar, which is esthetically unpleasant (particularly in young women). We recommend that the puncture wounds to introduce the suction drains be placed through the skin overlying the mastoid process, posterior to the lobule of the ear, which is a relatively inconspicuous site. Regardless of how these puncture wounds heal, they are either not readily visible or can be covered with hair among women.

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Chapter Thyroid and Parathyroid Glands

8

INTRODUCTION

.

A steep increase in the incidence of papillary thyroid carcinoma has been observed in the US and around the world during the last 10–15 years. For the most part, this increase in incidence is attributable to tumors less than 2 cm in size, most of which have been incidentally discovered on ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography (PET)/CT scan performed for nonthyroid diagnoses. A majority of these small papillary cancers occur in younger women, and nearly all of them have an excellent prognosis. Because of excellent long-term outcomes and prognoses, attention has turned to the functional and esthetic sequelae of thyroid surgery. This has led to the improvisation of surgical techniques with smaller incisions in the neck, to endoscopic and video-assisted thyroidectomies, and even to transaxillary robotic thyroidectomies to avoid an incision in the neck.

THYROID LOBECTOMY OR TOTAL THYROIDECTOMY The traditional large, low cervical incision has been mostly abandoned, except for use in patients with large retrosternal goiters. Most patients with tumors 2–3 cm in diameter can easily undergo lobectomy or total thyroidectomy through incisions of 3–4 cm in length without the need for endoscopes or other advanced techniques. The placement of the incision is crucial to achieve the best esthetic outcome. The standard post-thyroidectomy incision and scar is demonstrated in Figures 8.1A and B. In general, female patients with large breasts should have the incision placed in a natural skin crease, as high as possible, to obtain the necessary exposure. In these patients, the incisions will be displaced inferiorly when they are upright. It is helpful to mark the incision on the patient’s neck in the preoperative holding area, with the patient sitting upright. Conversely, patients of average build should have the incision placed in a natural skin crease over or near the region of the cricothyroid membrane. The incision

Thyroid and Parathyroid Glands

A

B Figs 8.1A and B: (A) Incision outlined for thyroidectomy; (B) Long-term postoperative appearance of carefully placed incision for thyroidectomy.

should be equal in length on both sides of the midline, regardless of the location of the nodule(s). The platysma is divided, and upper and lower skin flaps are elevated. The skin flaps are retracted using fish hook retractors (short blunt metal hooks anchored on an elastic rubber band). Several steps of the operation have been modified to facilitate a safe, complete, meticulous, and essentially bloodless operation. Generous use of bipolar cautery is recommended. The operative steps should be followed in the following sequence:

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1. The strap muscle fasciae are divided in the midline, and the sternohyoid muscles are retracted laterally. 2. The sternothyroid muscle is divided as high as possible, which substantially enhances exposure of the superior pole, and then carefully dissected off the anterior surface of the gland and either excised or left pedicled inferiorly. Although this step is not universally necessary, it substantially enhances exposure in nearly every case. 3. Terminal branches of the superior thyroid artery and tributaries of the superior thyroid vein are each individually divided and ligated low on the gland, below the superior pole of the gland. The superior pole vessels should not be ligated en masse. This protects the external laryngeal branch of the superior laryngeal nerve. 4. The upper pole is retracted medially, and the superior parathyroid gland is identified, dissected off the thyroid, and carefully dissected laterally, preserving its blood supply, which is lateral to the parathyroid gland. 5. Dissection continues caudally, along the posterior capsule of the thyroid, in an extracapsular plane, to identify the inferior parathyroid gland, which is separated from the thyroid and retracted laterally, with its blood supply intact. 6. The lower pole vessels are dissected and divided, taking care to remain in a pretracheal plane, thereby mobilizing the lower pole while remaining well anterior to the location of the recurrent laryngeal nerve. 7. The thyroid lobe is retracted medially, and the recurrent laryngeal nerve is identified. The course of the nerve must be carefully ascertained proximally and distally. 8. All thyroid tissue at Berry’s ligament is meticulously dissected off the trachea, protecting the recurrent laryngeal nerve and ligating the terminal branches of the inferior thyroid artery. 9. The thyroid lobe and isthmus are peeled off the trachea, using either judicious cautery or cold steel dissection. 10. The pyramidal lobe is traced up to the hyoid bone and dissected off completely. 11. The contralateral lobe is dissected similarly, to complete the total thyroi­ dectomy. 12. The thyroid gland is meticulously inspected for retained parathyroid glands. 13. Absolute hemostasis is secured. 14. A drain is generally not required. 15. The wound is closed in layers. 16. The patient may be discharged the same day or stay overnight and go home the next morning. There is some variation among the practice of thyroidectomy. We believe that it is safest to routinely identify the recurrent laryngeal nerve during

Thyroid and Parathyroid Glands

every thyroidectomy. It is important to confirm integrity of the nerve before moving to dissect the contralateral thyroid lobe; if nerve integrity cannot be confirmed, the surgeon should carefully consider whether it is safe to perform the contralateral hemithyroidectomy. There are also a multitude of valid approaches to postoperative calcium management after total thyroidectomy, ranging from routine supplementation to selective supplementation based on serum calcium levels and/or postoperative rapid parathyroid hormone (PTH) measurements. Our approach has been to rely on the most cost-effective strategy, which is routine supplementation with over-the-counter calcium carbonate (serum calcium level is checked once at 12 hours postoperation, before discharge home). Calcium supplementation is then tapered off over the course of several weeks. This approach identifies nearly all patients who are going to develop significant postoperative hypocalcemia and require additional supplementation or hospitalization. However, a number of approaches have been described that work well.

THYROIDECTOMY AND NECK DISSECTION If a central-compartment or lateral neck dissection is required, the incision is extended along the same skin crease unilaterally or bilaterally, as needed. There is generally no additional exposure achieved by using a U-shaped incision that extends up to the mastoid process; however, this vertical extension produces an unsightly scar. Extension of the transverse incision along the same skin crease as far posteriorly as necessary to obtain the required exposure produces an excellent esthetic result (Fig. 8.2).

SURGERY FOR LARGE THYROID TUMORS AND RETROSTERNAL GOITERS Clearly, larger thyroid tumors and large retrosternal goiters require larger incisions. However, these incisions can still be located in natural skin creases close to the cricoid cartilage. In these operations, we generally recommend that both the sternohyoid and sternothyroid muscles be sacrificed bilaterally to enhance wide exposure. Thus, they are divided high, at the level of the cricoid cartilage superiorly and at the level of the sternal notch inferiorly. In so doing, the tightly packed large thyroid mass in the central compartment is “released,” facilitating subsequent dissection. Nearly all previously unoperated-on and benign retrosternal goiters can be removed in an en bloc fashion using the cervical approach. After transection of the strap muscles, the blood supply to the thyroid is sequentially and meticulously divided and ligated. This includes the vessels at the lower pole, which are carefully isolated by gentle finger dissection, mobilizing the goiter

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Fig. 8.2: Extension of the transverse thyroidectomy incision is adequate to provide

access for lateral neck dissection(s). A U-shaped incision curving upwards toward the mastoid tip is not recommended.

with gentle traction. Rough digital dissection can be hazardous and may lead to uncontrollable bleeding: it should be avoided. Gentle and meticulous digital mobilization and sequential division and ligation of the blood vessels result in safe delivery of the goiter. The entry of the recurrent laryngeal nerve should be identified at the cricothyroid joint, which is the most consistent landmark and is helpful in cases of goiter, where the nerve may be displaced in any direction. From this location, the nerve is followed caudally, as dissection of the goiter proceeds into the mediastinum. In cases of large goiters, it is difficult to preserve the blood supply to the inferior parathyroid glands. Therefore, efforts should be made to identify these glands and to reimplant them into the sternomastoid muscle. Management of a differentiated thyroid cancer with recurrent laryngeal nerve invasion depends on a number of factors, most importantly the pre­operative function of the nerve. A patient presenting with vocal cord paralysis is very unlikely to regain function of the nerve, even if it is preserved, and therefore there is little benefit to preserving the nerve in these situations. On the other hand, if the nerve is functioning preoperatively, we seek to remove all gross tumor from the nerve, leaving behind microscopic disease, which will be targeted with adjuvant therapy. This is performed with careful dissection, using a fine clamp. In some cases, the extent of tumor involvement precludes dissecting out the nerve anatomically intact. If the nerve is to be sacrificed, the integrity of the contralateral nerve should first be abso­lutely ensured.

