Transoral Neck Surgery 3030307212, 9783030307219

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Transoral Neck Surgery Jonathon O. Russell William B. Inabnet III Ralph P. Tufano Editors

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Transoral Neck Surgery

Jonathon O. Russell  •  William B. Inabnet III Ralph P. Tufano Editors

Transoral Neck Surgery

Editors Jonathon O. Russell Otolaryngology – Head and Neck Surgery Johns Hopkins Medicine Otolaryngology –­ Head and Neck Surgery Baltimore, MD USA

William B. Inabnet III Department of Surgery University of Kentucky Lexington, KY USA

Ralph P. Tufano Otolaryngology – Head and Neck Surgery Johns Hopkins Medicine Otolaryngology – Head and Neck Surgery Baltimore, MD USA

ISBN 978-3-030-30721-9    ISBN 978-3-030-30722-6 (eBook) https://doi.org/10.1007/978-3-030-30722-6 © Springer Nature Switzerland AG 2020 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

To our patients, whose courage and trust made this possible.

Preface

“It’s not the things you don’t know that hurt you. It’s the things you think you know that aren’t true.” “If you always do what you’ve always done, you’ll always get what you’ve always got.” – Henry Ford

For more than 100 years, thyroid surgery has been performed through a central neck incision as demonstrated by Theodor Kocher. The endurance of the technique with only minor modifications is a testament to the elegance of the procedure and the excellent outcomes that can be expected when performed by experienced surgeons. While this excellence is the ultimate goal of all surgical procedures, it has left little room for significant innovation. Despite advances in energy devices, nerve monitoring, and even preoperative imaging, the actual approach itself has been inviolable: patients should expect a cervical incision that will generally heal well but will always leave a permanent scar. Our knowledge of thyroid cancer, molecular markers, prognostication, observation, and thyroid pathology has also grown. With recent updates in management recommendations such as the 2015 American Thyroid Association Guidelines for the Management of Thyroid Nodules, less surgery is recommended for small cancers. Indeed, observation of some tumors in appropriate clinical scenarios can be considered in the appropriate clinical context. And so, focus shifts again to the morbidity of the Kocher incision for three reasons. First, we now understand that most small thyroid cancers will not become clinically relevant. Second, most cytologically indeterminate nodules will be benign on final pathology, while any malignancies will generally be indolent. And finally, surgeon-directed ultrasound and widely available molecular markers offer the ability to provide excellent positive and negative predictive values even before a patient opts for surgery. When patients choose to undergo elective and prophylactic surgery for indolent pathology, there is very little room for any morbidity – even something as simple as a scar.

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This desire for constant improvement therefore brings us to the transoral endoscopic thyroidectomy via a vestibular approach (TOETVA). Offering multiple advantages over previous remote access approaches, the technique offers the potential to avoid a cervical incision while offering similar outcomes, a similar expense profile, and accessibility for most patients and surgeons. There is much that is unknown about TOETVA. This text is dedicated to those pioneering patients and surgeons who have moved to answer these questions. Baltimore, MD, USA Baltimore, MD, USA New York, NY, USA

Jonathon O. Russell Ralph P. Tufano William B. Inabnet III

Contents

1 History and Evolution of Transoral Thyroidectomy Approach����������    1 Tahar Benhidjeb, Kai Witzel, Jan Schulte am Esch, Michael Stark, Mohammad Shaear, and Ralph P. Tufano 2 The Ethics of Novel Surgical Techniques����������������������������������������������   17 Peter Angelos, Gregory Randolph, and Raymon H. Grogan 3 Alternative Remote Access Approaches to Endocrine and Neck Surgery������������������������������������������������������������������������������������   25 Meghan E. Garstka, David J. Terris, and Emad Kandil 4 Patient Selection for Thyroidectomy and Parathyroidectomy Using the Transoral Endoscopic Vestibular Approach ������������������������   41 Zhen Gooi and Jeremy D. Richmon 5 The Role of Ultrasound in Transoral Endocrine Surgery��������������������   49 Eyas Alkhalili and Jason D. Prescott 6 Lobectomy Versus Total Thyroidectomy in Suspicious or Malignant Thyroid Nodules ��������������������������������������������������������������   63 Jennifer S. Mammen and David S. Cooper 7 Surgical Equipment, Supplies, and Setup for Transoral Thyroid and Parathyroid Surgery via the Vestibular Approach ��������   77 Young Jun Chai, Özer Makay, Che-Wei Wu, Hoon Yub Kim, and Gianlorenzo Dionigi 8 Transoral Endoscopic Vestibular Approach Technique: Steps, Tips, and Pearls ����������������������������������������������������������������������������  121 Angkoon Anuwong, Khwannara Ketwong, Tanyanan Jamikorn, Isariya Jongekkasit, Thanyawat Sasanakietkul, and Pornpeera Jitpratoom

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9 Benign Nodules and Goiters��������������������������������������������������������������������  145 Gustavo G. Fernandez Ranvier, Aryan Meknat, and Hyunsuk Suh 10 Transoral Management of Indeterminate Thyroid Nodules����������������  159 Insoo Suh and Quan-Yang Duh 11 Transoral Endoscopic Vestibular Approach for Management of Thyroid Malignancies��������������������������������������������������������������������������  173 James H. Clark and Andrew T. Day 12 Graves’ Disease����������������������������������������������������������������������������������������  191 Jonathan Yoon, Christopher Razavi, Anery Patel, and Eun Hae Estelle Chang 13 Transoral Vestibular Approach Parathyroidectomy: Patient Selection Considerations and Technique����������������������������������  203 Toni Beninato, Elya Vasiliou, and Jonathon O. Russell 14 Special Considerations: Obesity, Reoperation to Transoral Endocrine, and Neck Surgery������������������������������������������  221 Pornpeera Jitpratoom, Thanyawat Sasanakietkul, Isariya Jongekkasit, Rohit Ranganath, and Angkoon Anuwong 15 Central Neck Dissection for Transoral Endoscopic Thyroidectomy Vestibular Approach ����������������������������������������������������  247 Gianlorenzo Dionigi, Hoon Yub Kim, Elya Vasiliou, and Ralph P. Tufano 16 Transoral Robotic Thyroidectomy ��������������������������������������������������������  261 Hoon Yub Kim, Gianlorenzo Dionigi, and Özer Makay 17 Decision-Making Process in Converting to an Open Approach����������  273 Vaninder K. Dhillon and Elizabeth E. Cottrill 18 Transoral Endoscopic Thyroidectomy Vestibular Approach Complications and Safety: Reporting Objectives and Future Study Design������������������������������������������������������������������������  281 Raymon H. Grogan Index������������������������������������������������������������������������������������������������������������������  293

Contributors

Eyas  Alkhalili, MD  Department of Surgery, Texas Tech University Health Sciences Center, El Paso, TX, USA Peter Angelos, MD, PhD  Division of Endocrine Surgery, Department of Surgery and MacLean Center for Clinical Medical Ethics, The University of Chicago, Chicago, IL, USA Angkoon  Anuwong, MD, FRCST, FACS  Minimally Invasive and Endocrine Surgery Division, Department of Surgery, Police General Hospital, Bangkok, Thailand Tahar Benhidjeb, MD, PhD  Center of Visceral Medicine, Department of General and Visceral Surgery, Bethel Clinic, Bielefeld, Germany Toni  Beninato, MD  Weill Cornell Medicine, New  York Presbyterian Brooklyn Methodist Hospital, Brooklyn, NY, USA Young  Jun  Chai, MD  Department of Surgery, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, South Korea Eun Hae Estelle Chang, MD, MPH  Department of Otolaryngology, University of Nebraska Medical Center, Omaha, NE, USA James H. Clark, MD  Department of Otolaryngology – Head and Neck Surgery, The Johns Hopkins School of Medicine, Baltimore, MD, USA David S. Cooper, MD  Division of Endocrinology, Diabetes and Metabolism, The Johns Hopkins School of Medicine, Baltimore, MD, USA Elizabeth  E.  Cottrill, MD  Department of Otolaryngology–Head and Neck Surgery, Thomas Jefferson University, Philadelphia, PA, USA Andrew  T.  Day, MD, MPH  Department of Otolaryngology  – Head and Neck Surgery, University of Texas – Southwestern Medical Center, Dallas, TX, USA