Thyroid and Parathyroid Glands

NERVE MONITORING Routine use of intraoperative nerve monitoring is not necessary. However, this technique may be useful for a relatively inexperienced surgeon to identify and confirm the recurrent laryngeal nerve’s location and function. Additionally, even for experienced surgeons, nerve monitoring may be useful for the management of select patients undergoing surgery for recurrent cancer in a scarred field, as well as for patients with massive tumors in whom early identification of the nerve may be difficult or in whom extensive dissection of the nerve may lead to a loss of nerve conduction. In these cases, knowledge of loss of nerve conduction may influence the surgeon’s decision to move to the other side and dissect the contralateral nerve or not. In these respects, nerve monitoring is very much an adjunct to surgery, and not a substitute for the above-delineated principles of routine nerve identification and careful dissection. If nerve monitoring is performed a number of practical aspects can be helpful. • The anesthesiologist should use only short-acting paralytics for induction. • If working with anesthesiologists unfamiliar with the monitoring tube, the surgeon should personally verify appropriate placement of the electrodes at the level of the true vocal cords after positioning the patient and extending the neck. • Respiratory variation in the baseline electromyography (EMG) tracing will confirm correct tube placement. Tapping on the larynx can stimulate the nerve monitor, regardless of appropriate placement, and is therefore less reliable. • For the most part, the stimulator probe will be used at 1 mA. • Once the surgical field is open, test the nerve stimulator on strap muscles to confirm muscle twitch. • When stimulating tissue, a lack of signal should never be accepted as negative until a “positive control” is obtained by successfully stimulating the recurrent laryngeal nerve. • In cases where the recurrent laryngeal nerve has not been identified and a positive control is needed, it is straightforward to open the carotid sheath lateral to the thyroid lobe, expose the vagus nerve, and stimulate it, to confirm that the system is working properly. • At the completion of dissection on one side, the nerve should be stimulated as proximally as it has been dissected, to confirm intact stimulation. A loss of proximal nerve conduction (with intact distal conduction near the nerve insertion to the larynx) may indicate an unappreciated neuropraxia caused by stretching, clamp, or cautery injury and may influence the surgeon’s decision to operate on the contralateral lobe.

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•

Despite appropriate placement, the electrodes may still malfunction sometimes. In these cases, palpation of the cricothyroid joint during stimulation of the nerve at 1 mA will allow the surgeon to feel a definitive twitch of the larynx. We recommend that surgeons familiarize themselves with this “laryngeal kick” early on, so that this maneuver can be called on in cases in which the electrodes are not working.

PARATHYROID SURGERY Once a diagnosis of primary hyperparathyroidism is made by use of biochemical testing, the critical aspect of parathyroid surgery becomes preoperative localization. The modality or modalities used for preoperative localization are highly dependent on local expertise and surgeon pre­ference. These include nuclear medicine sestamibi scan, ultrasound, thin-slice contrast-enhanced CT scan, and dynamic 4D CT imaging. The goal of pre-operative localization imaging is to identify the precise location of the parathyroid adenoma and to facilitate minimally invasive surgery. Surgeons who perform high-volume parathyroid surgery are well served by learning skills for cervical ultrasound, which provides an unparalleled threedimensional sense of the location of the enlarged parathyroid gland.

MINIMALLY INVASIVE PARATHYROIDECTOMY If a single adenoma can be localized on preoperative imaging and if intraoperative PTH monitoring is available, a minimally invasive parathyroidectomy can be performed. In most cases, we prefer the lateral approach, as this is the most direct route to the parathyroid glands and as it minimizes the need for mobilization and retraction of the thyroid lobe. These explorations can be performed under general anesthesia or under local and regional anesthesia, with (or without) sedation, using described techniques of blocking sensory nerves along the posterior border of the sternocleidomastoid muscle as well as within the local field (Fig. 8.3). If local and regional anesthesia is chosen, parathyroidectomy can be comfortably performed with little or no sedation, and the patient is able to go home shortly after surgery. The incision is planned in a naturally occurring skin crease, is 2–3 cm in length, and extends from the midline on the side of the adenoma (Fig. 8.4). If an ultrasound machine is available in the operating room, it is very helpful to re-localize the adenoma on the table, and mark the incision directly overlying it. We mark the contralateral incision on the skin but do not use this incision unless it is needed for contralateral exploration. The incision is carried through the platysma, and the subplatysmal flaps do not need to be elevated. Dissection proceeds in the plane between the lateral border of the sternohyoid and sternothyroid muscles and the medial border of the sternocleidomastoid muscle. The middle thyroid vein does not universally

Thyroid and Parathyroid Glands

Fig. 8.3: Locations of local anesthetic injection (black Xs) for local and regional anesthesia for minimally invasive parathyroidectomy.

Fig. 8.4: Short, lateral incision for minimally invasive parathyroidectomy. The entire skin crease should be marked, in case of a need to extend the incision for bilateral parathyroid exploration.

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Fig. 8.5: Cross sectional view of the lateral approach to parathyroid glands, used

for minimally invasive parathyroidectomy. Here, a superior parathyroid adenoma is depicted. One retractor displaces the thyroid gland medially; a second retractor, the carotid artery laterally.

need to be ligated. With the thyroid lobe retracted medially and the common carotid artery retracted laterally, the adenoma is readily identified and removed en bloc (Fig. 8.5). Embryologic development dictates that an inferior parathyroid gland will be in the plane anterior to the recurrent laryngeal nerve and that a superior parathyroid gland will be in the plane posterior to the recurrent laryngeal nerve. Gentle, meticulous dissection is critical to avoid spillage of parathyroid tissue and possible subsequent development of recurrence. If slow, careful extracapsular dissection is performed, it is not necessary to routinely identify the recurrent laryngeal nerve. The superior parathyroid glands will invariably be located adjacent to the course of the nerve. Intraoperative PTH monitoring and frozen-section pathologic analysis are used to confirm removal of parathyroid tissue and completeness of surgery. The intricacies of intraoperative PTH monitoring are beyond the scope of this text, but, in general, the Miami criteria—which specify a PTH level decrease of greater than 50% into the normal range—are followed. If additional surgery is required, the ipsilateral gland can be explored through this same incision, and the incision can be extended.

FOUR-GLAND EXPLORATION AND SUBTOTAL PARATHYROIDECTOMY If preoperative imaging does not reveal a single adenoma, the patient may harbor multigland disease (either double adenoma or four-gland

Thyroid and Parathyroid Glands

hyperplasia), or imaging may simply have been falsely negative. Four-gland exploration may also be preferred in settings where intraoperative PTH testing is not available. If intraoperative PTH testing is available, we recommend determining PTH levels from both internal jugular veins, low in the neck, at the start of anesthesia, as doing so may be helpful in selecting a side on which to begin exploration. When a four-gland exploration is needed, a midline incision is used, rather than a shortened, lateral incision. The thyroid gland is approached from the midline of the strap muscles, as in thyroidectomy. As the thyroid gland is mobilized medially, the embryologic (anterior/posterior) anatomic relationships of the superior and inferior glands should be kept in mind. In four-gland explorations, we recommend identifying the recurrent laryngeal nerve, as doing so expedites safe exploration of the parathyroid glands. If an obvious adenoma is not encountered and the surgeon suspects four-gland hyperplasia, we recommend identifying and examining all four glands before resecting any of them. Once this is done, the diagnosis of fourgland hyperplasia should be confirmed visually, as no obvious adenoma has been identified. If a small adenoma is suspected, the affected gland can be resected, and intraoperative PTH levels are obtained. If four-gland disease is suspected and one or more glands become dusky in appearance or otherwise appear to be nonviable, it is preferable to resect these glands, in order to leave a viable remnant behind. In general, it is preferable to subtotally resect an inferior gland, as the inferior glands are more anteriorly located and easier to locate in the reoperative setting. In the patient with renal failure and secondary or tertiary hyperparathyroidism, the risk of recurrence is higher, and we recommend either subtotal resection of an inferior gland or total resection, with reimplantation in an easily accessible location, such as the brachioradialis muscle. In cases in which there is insufficient decrease in the PTH level and there is a “missing” gland, we use a number of approaches tailored to the deduced identity of the missing gland (superior vs inferior). If an inferior gland cannot be identified, we recommend performing a cervical thymectomy, dissecting free and removing nodal and thymic tissue from low in level VI and the superior mediastinum. Other locations for ectopic glands include a superior gland that has migrated inferiorly (these will be posterior to the nerve, in the tracheoesophageal groove, but lower in the neck), a gland nestled in the thyroid capsule, and, less commonly, a gland located in the carotid sheath or retroesophageal locations.

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Salivary Glands

9

SUPERFICIAL PAROTIDECTOMY Superficial parotidectomy with dissection and preservation of the facial nerve is the most common operation used for neoplasms located in the superficial lobe of the parotid gland. The operation is advocated for both benign and malignant tumors confined to the superficial lobe of the parotid gland, with normal facial nerve function. In general, this means tumors that are staged T1 or T2. There are several technical points that are crucial and important to follow for safe, smooth and expeditious conduct of this operation and to produce a pleasing esthetic and functional outcome.

Incision In older patients, who have lax skin and natural skin creases, a preauricular skin crease is selected for placement of the incision. The incision is made in the preauricular skin crease and curves around the lobule of the ear, on to the postauricular skin overlying the mastoid process, and then extends anteroinferiorly into an upper neck skin crease. This is the usual modified Blair incision. The lower end of the incision should not extend beyond the anterior border of the lower part of the parotid gland. On the other hand, in young patients and those lacking natural skin creases in the preauricular region, such an incision should not be used. In such cases, the incision should be modified to avoid a visible preauricular scar. The incision used in this setting is called a “tragal incision”. The incision begins at the upper end of the tragal cartilage, on the free edge of the tragus, up to the lobule of the ear. It is not necessary to carry the incision over to the posterior border of the tragus. The incision then continues on the junction of the lobule and preauricular skin, curves around the lobule of the ear in the skin overlying the mastoid process, and then follows an upper neck skin crease anteroinferiorly (Fig. 9.1). When this incision is used, extreme care should be exercised to not perforate the skin while elevating the skin flap over the tragus. There is no soft tissue between the skin and the tragal cartilage.