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Vaninder K. Dhillon, MD  Division of Laryngology and Head and Neck Endocrine Surgery, Department of Otolaryngology, The Johns Hopkins School of Medicine, Baltimore, MD, USA Gianlorenzo Dionigi, MD, FACS  Division of Endocrine and Minimally Invasive Surgery, University of Messina, Varese, Italy Quan-Yang  Duh, MD  Endocrine Surgery Section, Department of Surgery, University of California, San Francisco, CA, USA Jan Schulte am Esch  Evangelisches Klinikum Bethel, Department of General and Visceral Surgery, Bielefeld, Germany Gustavo G. Fernandez Ranvier, MD, PhD  Division of Metabolic, Endocrine and Minimally Invasive Surgery, Department of Surgery, Mount Sinai Hospital, Icahn School of Medicine at Mount Sinai, New York, NY, USA Meghan E. Garstka, MD, MS  Department of Surgery, Tulane University School of Medicine, New Orleans, LA, USA Zhen  Gooi, MBBS  Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Chicago, Chicago, IL, USA Raymon H. Grogan, MD, MS, FACS  Baylor St. Luke’s Medical Center, Michael E.  Debakey Department of Surgery, Baylor College of Medicine, Houston, TX, USA Tanyanan  Jamikorn  Minimally Invasive and Endocrine Surgery Division, Department of Surgery, Police General Hospital, Bangkok, Thailand Pornpeera  Jitpratoom  Minimally Invasive and Endocrine Surgery Division, Department of Surgery, Police General Hospital, Bangkok, Thailand Isariya  Jongekkasit  Minimally Invasive and Endocrine Surgery Division, Department of Surgery, Police General Hospital, Bangkok, Thailand Emad Kandil, MD, MBA, MBA, FACS, FACE  Department of Surgery, Tulane University School of Medicine, New Orleans, LA, USA Khwannara  Ketwong, MD  Department of Surgery, Chiang Rai Prachanukroh Hospital, Chiang Rai, Thailand Hoon  Yub  Kim, MD, PhD, FACS  Department of Surgery, Korea University College of Medicine, Seoul, South Korea Korea University Hospital, Seoul, South Korea Özer Makay, MD, FEBS  Division of Endocrine Surgery, Ege University Hospital, Bornova, Izmir, Turkey Jennifer  S.  Mammen, MD, PhD  Division of Endocrinology, Diabetes and Metabolism, The Johns Hopkins School of Medicine, Baltimore, MD, USA

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Aryan Meknat, MD  Department of Surgery, Mount Sinai Hospital, Icahn School of Medicine at Mount Sinai, New York, NY, USA Anery  Patel, MBBS  Department of Internal Medicine, Division of Diabetes, Endocrine and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA Jason  D.  Prescott, MD, PhD  Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA Gregory  Randolph, MD, FACS, FACE  Harvard Medical School, Boston, MA, USA Comprehensive Otolaryngology and Thyroid/Parathyroid Endocrine Surgical Divisions, Massachusetts Eye and Ear Infirmary, Boston, MA, USA Rohit Ranganath  Division of Head and Neck Endocrine Surgery, Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA Christopher Razavi, MD  Department of Otolaryngology – Head & Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA Jeremy D. Richmon, MD  Head and Neck Surgical Oncology and Reconstructive Surgery, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA Jonathon O. Russell, MD  Department of Otolaryngology – Head & Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA Thanyawat  Sasanakietkul, MD, FRCST  Minimally Invasive and Endocrine Surgery Division, Department of Surgery, Police General Hospital, Bangkok, Thailand Mohammad Shaear, MD  Department of Otolaryngology – Head & Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA Michael Stark  The New European Surgical Academy (NESA), Berlin, Germany Hyunsuk Suh, MD  Department of Surgery, Mount Sinai Beth Israel, Icahn School of Medicine at Mount Sinai, New York, NY, USA Insoo Suh, MD  Endocrine Surgery Section, Department of Surgery, University of California, San Francisco, CA, USA David  J.  Terris, MD  Augusta University Thyroid and Parathyroid Center, Department of Otolaryngology  – Head & Neck Surgery, Augusta University, Augusta, GA, USA Ralph  P.  Tufano, MD, MBA  Department of Otolaryngology  – Head & Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA

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Elya Vasiliou, MD  Department of General Surgery, University of Vermont Medical Center Porter Hospital, Middlebury, VT, USA Kai Witzel  Minimally Invasive Center, Hünfeld, Germany Che-Wei  Wu, MD, PhD  Department of Otorhinolaryngology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University Hospital, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan Jonathan  Yoon, MD  Department of Otolaryngology, University of Nebraska Medical Center, Omaha, NE, USA

Chapter 1

History and Evolution of Transoral Thyroidectomy Approach Tahar Benhidjeb, Kai Witzel, Jan Schulte am Esch, Michael Stark, Mohammad Shaear, and Ralph P. Tufano

A Brief History of Thyroid Surgery Thyroid surgery has had an illustrious past. The earliest distinct reference of a successful attempt at surgical treatment of goiter is present in the medical writings (“Al Tasrif”) by the Moorish physician Ali Ibn Abbas or Albucasis in about 952 AD. His experience is recorded as the removal of a large goiter under sedation with opium with the use of simple ligatures along with hot cautery irons as the patient sat with a bag tied around his neck to collect the blood from the wound [1]. Although there have been earlier reports of similar surgeries, their validity has not been warranted. Thereafter, it passed through a series of crests and troughs over the ages as its proponents and opponents held sway in the medical field over different periods of time. At one point of history, thyroid surgery was considered such a dreaded operation with a definite grim outcome that surgeons were fearful in performing it at all [2]. Halsted, in his The Operative History of Goitre, scrutinized procedures done before 1850 and analyzed them to be associated with 40% mortality [3]. The high mortality was mainly due to hemorrhage, asphyxia due to tracheal compression, T. Benhidjeb (*) Center of Visceral Medicine, Department of General and Visceral Surgery, Bethel Clinic, Bielefeld, Germany K. Witzel Minimally Invasive Center, Hünfeld, Germany J. Schulte am Esch Evangelisches Klinikum Bethel, Department of General and Visceral Surgery, Bielefeld, Germany M. Stark The New European Surgical Academy (NESA), Berlin, Germany M. Shaear · R. P. Tufano Department of Otolaryngology – Head & Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA © Springer Nature Switzerland AG 2020 J. O. Russell et al. (eds.), Transoral Neck Surgery, https://doi.org/10.1007/978-3-030-30722-6_1

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hospital gangrene and air embolism, or the then almost inevitable sepsis. Surgical relief was invoked for severe disfigurement, dyspnea, or dysphagia. The sequelae were often mediastinitis with or without abscess formation, phlegmon and fistula of the neck, erysipelas, pyxemia, tetanus, lung and pleura inflammation, tetany, and cachexia strumipriva [4]. These drawbacks made even the most skilled surgeons jittery, and they avoided operating on goiters. In the mid-nineteenth century, thyroid surgery was regarded as a “proceeding by no means to be thought of” in Britain, “foolhardy” in Europe, and “horrid butchery” in America. The French National Academy of Medicine banned thyroid operations in 1850 due to the high mortality associated with them [5]. Thyroid surgery started coming out of its doldrums in the middle of the nineteenth century. This was due to the concerted improvement in anesthesia, infection prophylaxis, and better hemostasis. With all these advances, the surgical stage was well set for the advent of the most skilled surgeons of the nineteenth century. By the mid-twentieth century, the contributions of Billroth, Kocher, Halsted, Mayo, Crile, Lahey, and Dunhill altogether resolved the difficulties of modern thyroid surgery, as espoused by Dieffenbach, Liston, and Gross a century earlier [5]. Among them, Theodor Kocher stands colossal over the field of thyroid surgery and has been universally and deservedly acclaimed as the Father of Thyroid Surgery (Fig. 1.1). In 1917, a few weeks before his death at the age of 76, he made his final appearance before the Swiss Surgical Congress, reviewing his entire surgical experience with goiter, reporting on approximately 5000 operations with a mortality rate of about 0.5% [6]. It is thus no wonder that he is the first surgeon to ever receive the Nobel Prize in Medicine and Physiology, presented in 1909 to honor his life’s work in trying to understand thyroid disease through surgery and research. The principles of thyroid surgery as described by Theodor Kocher are still valid and became the foundation for all future refinements. The highly standardized technique and the introduction of new technology have made it one of the safest procedures in surgery today with very low morbidity. Apart from making the surgery safe and effective, the quest started for newer techniques of performing the procedure to achieve cosmetically better results and overcoming its other drawbacks.