Salivary Glands

Fig. 9.1: Tragal incision for parotidectomy.

Fig. 9.2: Postoperative appearance of the incision used in Figure 9.1.

Therefore, the pretragal skin is elevated with the scalpel by sharp horizontal dissection, separating skin from cartilage up to a distance of 1 cm. To prevent perforation of the skin, use of electrocautery during elevation of this part of the skin flap should be avoided. The skin is quite thin and should be handled very delicately. Subsequent elevation of the skin flap can be easily performed using an electrocautery device. The esthetic impact of the tragal incision is minimal, with superb postoperative appearance (Fig. 9.2).

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For deep lobe parotid tumors, the incision is slightly modified. The standard superficial parotidectomy incision is generally not adequate in these cases. In these patients, exposure of the posterior belly of the digastric and stylohyoid muscles is required to gain access to the parapharyngeal space. Therefore, to expose the region of the stylohyoid window, the lower part of the incision is extended anteroinferiorly along the upper neck skin crease.

Elevation of Skin Flap Elevation of the anterior skin flap during superficial parotidectomy can be expeditiously performed with an electrocautery device. After the skin incision is made, the electrocautery device is used to deepen the incision through subcutaneous fat, before elevating the skin flap anteriorly. All subcutaneous fatty tissue should be preserved on the skin flap, such that the plane of dissection is immediately over the parotid fascia, since there is no parotid glandular tissue superficial to the parotid fascia. Preservation of all of the subcutaneous fat, leading to the use of a thick skin flap, is important to reduce the postoperative soft tissue deficit and esthetic deformity. Elevation of the skin flap can be performed safely and bloodlessly with the use of electrocautery, but care must be taken to avoid dissection anterior to the gland, as the facial nerve branches emerge from the parotid gland and run within the fascia of the masseter muscle; the nerve branches are visible in this layer and can be inadvertently injured, and this extent of dissection is not needed for parotidectomy. The inferior (cervical) portion of the skin flap is raised in a subplatysmal plane. The superior margin of the platysma will be encountered over the mandible. As the platysma is contiguous with the superficial musculoaponeurotic system of the face, it is found one layer superficial to the parotid fascia. Therefore, a transition in dissection plane must occur at the superior edge of the platysma. Once again, care must be taken to not extend dissection too far anteriorly, as the marginal mandibular branch of the facial nerve may be inadvertently injured after its exit from the parotid gland.

Management of the Great Auricular Nerve In most patients, the great auricular nerve emerges from the posterior border of the sternocleidomastoid muscle at Erb’s point. This location can be approximated on the skin using surface landmarks. A line is drawn from the mastoid tip to the angle of the mandible. A second line, orthogonal to and bisecting the first line, will intersect the posterior border of the sternocleidomastoid muscle at approximately Erb’s point. These landmarks are helpful in anticipating the location of the great auricular nerve branches during creation of the skin incision and raising of the subplatysmal flaps (Figs 9.3A and B). The great auricular nerve then wraps around the posterior border of the muscle, traverses its surface, and heads toward the superficial portion of the inferior parotid gland. The nerve is usually a single trunk that separates

Salivary Glands

A

B

Figs 9.3A and B: Surface landmarks (dotted black lines) helpful in identifying the

anticipated location of the greater auricular nerve, approximately 1 cm superior to Erb’s point.

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Fig. 9.4: Preservation of the posterior branch of the great auricular nerve is often feasible during parotidectomy.

into several branches over the surface of the parotid gland. Thus, it needs to be sacrificed as the parotid gland is mobilized and dissected away from the sternocleidomastoid muscle. However, in a significant minority of patients, the nerve bifurcates early on the surface of the sternomastoid muscle, with its posterior branch proceeding directly cephalad toward the mastoid tip. In these patients, the anterior branch of the greater auricular nerve is sacrificed, but the posterior branch can be preserved, thus retaining sensations for a significant portion of the auricle (Fig. 9.4). Therefore, during elevation of the skin flap, meticulous attention should be given to identifying the greater auricular nerve and determining whether it bifurcates early, thereby enabling preservation of its posterior branch.

Initial Dissection of the Parotid Gland Mobilization of the posterior border of the superficial lobe of the parotid gland can be easily performed using an electrocautery device, achieving excellent hemostasis and in an expeditious manner. To do this, the first step is to isolate the anterior border of the sternocleidomastoid muscle. Dissection proceeds along this border separating the superficial lobe, which is retracted anteriorly. To identify the posterior belly of the digastric muscle, the separation of the parotid gland from the sternomastoid muscle continues in a deeper plane. It is necessary to identify only the posterior belly of the digastric muscle at the level of the anterior border of the sternocleidomastoid muscle, and not more posteriorly. The digastric muscle is a key landmark, corresponding with the depth of the main trunk of the facial nerve.

Salivary Glands

Similarly, the superficial lobe of the parotid gland is dissected away from the cartilaginous portion of the external auditory canal by use of electrocautery, expeditiously and with excellent hemostasis. Care should be taken to avoid cauterizing the cartilage itself. However, to prevent transmission of electrical current or thermal injury to the facial nerve, the use of monopolar electrocautery should cease once the cartilaginous external auditory canal is separated but still slightly superficial to the plane of the posterior belly of the digastric muscle. At this point, bipolar electrocautery should be used for further division of tissue. A long Adson or fine tonsil clamp is used to dissect the parotid tissue, which is first cauterized with the bipolar cautery device and then sharply divided with a scalpel or fine scissors. This method of dissection provides excellent hemostasis and maintains a dry field.

Identification of the Main Trunk of the Facial Nerve The facial nerve exits the temporal bone through the stylomastoid foramen; therefore, the extracranial portion of the facial nerve has a constant anatomic location. The landmarks used to locate and identify the main trunk of the facial nerve are: (1) the superior surface of the posterior belly of the digastric muscle; (2) the tip of the mastoid process; and (3) the anteroinferior surface of the cartilaginous external auditory canal (Fig. 9.5). An additional point of orientation is the tympanomastoid suture line, which is palpable and approxi­mately superficial to the stylomastoid foramen. The “tragal pointer” is less useful, as it is both distant from the main trunk and cartilaginous and mobile, making its relationship to the nerve less constant. Once these landmarks have been identified, the main trunk of the facial nerve is found at the confluence of these three structures, at the depth of the posterior belly of the digastric muscle. As these structures are identified, very delicate and meticulous dissection is performed through the parotid tissue to prevent any inadvertent injury to the facial nerve. Thin layers of tissue are divided with the bipolar cautery device. As dissection proceeds, it is helpful to mobilize the parotid gland anteriorly on as broad a front as possible, resisting the temptation to dissect only in the anticipated location of the facial nerve. Mobilizing the parotid gland in this manner maximizes exposure of the main trunk once it is identified. In nearly all cases, a branch of the posterior auricular artery is located just superficial to the main trunk of the facial nerve. This branch should be diligently looked for, isolated, and divided. This vessel provides a good lead to the facial nerve, which is invariably located 2–3 mm deeper. At this point, further dissection of the peripheral branches of the facial nerve proceeds in a systematic manner, with the use of a fine clamp for dissection and separation of the parotid tissue; bipolar cautery for hemostasis; and sharp division of the parotid tissue with a scalpel or scissors, keeping the underlying facial nerve under constant vision.

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Fig. 9.5: Landmarks helpful in identifying the main trunk of the facial nerve during parotidectomy.

PAROTIDECTOMY AND EXCISION OF DEEP LOBE PAROTID TUMOR Excision of a tumor confined to the deep lobe of the parotid gland usually amounts to local excision or enucleation of the tumor while keeping its pseudocapsule intact. Regardless of whether a superficial parotidectomy is performed, the deep lobe tumor is generally excised separately, with blunt and sharp dissection and judicious digital dissection to remove the intact tumor in a monobloc fashion. In these cases, removal of all parotid glandular tissue deep to the facial nerve is not necessary and, in fact, poses significant risk to the nerve branches. Classically, it was recommended to first perform a superficial parotidectomy before excising a deep lobe tumor. The rationale for doing so was to maximize the safety of the facial nerve during and after excision of the deep lobe tumor. However, as long as the integrity of the facial nerve is preserved, the need to perform a formal superficial parotidectomy is questionable. In fact, preservation of the superficial lobe of the parotid gland will minimize the esthetic deformity resulting from the soft tissue deficit in the preauricular region. Thus, when possible, we generally prefer to avoid performing a formal superficial parotidectomy in patients with a well-encapsulated tumor confined to the deep lobe of the parotid gland. We have, however, found that preservation of the superficial lobe of the parotid gland does come at a cost: a higher incidence of first bite syndrome. First bite syndrome is the feeling of sharp lancinating pain in the parotid region upon the first bite of a meal, diminishing with subsequent bites. This syndrome is attributable to postsurgical interruption of sympathetic