New Millennium Thyroid surgery has followed all the steps of evolution to reach the time of endoscopic surgery. With the advent of minimally invasive surgery in the early 1980s, endoscopic procedures have become standard in nearly all surgical fields. In thyroid surgery this effect started later since it is more difficult to use an endoscopic approach to the thyroid gland due to its location in the neck. All the requisite working space has to be created, because there is no natural cavity. However, mediastinoscopy, retroperitoneoscopy, and total extraperitoneal endoscopic hernioplasty have familiarized us with ways of creating the needed operative space in similar scenarios.

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Fig. 1.1  Theodor Kocher (1841–1917)

Usually, the main advantages of minimally invasive procedures are less pain, less bleeding, less infection risk, a faster recovery, and better cosmetic results achieved by smaller scars. By now, we know that the demand for cosmetic surgery is high and increasing, because these results are obvious. The technique of minimally invasive video-assisted thyroidectomy (MIVAT) developed by Miccoli et al. [7] is the method that has so far become most widespread. Limiting factors of this method include the need for a 20-mm cervical incision and consequently the specimen size to be removed (Figs. 1.2 and 1.3). Because visible neck scarring can be very stigmatizing for Asian women, several authors published studies describing an access avoiding a scar in the neck. Such approaches are via the chest, axillary, a combined axillary bilateral breast, or a bilateral axillary breast approach [8, 9]. The development of cervical scarless thyroid surgery is a great step toward better cosmetic outcomes. However, these techniques just moved the scars from the front neck region to the axilla or the chest where they are still visible. The mentioned cervical conventional and the minimally invasive

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Fig. 1.2  MIVAT technique

Fig. 1.3  MIVAT 5 years postoperative

access to the thyroid gland do not respect the anatomically given surgical planes, e.g., cutting of the skin and platysma and dividing of the strap muscles. Furthermore, all reported extracervical approaches do not comply with the use of the term “minimally invasive,” because they are associated with an extensive dissection of the chest and neck region, thus being rather maximally invasive for the patient (Figs. 1.4 and 1.5). All the abovementioned disadvantages were our driving force in the creation of the transoral access.

Idea and Rationale Behind the Transoral Thyroidectomy Transoral thyroid surgery was initiated worldwide for the first time in September 2007 by the New European Surgical Academy (NESA; www.nesacademy.org) as part of the NESA’s Natural Orifice Surgery project that includes investigation of

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Fig. 1.4 Axillo-bilateral breast approach (ABBA) technique

Fig. 1.5  ABBA first postoperative day

transvaginal and transoral access for various surgical procedures [10–12]. The main goal of this interdisciplinary project was to introduce a thyroid resection technique that fulfills the following criteria: 1 . Respecting surgical planes and minimizing surgical trauma in thyroidectomy. 2. The access itself should be close to the thyroid gland to achieve a minimally invasive procedure.

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3. Achieving an optimal cosmetic result may only be obtained by performing a scarless operation. 4. This optimal cosmetic result with scarless surgery should be achieved with minimal trauma. 5. The minimally invasive character of this approach and the optimal cosmetic result should not be reached at the expense of patient’s safety. We were of the opinion that the technique that meets all of these criteria is the transoral access because the distance between the sublingual or floor of the mouth and the thyroid gland is short, thus avoiding extensive dissection. Furthermore, the mouth mucosa can be sutured without difficulty and usually repairs itself without leaving any visible scars. Feasibility of the transoral access had been demonstrated for the first time in 2008 by our team member Kai Witzel, who used a modified 20-mm axilloscope through an infralingual incision in a porcine model. However, the described technique was a hybrid one because of an additional 3.5-mm cervical skin incision [13]. For this reason, the main goal of our interdisciplinary team was the development of a new, totally transoral, thyroidectomy technique.

Preclinical Investigations Initially, our strategy consisted of checking the literature for reports dealing with the transoral surgery in general and transoral thyroidectomy in particular. In the next two steps, we performed extensive studies of the surgical anatomy of the floor of the oral cavity and the cervical spaces on human cadavers and the application of the transoral access on living pigs [14–17].

Transoral Surgery in the Literature The main aim of this search was the evaluation of the reported transoral approaches with regard to morbidity in general and infection in particular. The complication that many surgeons fear is contamination of the surgical site with oropharyngeal flora, especially since conventional thyroidectomy is a sterile surgical procedure. Our investigation showed that a totally transoral approach to the thyroid had never been described before. However, we found papers describing a transoral access in different disciplines including neurosurgery regarding the clivus and anterior cervical spines, but we will focus on the transoral approach reported by otolaryngology– head and neck surgeons and plastic surgeons regarding the submandibular gland and sublingual gland since they are closely related to the novel transoral thyroid access. On January 22, 1960, D. Downton and G. Qvist reported in a case series a novel technique to expose the submandibular gland through the mouth by incision of the mylohyoid muscle. They proposed this technique as an alternative to the standard

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cervical incision. The advantage of this approach was not only cosmetic but also avoided the injury of the mandibular branch of the facial nerve. Two out of eight patients had postoperative infection. There was no permanent injury to the mandibular branch of the facial nerve or the hypoglossal nerve. However, one patient had paresthesia to the side of the tongue mostly due to contusion of the lingual nerve by retraction [18]. This discovery was based on Downton’s observations during the resection of the mylohyoid ridge as a surgical aid to the prosthetic problem of the atrophied lower alveolar ridge [19]. Later in 2000, Ki Hwan Hong and Young Ki Kim [20] published a case series of 31 patients who underwent a modified transoral technique for removal of ­submandibular gland. This technique was different from Downton’s technique as the incision was done through the mucosa, not the mucoperiosteum. The long-term outcome reported was only physical but not symptomatic restriction of tongue movement. However, the short-term outcomes were significant for abnormal sensation and limited movement of the tongue. Eight years later, Hong KH published a retrospective chart review of 77 patients who underwent intraoral submandibular gland removal [21, 22]. Guerrissi JO and his team reported the use of endoscope in performing this technique. The endoscope provided good illumination and magnification and therefore less dissection and damage to tissues and surrounding blood vessels and nerves [23]. The experience with ranula, which usually developed from the minor salivary glands and the sublingual gland in the floor of the mouth, was evaluated. The treatment varied between marsupialization, simple excision, and transcervical excision. Furthermore, the intraoral approach was deemed a safe and effective technique in managing this condition. The intraoral excision of ranula is described in the literature [24–27] . Through an incision from the orifice of Wharton’s duct to the lingual side of the retromolar region on the mucosa of the lateral side of the floor of the mouth, the sublingual gland is dissected and removed with the isolation of the duct and the lingual nerve. This is followed by retraction of the mylohyoid muscle; the cystic capsule is seen and removed by dissection before suturing back the mucosa [24].

Anatomical Studies on Cadavers These extensive anatomical studies of the surgical anatomy of the floor of the oral cavity and the cervical spaces were performed on human cadavers [16]. Our hypothesis was that a working space under the platysma muscle in the anterior neck region (level VI) can be created with respect to the surgical planes and fascial layers of the neck and without significant damage to anatomical structures, such as vessels and nerves. Within this area, it should be possible to reach the vessels and lymph nodes under the sternocleidomastoid muscle as well as the pretracheal region. In this compartment, the thyroid can be visualized and resected. The main aim of these studies was to define anatomical spaces, surgical planes, and related neural and vascular structures of the frontal and lateral neck region and to create a safe and reproducible access through the floor of the oral cavity and pathway to the cervical spaces. To qualitatively determine damage to anatomically relevant structures, all specimens were dissected after performing the surgical procedure [16].