Salivary Glands

innervation to the gland, resulting in unopposed, simultaneous parasympathetic stimulation of myoepithelial cells. Patients undergoing super­ficial parotidectomy have little or no remaining parotid tissue, and therefore have a much lower incidence of first bite syndrome: approximately 5–10%, compared with 30–40%. The operative procedure for a deep lobe parotid tumor begins with either the usual parotid incision in a preauricular skin crease or a tragal incision. In general, excision of a deep lobe parotid tumor requires minimal elevation of the preauricular skin but does require extension of the skin incision further anteroinferiorly along an upper neck skin crease to allow access to the retromandibular portion of the deep parotid space. After elevation of the skin flap, dissection of the superficial lobe of the parotid gland, to identify the main trunk of the facial nerve, proceeds in the usual fashion. The main trunk of the facial nerve is identified as described above. Further dissection proceeds in the usual fashion, to expose the lower division of the facial nerve and its lowest branch, the cervical branch. The dissection of the cervical branch continues peripherally until its exit from the anterior border of the superficial lobe of the parotid gland. At this juncture, the lower division and its lowest branch have been dissected and can be safely maintained in view. There is no need for further dissection of the superficial lobe of the parotid gland at this point. However, during the remainder of the surgical procedure, the main trunk, the lower division, and the cervical branch are all constantly kept in view to maintain anatomic and functional integrity. Dissection now begins in the deep parotid space cephalad to the superior border of the posterior belly of the digastric muscle. The stylohyoid muscle and the distal external carotid artery both traverse this area, running super­ficial to the deep lobe parotid tumor, and, therefore, usually need to be divided and ligated. In some patients, the styloid process is long and may have to be amputated to facilitate digital dissection and mobilization of the tumor to avoid rupture. The muscles attached to the styloid process are detached with an electrocautery device, and the bony styloid process is denuded. A rongeur is used to amputate the styloid process near its base. The sharp edges at its divided stump are smoothed out. Dissection now begins digitally around the deep lobe parotid tumor in the parapharyngeal space, delicately and carefully, to avoid rupture of the tumor or unnecessary bleeding. Once the tumor is mobilized circumferentially with digital maneuvers, it is delivered from the parapharyngeal space through the stylohyoid window. This is a tight anatomic space between the posterior border of the ascending ramus of the mandible and the greater cornu of the hyoid bone. The tumor should be delivered intact in a monobloc fashion (Figs 9.6A and B). Rupture and spillage of certain tumors, such as pleomorphic adenomas, may increase the risk of recurrence.

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A

B Figs 9.6A and B: (A) Identification and dissection of lower division of facial nerve branches for exposure of a deep lobe parotid tumor; (B) followed by monobloc delivery with careful digital dissection.

Sacrifice of the Facial Nerve With rare exceptions, if the facial nerve is functioning preoperatively, every attempt is made to preserve it, regardless of tumor extent and tumor histologic profile, even in the case of proven malignancy. However, gross tumor should not be left on the nerve; the goal of surgery is to leave no tumor or

Salivary Glands

only microscopic disease behind on the functioning nerve. In these cases, adjuvant radiation therapy is generally mandated. In some cases, the nerve is encased with tumor or is not functioning preoperatively. In these cases, both the proximal and the distal nerve margins should be evaluated by use of frozen section, to assess the feasibility of a nerve graft.

Management of the Eye in Facial Paralysis If the upper division of the nerve is to be sacrificed, and if this can be anticipated at the time of surgery, we will generally plan to also include procedures to aid with eye closure. If not performed in the same setting, these procedures will be performed in the early postoperative period. In most cases, a gold weight is inserted into the upper eyelid, together with the performance of a lower-lid-shortening procedure, such as a lateral tarsal strip. It is important to address both the upper and the lower eyelids, as the lower lid will develop a paralytic ectropion, leading to impaired coverage of the globe and epiphora, owing to the lack of a platform for tears. The gold weight should be measured with dummy weights preoperatively. If this is not possible, a 1.0 gram weight is appropriate for most women, and a 1.2 gram weight is appropriate for most men. The upper eyelid incision should ideally be marked, with the patient sitting upright, in a natural upper eyelid crease, taking care to mark the medial limbus of the eye, which may not be located intraoperatively if a corneal shield is in place. The incision is carried through the orbicularis oculi muscle, with care taken not to disrupt the levator aponeurosis deep to the orbicularis. A suborbicularis plane is then developed over the tarsal plate, down to within 1 mm of the eyelid’s lower margin. The gold weight is centered over the medial limbus of the eye with fine absorbable suture, and the incision is closed. The lateral tarsal strip requires a lateral canthotomy incision, again in a natural skin crease, followed by division of the inferior canthal tendon right at its lateral insertion onto the periosteum. The lateral tarsal tendon is then dissected for 2–5 mm, depending on how much laxity the lower eyelid exhibits. Skin, muscle and conjunctiva are then trimmed from the tarsal plate. This is then sutured to periosteum of the lateral orbital rim, slightly superior to the insertion of the superior canthal tendon, using a fine double-armed permanent suture.

EXCISION OF THE SUBMANDIBULAR GLAND FOR SIALOLITHIASIS Resection of the submandibular salivary gland for neoplasms is a relatively straightforward operation in which Wharton’s duct is ligated near the lateral border of the mylohyoid muscle. In general, Wharton’s duct is not excised

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in toto for neoplasms of the submandibular salivary gland. On the other hand, for patients with obstructive sialadenitis and calculous disease, the entire submandibular salivary gland as well as its extensions and the collecting ducts, including Wharton’s duct, up to its opening at its papilla in the floor of the mouth, should be excised to best prevent development of recurrent stones in the duct remnant. This procedure requires bimanual through-andthrough resection of the entire course of Wharton’s duct from the anterior floor of the mouth, through the intermuscular plane in the floor of the mouth, into the submandibular salivary gland. The operative procedure is conducted using an upper neck skin crease, in the usual fashion, elevating the upper skin-platysma flap and paying careful attention to identifying and preserving the marginal mandibular branch of the facial nerve, which is dissected off the capsule of the submandibular gland and reflected cephalad with the upper skin flap (see Chapter 7). When there is no suspicion of malignancy, it is possible to incise the fascia of the submandibular gland low on the gland and to elevate this superiorly, to protect the nerve. The facial artery and vein are divided and ligated in the usual fashion. The external/cervical component of the operation requires complete mobilization of the submandibular salivary gland up to and deep to the lateral border of the mylohyoid muscle. At this point, a circumferential incision is made in the mucosa of the floor of the mouth, around the opening of the papilla of Wharton’s duct on the ipsilateral side, carefully avoiding any injury to the papilla of the contralateral Wharton’s duct. This incision is extended up to 1 cm posteriorly in the lateral floor of the mouth. Circumferential mobilization of Wharton’s duct is now performed, carefully separating it from the lingual nerve and the lingual artery and vein, securing absolute hemostasis. Once the duct is mobilized, a 2-0 silk suture is used to tie the distal stump of the duct, and long ends of the silk suture are left for identification of the distal end. Once mobilization of Wharton’s duct through the floor of the mouth up to the mylohyoid muscle is completed intraorally, attention is focused back to the cervical wound, where further distal mobilization of Wharton’s duct deep to the mylohyoid muscle is performed, until the entire duct is completely mobilized, permitting removal of the duct in its entirety. This maneuver ensures that the entire inflamed salivary gland and salivary collecting duct system is resected, to avoid formation of recurrent stones in the salivary duct system. The intraoral wound is closed, in the usual watertight fashion, with interrupted chromic catgut sutures, and the neck wound is closed in layers. A small Penrose drain is used for drainage of the dead space, and the drain is brought out through the posterior end of the incision.

Chapter

Other Tumors

10

CAROTID BODY TUMORS AND PARAGANGLIOMAS Resection of carotid body tumors and other paragangliomas, such as those arising from the vagus nerve or the sympathetic chain, require meticulous attention to detail to minimize hemorrhage and to avoid injury to other cranial nerves during surgical resection. In general, despite their intense vascularity, these tumors do not have a single solitary feeding vessel, since most of the blood supply comes from the vasa vasorum of the adventitia of the carotid artery. Therefore, we have not found that routine preoperative embolization of these tumors minimizes bleeding. In fact, the embolic material causes inflammation in the tumor tissue and makes the dissection more difficult. Therefore, we do not recommend routine embolization for paragangliomas in the head and neck. The main requirement for safe conduct of these operations is excellent cross-sectional imaging, to demonstrate the anatomic dimensions of the tumor as well as its location and relationship to major vessels and other cranial nerves. This is best accomplished with a contrast-enhanced CT scan and/or a contrast-enhanced MRI (Fig. 10.1). For instrumentation, a bipolar electrocautery device with fine tips is the sine qua non for the safe conduct of this operation. Similarly, appropriate dissecting instruments must be available. These include a blunt Penfield dissector (Penfield #4, normally used for elevation of the dura), a Freer elevator, a fine-tipped tenotomy scissor, a fine Adson clamp, and micro hemostats (Figs 10.2 and 10.3). Before the start of the operative procedure, Fogarty catheters, vascular clamps and vascular shunts should be available in the OR. Similarly, if the surgeon doing the procedure is not comfortable with vascular repair of an inadvertent injury to the vessel, a vascular surgeon should be available on standby. The patients must be maintained at a relatively low systolic pressure of approximately 90 mm Hg. An upper neck skin crease is used to place a transverse incision, and the skin flaps are elevated in the usual fashion. To maximally expose the carotid sheath and the tumor, the first step is to remove

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Fig. 10.1: Postcontrast T1 weighted MRI, showing Shamblin type II (Right) and type III (Left) carotid body tumors.

Fig. 10.2: Instruments used in dissection of carotid body tumors. From left to right, a Penfield #4 dissector, Freer elevator, fine Adson hemostat, fine-tipped tenotomy scissor, and micro-mosquito hemostat.

Other Tumors

Fig. 10.3: Detail of the dissecting tips of the Freer elevator (top) and the Penfield #4 dissector (bottom).

Fig. 10.4: Exposure of the carotid sheath first requires excision of level II and III lymph nodes.

lymph node-bearing tissue from levels II and III (Fig. 10.4). It is quite common to observe hypervascularity of the adventitia of the carotid artery proximal to the tumor, over the common carotid artery, or of the involved vagus nerve or sympathetic chain. This increased vascularity results from the dilated,

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tortuous, premature blood vessels in the adventitia of the artery. However, these fine immature vessels can be easily controlled with bipolar cautery. The common carotid artery is circumferentially mobilized, and a vessel loop is passed around it for control of accidental hemorrhage from the distal part of the carotid system. Dissection proceeds in a subadventitial plane proximal to the tumor, through the adventitia of the common carotid artery. The usual mode of dissection is to use the bipolar cautery device first, up to a segment of 3–4 mm of adventitia, which is then elevated with either a Penfield elevator or a micro hemostat and separated from the tunica media of the carotid artery and sharply divided with tenotomy scissors. Dissection for carotid body tumors thus proceeds meticulously and slowly along the external and internal carotid branches distal to the carotid bulb. A Freer elevator is used to dissect the tumor off the external and internal carotid arteries, parti­ cularly in patients with a Shamblin type II tumor. When this technique of bipolar cautery is used for the adventitial vessels, subadventitial dissection and sharp division allow excellent mobilization and delivery of the carotid vessels off the tumor or from the tumor, to facilitate a safe and complete tumor excision. This technique is used even for Shamblin type III tumors. The tumor is split in the region where it is thinnest over the carotid artery, maintaining complete hemostasis, and the carotid artery is delivered from the tumor intact, allowing excision of the tumor. Rarely ever does one need to resect the carotid artery and use a vascular graft to replace the vessel.

Chapter Transoral Surgery and Endoscopic Techniques

11

TRANSORAL LASER MICROSURGERY AND TRANSORAL ROBOTIC SURGERY Advances in technology have facilitated minimally invasive transoral approaches to the larynx, hypopharynx and oropharynx. Transoral laser microsurgery (TLM) and transoral robotic surgery (TORS) use different instrumentation, but both offer the ability to resect tumors of the laryngopharynx without an external approach, such as mandibulotomy or laryngofissure. Decision-making regarding indications and candidacy for these procedures is beyond the scope of this text, and readers are referred to the published reports of groups experienced with transoral laser and robotic surgery.

Choosing an Approach The decision of whether to use the robot or the operating microscope and laser depends on the surgeon’s personal preference, with the exception of cases of tumors of the glottic larynx, which cannot currently be approached via TORS. There are other critical differences. TLM lends itself better to systematic, piecemeal tumor resection, whereas TORS is generally better suited to monobloc resection of the tumor. TORS permits operating with a 30° endoscope, whereas TLM is a line-of-sight procedure. TORS is performed with a bedside assistant for retraction and suctioning, whereas TLM is performed with the surgeon at the head of the bed. These factors may have implications for which technique is better suited to a particular tumor.

Evaluating Candidacy for Transoral Exposure However, for both TLM and TORS, a critical determinant of candidacy for surgery is the patient’s anatomy. The key factors that strongly determine the amount of access the surgeon can obtain with a laryngoscope (or laryngopharyngoscope), delineated by the Washington University TLM group as “the 8 Ts”, are:

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1. 2. 3. 4. 5. 6. 7. 8.

Teeth: The presence of upper incisors and the degree of overjet, which affect the extension of the laryngoscope Trismus: Significant trismus will limit exposure Tongue: The volume of the base of the tongue will affect exposure of base of tongue and laryngeal tumors Tilt: Atlanto-occipital extension is necessary for adequate laryngeal exposure Transverse dimensions of the mandible: A narrow mandibular arch will limit exposure and ability to displace the tongue Torus: Mandibular tori will limit mobility of the laryngoscope Treatment: Radiation therapy-induced fibrosis will limit exposure Tumor: An exophytic tumor may require debulking in order to clearly expose the complete base of the tumor and its extent of mucosal involvement

Safety, Setup and Exposure Close communication with the anesthesiologist is critical for safe and expeditious transoral surgery. Both TORS and TLM are performed best with the bed turned 180° from the anesthesiologist, to accommodate the necessary instrumentation. This underscores the need for both the surgeon and the anesthesiologist to “share” the airway. Live video of the operative procedure should be televised in the room so that the assistants and anesthesiologist can follow the progress of the procedure and anticipate needs as they arise. Airway fires during transoral laser surgery are catastrophic and should never occur. For TLM cases, we recommend performing an additional preoperative timeout or pause specifically for laser safety before starting surgery. During this time, members of the operative team and OR staff verify that it is safe to proceed with laser surgery. This will generally involve ensuring that all OR staff have protective glasses, that the patient’s face and nearby anesthesia tubing are completely covered with moistened towels, and that a lasersafe endotracheal tube, if available, has been used. The fraction of inspired oxygen (FIO2) delivered with anesthesia should ideally be kept under 27% at all times; below this level, the risk of airway fire is extremely low. This may necessitate tolerating a patient blood oxygen saturation slightly lower than 100%. Nitrous oxide should be avoided. Before starting, a selection of laryngoscopes, laryngopharyngoscopes and transoral retractors should be available in the OR, as it cannot always be predicted which instrument will provide optimal exposure. At a minimum, we recommend a selection of laser laryngoscopes, the FK (Feyh-Kastenbauer) laryngopharyngoscope (Fig. 11.1), bivalve supraglottiscope (Fig. 11.2), and a standard Crowe-Davis tonsillectomy retractor. These instruments will provide access to the tonsil, base of tongue, and supraglottic and glottic larynx.

Transoral Surgery and Endoscopic Techniques

Fig. 11.1: The F-K (Feyh-Kastenbauer) laryngopharyngoscope.

Fig. 11.2: The bivalve supraglottiscope.

The Göttingen suspension arm provides a mobile base attached to the bed and keeps the scope suspension arm off the patient’s chest (Fig. 11.3). Obtaining ideal exposure may require sequentially inserting a series of different laryngoscopes or using a variety of different tongue-retracting

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Fig. 11.3: Suspension using the Göttingen suspension arm.

blades, but this time investment is worthwhile as it creates exposure for tumor resection and minimizes the number of times the scope or retractor will need to be repositioned during the case. Complete paralysis is mandatory for effective exposure. The head will be extended at the atlanto-occipital joint. For larynx exposure, flexing the neck often provides better exposure; for base of tongue exposure, extending the neck is generally better. Again, it is critical to spend time optimizing exposure before beginning the resection. Setup of instruments can also be optimized for expeditious surgery. For TLM cases, where the surgeon sits at the head of the bed, it is important to avoid “pedal confusion”. For this reason, we advise separating the pedals corresponding to the laser, the bipolar cautery device, and the suction cautery device and delegating the cautery pedals to one assistant each (Fig. 11.4). Before starting surgery, it is important to make sure that two suction lines are functioning, that endoscopic clip appliers of various sizes (5 mm most commonly) are available for use, and that the cautery devices (suction cautery and endoscopic bipolar cautery) are ready for use. In lieu of endoscopic bipolar cautery, a standard monopolar cautery device can be touched to small insulated alligator forceps, which are used to grasp small vessels. A smoke evacuator is required to keep the field clear; it can be attached to the scope or to a red rubber catheter that is passed through the nose and situated in the pharynx. A larger (laparoscopic) clip applier should be available in the room at all times, although not necessarily opened on the sterile field, for the uncommon

Transoral Surgery and Endoscopic Techniques

Fig. 11.4: Delegation of different instrument pedals to assistants is critical to avoid “pedal confusion” during transoral surgery.

situations in which a large bleeding vessel cannot be adequately controlled with the standard endoscopic clips. For TORS cases, the FK laryngopharyngoscope is the preferred means of exposure, although a Crowe-Davis tonsillectomy rectractor will also work well for tonsil tumors. The bedside assistant is a critical and often underappreciated member of the surgical team, as a provider of retraction and suctioning and for applying a bipolar cautery device or clips. To maximize visibility and to avoid collisions with the robotic arms, the bedside assistant should work off the video screen and resist the temptation to work by looking into the mouth (Fig. 11.5). As in all laser cases, a sitting stool with adjustable armrests is needed to provide a stable base for the arms and to avoid strain and tremor (Fig. 11.6). Depending on surgeon preference and on availability, the free beam CO2 laser and the hollow-core CO2 laser fiber are both options for the delivery of laser energy for TLM surgery. TORS surgery generally relies on monopolar cautery, although laser attachments are available for both CO2 and thulium lasers.

Piecemeal Resection with Margin Mapping In TLM surgery, only very small tumors are removed en bloc (Fig. 11.7A). The majority of space-occupying tumors of the larynx and oropharynx are removed in a deliberate piecemeal fashion. This permits assessment of

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A

B Figs 11.5A and B: Participation of a bedside assistant during transoral robotic surgery.

depth at multiple sites along the tumor and reduces the chance of an unintentionally positive deep margin (Fig. 11.7B). To expose the base of the tumor, it may be necessary to initially debulk tumors that are large and bulky (Fig. 11.7C). Accordingly, in most cases, the initial laser cut is made directly through the midportion of the tumor and carried down to the depth of the tumor (Fig. 11.8). The interface between tumor and normal tissue is easily

Transoral Surgery and Endoscopic Techniques

Fig. 11.6: A surgical chair with adjustable armrests is critical for transoral laser microsurgery.

B

A

C Figs 11.7A to C: Tumor cuts in transoral laser microsurgery. (A) Very small tumors can be removed en bloc with incisions made widely around the tumor; (B) Most tumors should be removed in a multibloc fashion, with transtumoral incisions used to ascertain depth; (C) Large tumors may need to be initially debulked, then removed in a multibloc fashion.

appreciated, as the tumor will be charred by laser energy, in contrast to normal tissue. In all cases, it is critical that the surgeon personally ink the specimen, to clarify orientation and to define which margins are actually deliberate cuts through the tumor. To most accurately maintain orientation of the

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Fig. 11.8: Initial transtumoral laser cut through the midpoint of an oropharyngeal tumor.

Fig. 11.9: Immediate mounting of the endoscopically removed specimen to preserve orientation.

tumor, the tumor should be immediately mounted in place (Fig. 11.9) and the orientation of margins should immediately be marked with ink or pins as soon as the tumor has been removed from the patient (Fig. 11.10).

Transoral Surgery and Endoscopic Techniques

Fig. 11.10: Immediate labeling of margin orientation with pins or ink in the operating room.

Transoral Supraglottic Laryngectomy Many supraglottic tumors can be approached via TLM or TORS, although TLM offers superior exposure in some cases. If TLM is chosen, the best access to supraglottic tumors is generally afforded by the bivalve laryngoscope. These are available with side panels to prevent prolapse of the tongue into the lumen of the scope; alternatively, a latex glove finger wrapped around the scope can be used for this purpose (Fig. 11.11). The patient is ideally intubated with a small (size 5.0 or 5.5) endotracheal tube, and the bivalve scope is positioned, with the tip lifting up the hyoid bone. A long piece of tape with gauze can be used to apply downward pressure on the laryngeal framework, or an assistant can provide pressure. To expose the invasive base of a large, exophytic tumor, superficial debulking may be necessary. In these cases, it is most helpful to leave a large remnant of tumor, which is readily identifiable and easily retracted. The initial cut for supraglottic resection is a midline cut through the epiglottis, which is helpful in orienting the surgeon to the pre-epiglottic space. As dissection continues through the depth of the tumor, the vocal cord spreader instrument provides (Fig. 11.12) useful outward distraction of the tumor and helps to visualize the depth of resection. Additional dissection through the pre-epiglottic space, along the inner perichondrium of the thyroid cartilage, then follows. As dissection proceeds laterally, the superior laryngeal artery should be anticipated. It will be encountered within the “trifold” region, which is the

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Fig. 11.11: Use of a latex glove finger to avoid tongue prolapsed between the blades of the bivalve laryngoscope.

Fig. 11.12: The vocal cord spreader is a useful instrument to distract tissue laterally when making a transtumoral cut through a large tumor.

confluence of the lateral edge of the epiglottis, the aryepiglottic fold, and the pharyngoepiglottic fold. The artery will be encountered just beyond the superior laryngeal nerve. Once the nerve is encountered, dissection should be deliberately slow in this region; once the vessels are identified, they should be repeatedly clipped with endoscopic clips and then divided.

Transoral Surgery and Endoscopic Techniques

If significant bleeding is encountered at the time of tumor resection, it should be controlled in the standard fashion, and the superior laryngeal artery should be ligated proximally at the time of neck dissection (if a neck dissection is being performed in the same operative setting).

Transoral Surgery for Glottic Tumors Glottic tumors are much more accessible via TLM approaches than TORS. Small tumors of the vocal cord can be readily excised en bloc, but larger tumors should be excised in a piecemeal fashion. Care should be taken to optimize exposure before commencing resection. The false vocal cord can be resected first, if necessary, to enhance exposure. Following this, the initial tumor cut should be posterior, at the level of the endotracheal tube. Any additional tumor posterior to this cut should be removed last, after repositioning the tube by displacing it anteriorly. Tumors involving both vocal cords will necessitate a split at the anterior commissure. When this is performed, it is advisable to leave a remnant at the anterior commissure that is retractable.

Transoral Surgery for Base of Tongue Tumors The FK laryngopharyngoscope or short bivalve laryngoscope provides optimal access to base of tongue tumors, for either TLM or TORS (Fig. 11.13). The FK retractor provides excellent exposure and working space for either handheld laser fibers or robotic arms (Fig. 11.14). The critical aspect of base of tongue resection is successful identification and management of the dorsal branches of the lingual artery. These branches should be anticipated to enter the surgical field laterally; they continue to run medial to the hyoglossus muscle. It can be helpful to scrutinize the preoperative CT scans to map out these branches, as well as to pause during resection to look for pulsations in the tongue base, especially when working laterally. Clip appliers should be available from the start of surgery. As mentioned above, in the case of significant hemorrhage from one of these branches, the corresponding artery (lingual or facial artery) should be ligated proximally in the neck at the time of neck dissection.

Transoral Surgery for Tonsil Tumors Similar principles to those used in exposure and piecemeal resection apply here. For the smoke evacuator, inserting a large red rubber catheter transnasally is more effective than attaching the smoke evacuator to the retractor. As with base of tongue surgery, endoscopic clip appliers should be available from the start of the case. In TORS operations in which en bloc resection is planned, the constrictor muscle is taken as a deep margin. In TLM operations in which piecemeal

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Fig. 11.13: The FK retractor provides excellent access to base of tongue tumors, for either TLM or TORS resection.

Fig. 11.14: Positioning of robotic arms through the FK retractor.

resection is planned, whether the constrictor muscle is resected is determined on the basis of the depth of tumor invasion. In both cases, the styloglossus and stylopharyngeus muscles will be identified immediately deep to the constrictor musculature. The glossopharyngeal nerve runs in between these two muscles and is generally visible transorally.

Transoral Surgery and Endoscopic Techniques

Transoral Approaches to Squamous Cell Carcinoma of Unknown Primary Origin In patients diagnosed with metastatic squamous cell carcinoma to the neck of unknown primary origin, both TORS and TLM approaches offer enhanced opportunities to diagnose and treat the primary site of tumor, commonly in the oropharynx. Depending on the planned modalities of treatment, this may be combined with a neck dissection if indicated. In these cases, the patient is ideally nasally intubated. The sites of disease in the oropharynx, including the palatine tonsil, glossotonsillar sulcus, and base of tongue, are examined in the standard fashion with palpation and laryngoscopy. The operating microscope is then brought into the field and mucosal areas of the upper aerodigestive tract carefully examined under microscopic vision, searching for telangiectasias, abnormalities in the mucosa, or small palpable masses identified with a smooth suction tip. If any suspicious masses are identified, they can be biopsied and then resected to negative margins using either TLM or TORS techniques. Care should be taken in the glossotonsillar sulcus to identify tonsillar branches of the facial artery and clip these if needed. If no apparent primary tumor is identified, TLM or TORS techniques can be used to excise both the palatine and lingual tonsils. The lingual tonsil excision is carried down to a plane just superficial to tongue muscle, and extended 1 cm past the midline of the tongue base. Pathologic examination of these tissues will commonly identify a small primary tumor.

ENDOSCOPIC MANAGEMENT OF TRACHEAL AND SUBGLOTTIC STENOSIS In adult patients, tracheal stenosis is most definitively treated with tracheal resection and reanastomosis, a safe and straightforward procedure (see Chapter 6). However, in certain highly selected patients, endoscopic management of tracheal stenosis may be effective. These include: • Patients with short-segment (< 1 cm), web-like stenosis • Patients with very recent (fresh) stenosis observed shortly after prolonged intubation • Patients unable to undergo definitive tracheal surgery because of significant comorbidity As with all transoral and airway operations, these procedures depend on a high level of communication between the surgeon and the anesthesiologist. The importance of this is particularly escalated in patients with airway stenosis. Therefore, it is critical to have a detailed discussion regarding the airway management plan before induction of anesthesia. Along the same lines, it is critical to assemble all airway equipment and instruments before the patient is brought into the OR.

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For subglottic and tracheal stenosis, we have found suspension laryngoscopy with jet ventilation to provide ideal exposure and access to the trachea. This procedure generally requires the following instrumentation: • A rigid (e.g. Dedo) laryngoscope • Lewy suspension system • Jet ventilation setup (such as a Hunsaker catheter) • 0° and 30° Hopkins rod telescopes • Flexible bronchoscope • Balloon dilator (esophageal balloons are preferred to tracheal balloons) The following equipment may not always be necessary but should be immediately available: • A selection of small (size 4.5, 5.0, 5.5, 6.0) endotracheal tubes • Rigid bronchoscope with jet ventilation catheter attached • Tracheotomy set, opened and ready to use • CO2 laser (micromanipulator on a microscope or handheld fiber) • Chest tube tray (in the event of tension pneumothorax) There are a multitude of approaches to the anesthetic and airway plan. In the standard patient with subglottic or tracheal stenosis, we tend to follow this sequence of events for establishment of the airway and initial exposure: 1. The patient is brought into the room; IV access is secured. The tracheotomy set is opened, a Bovie grounding pad is placed, and suction tubing is set up in case there is a need to perform an urgent surgical airway at any point. 2. The patient is preoxygenated, and general anesthesia is induced with a short-acting paralytic. 3. The anesthesiologist verifies that the patient can be easily mask ventilated, with satisfactory chest rise. 4. The table is turned 90°. 5. The patient is maximally paralyzed. 6. The Dedo laryngoscope is inserted and suspended, and jet ventilation is connected. 7. The jet ventilation catheter must be kept above the stenosis at all times, to avoid the risk of pneumothorax attributable to incomplete egress of air. If a Hunsaker catheter is used, its tip is placed in the supraglottis. 8. Satisfactory chest rise and fall is confirmed with jet ventilation. 9. If there are concerns about egress of air, a large-gauge angiocath can be placed percutaneously below the stenosis. However, in this scenario, dilation should proceed expeditiously, and a high level of suspicion should be maintained for pneumothorax. If there are difficulties maintaining adequate ventilation, the options are to: • Intubate through the stenosis with a small endotracheal tube. The dilation can still be performed by removing and replacing the tube.

Transoral Surgery and Endoscopic Techniques

•

Expeditiously open the stenosis by inserting a rigid bronchoscope through the stenosis and ventilating through the bronchoscope. • Perform a tracheotomy. Once the airway has been established and the patient is being well ventilated, attention can be turned to the dilation itself. The following steps are followed: 1. Intravenous steroids are administered. 2. The laryngoscope is inserted with the tip of the scope slightly through the true vocal cords. This positions the scope in the subglottis, enhances exposure of the stenotic area, and avoids trauma to the vocal cords by repeated insertion and removal of instruments. The laryngoscope is then suspended. This technique, if performed carefully, does not lead to any injury or edema of the true vocal cords. 3. The stenosis is brought into view by external manipulation of the trachea; it can be carefully examined with the microscope, rigid telescopes or flexible bronchoscope. To carefully examine the character, location, grade and length of the stenosis, it is generally easiest to pass the flexible bronchoscope into the trachea. 4. To minimize the formation of further scar tissue, the stenosis is incised using a mucosal sparing technique. Usually, this requires three or four radial incisions into the stenosis, which are made with the laser (either handheld fiber or free-beam) attached to the microscope. 5. An esophageal dilation balloon of the desired diameter is then inserted through the stenosis, alongside the telescope/bronchoscope or under microscopic vision. Once the patient has been preoxygenated, the balloon is inflated and kept inflated for at least 60 seconds. 6. The result is inspected, and further dilation is performed as indicated (Figs 11.15A to E). 7. A postoperative chest radiograph is obtained to rule out pneumothorax. In the trachea, esophageal dilation balloons (Fig. 11.16) generally function better than tracheal dilation balloons, as the esophageal balloons are longer and less likely to slip during dilation. There is no clear evidence in the literature supporting the use of either mitomycin C or intralesional steroids, and these agents are rarely used. For stenotic regions in the thoracic trachea or bronchi, suspension laryngoscopy may not be strictly necessary, although it does provide optimal and secure ventilation and airway access. Alternate approaches are: • Rigid bronchoscopy with jet ventilation • Laryngeal mask airway with flexible bronchoscopy through the laryngeal mask airway tube.

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A

B Figs 11.15A and B

PERCUTANEOUS ENDOSCOPIC GASTROSTOMY TUBE INSERTION Percutaneous endoscopic gastrostomy (PEG) tube insertion is a useful technique for the head and neck surgeon and is particularly applicable in the management of patients undergoing extensive resection and reconstruction, in whom it is most straightforward to insert the PEG tube at the time of surgery. This avoids the need for instrumentation of the upper

Transoral Surgery and Endoscopic Techniques

C

D Figs 11.15C and D

aerodigestive tract for PEG insertion at a later date. In patients who are not undergoing surgical resection but are undergoing examination and biopsy under general anesthesia, it may be logistically desirable to insert a PEG feeding tube in anticipation of chemoradiation therapy, obviating the need for a second anesthetic. A single dose of antibiotics (commonly, first-generation cephalosporin) is administered. A standard, complete upper gastrointestinal endoscopy is performed. Careful examination of the esophageal mucosa has particular

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E Figs 11.15A to E: Technique for endoscopic management of tracheal stenosis. (A) Preoperative photograph demonstrating high-grade stenosis; (B) Intraoperative photo after radial incisions made in stenotic segment and (C) after balloon dilation; (D) Endoscopic view 1 week and (E) 1 year after dilation Source: Pavan Mallur, MD, Beth Israel Deaconess Medical Center, Boston, USA.

Fig. 11.16: Inflatable balloon dilator used for the dilation of tracheal stenosis.

Transoral Surgery and Endoscopic Techniques

importance for the patient with head and neck squamous cell cancer, who is at elevated risk of second primary cancers of the esophagus. Since the PEG will be used for feeding, gastric outlet and duodenal obstruction should be quickly ruled out by advancing the scope into the duodenum. The stomach is maximally insufflated with air, and the room lights are dimmed. The anterior abdominal wall should be transilluminated with the gastroscope; if needed, the light can be turned up to the “transilluminate” setting. A single finger is then used to indent the anterior abdominal wall at least 1–2 cm away from the costal margin. It is important that the endoscopic view reveal focal indentation of the abdominal wall. In most cases, the PEG tube should not be inserted if excellent transillumination and focal finger indentation cannot both be achieved. The abdominal wall is now sterilely prepared and draped. Before inserting the needle, the endoscopic snare is passed through the gastroscope and positioned. This saves time; once the stomach is punctured, effective insufflation is sometimes difficult to maintain. At the point of PEG insertion, a 5 mL syringe with sterile water is carefully inserted, with suction in the syringe. The presence of air bubbles in the syringe before entry into the stomach may indicate entry into the colon; if this occurs, another site of insertion should be used. Once the angiocath is in the stomach, the snare is maneuvered around the angiocath, to facilitate grasping the guidewire. The feeding tube can then be inserted in the standard pull fashion and secured to the abdominal wall with 1–2 cm of distance left between the external bumper and skin.

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Index Page numbers followed by f refer to figure.

A Abdominal wall 121 Adenoma 84 single 86 Anesthetic injection for local, locations of local 85f Angiosomes of face 14 Anterior abdominal wall 121 craniofacial surgery 35 Anterolateral neck dissection 72 Apron incision 62, 62f Atlanto-occipital extension 104 joint 106 Autologous bone 31

B Balloon dilator 116 of endotracheal tube 68 Bedside assistant transoral robotic surgery 108f Berry’s ligament 80 Bifrontal craniotomy 35 Bilateral comprehensive neck dissections 71f Biopsy excisional 70 incisional 70 Bipolar electrocautery device 99 Bivalve supraglottiscope 105f Bleeding cancellous bone 19 Blood supply to face 14 scalp 14 subsites, major 14 Bone segments during healing 54 Buccinator see Cheek

C Cancellous bone 46 Canine fossa 34

Canthal tendon, superior 97 Canthotomy incision, lateral 97 Carotid artery, adventitia of 101 Carotid body tumors 99 dissection of 100f resection of 99 Cautery injury 83 Central compartment lymph node dissection 76f node dissection 76 palatal defect, repair of 33, 58 Cephalocaudad 66 Cervical esophagus 60 incision 78 spine deformities see Trismus thymectomy 87 Cheek 45 Chemoradiation therapy 65 anticipation of 119 Chyle leak, avoidance of 75 Circummandibular retention sutures 52f Closure after wedge excision of auricle 24f Comprehensive neck dissections 72 Contemporary operating room 2f Contralateral arm 4 nerve 83 Cricothyroid joint 82 membrane 78 Crowe-Davis tonsillectomy rectractor 104, 107 Crucial in surgical procedure 11 Cutaneous nerves 74

D Debulk tumors 108 Deep lobe parotid tumor 96f excision of 94 Dental obturator 32, 58

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Diffenbach 26 Digastric muscle 67, 90, 92, 95 Dissection technique, basic 12 Double adenoma 86 Double rotation scalp flap, design of 19f Dry sebaceous material 17f

E Electrocautery tip extensions 7 Electrodissection instruments 6 Electrosurgical instruments 6f Endonasal skull base surgery 36 Endoscopic intracranial surgery 36 management of tracheal 115 techniques 103 Endotracheal tube 28 Epiglottis, lateral edge of 112 Erb’s point, muscle 90 Esophageal mucosa 119 Eye in facial paralysis, management of 97 Eyebrow 28

F Facial expression, muscle of 14 incision 26 nerve 95, 96 during parotidectomy, main trunk of 94f sacrifice of 96 skin flaps, types of 25 lesions, excision and primary closure of 23 Feyh-Kastenbauer laryngopharyngo scope see F-K laryngopharyngo scope Fibula graft to segmental mandibulec tomy defect 48f FIO2 see Inspired oxygen, fraction of Fish hook excellent retraction of skin flaps 12f retractors 79 F-K laryngopharyngoscope 105f, 107 FK retractor excellent access to base of tongue tumors 114f Flat tip bovie 10f

Four-gland exploration 86 hyperplasia see Double adenoma Frontal craniotomy 35

G Galeal relaxing incisions 20f Gingivolabial sulcus 53 Gland, superior 87 Glottic tumor 59 Göttingen suspension arm 105 suspension 106f Great auricular nerve, management of 90

H H incision 62 Handheld carbon dioxide laser scalpel 8 Harbor multigland disease 86 Hard palate, preservation of 34 Harmonic scalpel 8 Healing of tracheostome 62 Hemimaxillectomy 29 Hunsaker catheter 116 Hyoid bone 80 cuts, location of 67f Hyperkeratosis see Leukoplakia Hypopharynx 59

I Incise platysma 10f Inferior alveolar 14 Inferior thyroid artery 80 Infiltration before incision 15 Inflatable balloon dilator for dilation of tracheal stenosis 120f Infraorbital alveolar 14 skin crease 27f, 38f Infratemporal fossa 31, 37 Initial transtumoral laser 110f Inspired oxygen, fraction of 104 Intralesional steroids 117 Intraoral lesions 47

J Jugular node 72

Index

K Keratinizing mucosa 42

L Labial branches of facial artery 14 Langer’s lines 8 Large retrosternal goiters 78 Laryngeal nerve 80 superior 112 squamous cell cancer 75 tumors, advanced 60 Laryngectomy, incisions for 61f–64f Larynx 59 Lateral neck dissection 71f Lateral neck dissection See Jugular node Leukoplakia 45 Ligasure cautery device 7 Lip, excision of 42 Lip-splitting incision 55 Lower division of facial nerve branches, dissection of 96f Lower part of maxilla, resection of 29 Low-stage tumors 59 Lymph node biopsy 69 Lynch 26 extension see Eyebrow

M Mandible, management of 46, 48 Mandibulectomy 46 bone 50f, 51f marginal 48 segmental 47f Mandibulotomy 52 lateral 52 Marginal mandibular branch of facial nerve identification of 73f preservation of 72 mandibulectomy 48 Maxillary antrum 34 swing approach 38–40f Maxillectomy defect 31 management of 31 Merkel cell carcinoma 69 Midcervical skin crease 71 Middle cranial fossa 37, 41

Midline mandibulotomy 52 vertical incision 61, 61f Minimally invasive parathyroidec tomy 84 Monobloc delivery with careful digital dissection 96f Mouth 45 Mucocutaneous junction 43f Mucoperiosteal incision 38f Mucosal edges closer 44 Myelohyoid see Mouth sling 54 muscle 98 Myoepithelial cells 95

N Nasal cavity 26 intubation 28 subunits 27f, 38f Nasolabial orbital region 26 skin crease 28 Neck 69 dissection 70, 71 extent of 71 in postchemoradiation salvage setting 75 incision 70, 71f lateral 81 selective 72 squamous cell cancer 121 Needle tip bovie 10f Nerve monitoring 83 Nonthyroid diagnoses 78 Nose 26 Nuclear medicine 84

O Oculi muscle, orbicularis 28 Ohngren’s line 29 Open head and neck surgery 9f Operating room setup 1 Oral cavity 42, 70 partial glossectomy 42 Oropharyngeal tumor 110f Osteotomies preserving angle of mandible 47f

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P Palatal fenestration 32 for hard palate tumors 57 island flap for reconstruction of hard palate defect 33f osteotomy 37, 38f Paragangliomas 99 Paramedian mandibulotomy 53 design of 54f Paranasal sinuses 26 Parathyroid gland 78, 84 superior 80 surgery 84 Parathyroidectomy, subtotal 86 Parotid gland 95 initial dissection of 92 Parotidectomy 94 neck 71f Partial maxillectomy 29 Pectoralis major myocutaneous flap 62 Penfield dissector 99 Percutaneous endoscopic gastrostomy 118 tube insertion 118 Pericranium level of 19 preservation of 18f Perivascular lymph nodes 73 Pharyngeal closure 64 reservoir 61 squamous cell cancer see Laryngeal squamous cell cancer Pharyngolaryngectomy see Total laryn gectomy Philtrum of upper lip 28 Phrenic nerve 75 Piecemeal resection with margin mapping 107 Pinna, primary closure of 23 Platysma 79 Pleomorphic adenomas 95 Positron emission tomography 60 Postcontrast T1 weighted MRI 100f Posterolateral neck dissection 72 Postmaxillectomy defect, management of 31

Preauricular region 88 skin 88, 95 Premature blood vessels 102 Pretragal skin 89 Primary closure of facial skin lesions 23 Proximal trachea 66 Pterygoid plates 31 Ptotic submandibular gland 72

R Ramus, ascending 47 Rapid parathyroid hormone 81 Regional anesthesia for minimally invasive parathyroidectomy 85f Relaxed skin tension lines guide of skin incisions 9f, 15f Rhinotomy incision notch in nasal sill, lateral 27f Robotic arms FK retractor 114f Rotation of flaps 19f

S Salivary glands 88 Scalp after wide excision 19f excision 18f with beveled incisions, depiction of 17f incisions, surgery of 15 primary closure versus skin graft versus rotation flap, surgery of 16 surgery of 15 Segmental mandibulectomy 46 Serum calcium level 81 Shah angled bipolar cautery forceps 7f bipolar forceps 7 Shiny skin-on-bone 18f Skin flaps, elevation of 8, 90 graft 23 in oral cavity 45 on scalp 18f fixation of 21 method of 21 incision 8 of face, scalp 14

Index

platysmal flaps 8 sensation, preservation of 74 Skull base surgery 35 Small tumors of mucosa 57 Soft palate, preservation of 30 Specific surgical procedures 3 Sterile drape for head and neck surgery 4f Sternocleidomastoid muscle 84, 92 Sternohyoid muscles 80, 81 Sternomastoid muscles 80–82, 92 Straight bipolar forceps 7 Styloglossus muscle 114 Stylohyoid muscle 90, 95 Stylopharyngeus muscle 114 Subciliary 26 incision 38f Subgaleal hematoma, potential for 22 Subglottic stenosis 115, 116 Submandibular gland fascia 73 for sialolithiasis, excision of 97 salivary gland 98 Submental skin laxity 56f Suborbicularis plane 97 Subplatysmal flaps 84 Suction drains, placement of 77 Superficial parotidectomy 88, 94 incision 88 temporal artery distribution 14 Superior skin-platysma flap, elevation of 73f Superselective nodal dissection 75 Supraclavicular fossa 71 Supracricoid partial laryngectomy 59 Supraglottic partial laryngectomy 59 tumor 59 Supraomohyoid neck dissection 72 Supraorbital arteries 14 Supratrochlear arteries 14 Surgical instrumentation, basic 5 principles, basic 1 techniques, basic 8 Symphysis and parasymphyseal region 46

T Teeth 104 Tertiary hyperparathyroidism 87 Thyroid cancer 82 gland 7, 78 lobectomy 78 tumors and retrosternal goiters, surgery for large 81 vein, superior 80 Thyroidectomy 71f, 79f and bilateral neck dissections 71f and neck dissection 81 incision for 79f TLM see Transoral laser microsurgery TM joint 46 Tongue 104 prolapsed between blades of bivalve laryngoscope 112f resection, oriented 43f TORS see Transoral robotic surgery Torus 104 Total laryngectomy 61 thyroidectomy 80 thyroidectomy see Thyroid lobectomy Trachea 59 Tracheal resection 66 stenosis see Subglottic stenosis stenosis, endoscopic management of 120f Tracheoesophageal plane 66 puncture 65 Tragal cartilage 88 incision 88 for parotidectomy 89 pointer 93 Transconjunctival 26 Transoral exposure, evaluating candidacy for 103 laser microsurgery 5f, 103 critical for 109f robotic surgery 103

127

128

Technical Variations and Refinements in Head and Neck Surgery

supraglottic laryngectomy 111 surgery 103 for tongue tumors 113 for tonsil tumors 113 Transverse dimensions of mandible 104 incision, single 63 thyroidectomy incision, extension of 82f wedge excision of lateral tongue lesion, design of 44f Trismus 59, 104 Trunk of facial nerve 92 identification of main 93 Tumor cuts in transoral laser micro surgery 109f other 99 Tympanomastoid suture line 93

U Upper aerodigestive tract 115 Upper gingivobuccal sulcus 28 Upper neck skin crease 90, 99

V Vagus nerve 83 Valsalva maneuver 75 Vascularity of accessory nerve, preserva tion of 74 Vermilion border of lip to create vermilion MOUND 43f Vertical partial laryngectomy 59

W Waste-disposal buckets 4 Weber-Ferguson incision 26, 27f, 37, 38f Wharton’s duct 97

X Xeroform gauze 32

Z Z-plasties, series of 56 Zygomatic arch 37