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In a first attempt consisting of an exclusively sublingual access, a trocar for optical information with a 3-mm Hopkins endoscope (Karl Storz GmbH, Tuttlingen, Germany) was placed in the midline between and before the papillae of Wharton’s duct. The endoscope passed the muscles of the floor of the oral cavity easily without damage to relevant anatomical structures. The muscles of the floor of the oral cavity are separated bilaterally in the midline. No vessels or nerves are present in this area, and hence, there are no structures at risk. To get access for our 3-mm working trocars, we passed the floor of the oral cavity sublingually on both sides through the submandibular triangle. A major disadvantage of the sublingual access was not only the minimal triangulation of the working instruments, which only reaches 5.8°, but much more—All the structures running in the sublingual and the submandibular space, including submandibular and sublingual glands, lingual nerve, sublingual artery and vein, hypoglossal nerve, and facial artery. Under these aspects, it was clear that this approach was not applicable [16]. Consequently, we changed our transoral exclusively sublingual approach to a combined bivestibular and sublingual access. The optic trocar remained in the midline sublingually, but the working trocars were moved to the vestibule of oral cavity bilaterally beneath the incisive teeth of the mandible (Fig.  1.6). Through a 5-mm Fig. 1.6  TOVAT principle

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incision in the mucosa of the vestibule, we were able to reach the periosteum of the mandible directly and pass under the platysma muscle and the superficial fascia to get access to the infrahyoidal working space. By entering the plane under the superficial fascia, it was possible to avoid damage to the marginal branch of the facial nerve as well as damage to the facial vein. The only structure at risk is the mental nerve (third branch of the trigeminal nerve) when the vestibular working trocars are brought in place: this nerve usually is located directly under the submucosa of the oral vestibule and can be identified easily. Blunt submucosal dissection helps in securing intact function of those nerves. All performed anatomical dissections after the transoral combined bivestibular approach showed that all relevant structures, muscles of the floor of the oral cavity, as well as all vessels and nerves were intact. Furthermore, the triangulation of the instruments reached an acceptable 20° to 30° [16]. With this method, we performed the first successful endoscopic thyroidectomy on human cadavers using a three-point exclusively transoral access on May 14, 2008 (Fig. 1.7). We called this technique totally transoral video-assisted thyroidectomy (TOVAT). The acronym TOVAT describes precisely the route (transoral) and also refers to the methodology (totally video-assisted) (15). Furthermore, Richmond JD et al. reported on the same approach regarding the placement of the trocars but used a robotic technique. The team quickly realized the limitations of this approach with the robot and the need for a different approach. They are the first ones to our knowledge to report the tri-vestibular technique to reach the thyroid on a cadaver [28, 29]. Fig. 1.7  TOVAT: the first experimental case on May 14, 2008

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TOVAT Application on Living Animals It is worth mentioning that there are significant anatomical differences concerning the topographical anatomy of the thyroid gland between humans and animals [17]. The neck in pigs, for example, is much larger than in humans, thus enabling better triangulation and manipulation of instruments. Moreover, thyroidectomy in pigs is much easier to perform due to the peculiar anatomical relationships of the gland, its size (up to 5.0  mL in 4-month-old pigs), the absence of definite parathyroid glands, and its relatively simple blood supply. Therefore, we decided to resect parts of the thymus because of its vascular supply, thus ensuring a more realistic surgical setup during the operation. Furthermore, the main aim of these animal studies was to evaluate if TOVAT might lead to postoperative swallowing difficulties. Five male pigs were used in order to evaluate the feasibility and safety of the TOVAT technique on August 31, 2008. The pretracheal region could be reached without a problem, and the procedure was performed almost “bloodlessly” in an anatomically defined layer. Postoperative awakening was uneventful. Perioperative antibiotics were administered, and oral intake and behavior were observed during the following 2 days. Regular and normal oral food intake was observed after 2 to 3 hours in all animals. On the third postoperative day, all pigs were anesthetized, and the incision sites in the oral cavity were checked. Furthermore, a complete dissection of the floor of mouth and the anterior cervical region, including the surgical field, was performed to reveal infections, hematomas, or other collateral damage. At the end, the animals were subsequently euthanized. After dissection, the whole operation site appeared inconspicuous (no infections, fresh/old hematoma). Histopathologically, only a mild tissue reaction was noted [17].

Drawbacks Following Premature Clinical Implementation When a new suggested surgical method departs substantially from current standard of care, scientific evaluation is a conditio sine qua non [30]. Feasibility and safety must be secured before starting clinical application that has tremendous implications regarding expectations, surgeon responsibility, and most importantly patient safety.

Concerns Regarding Our TOVAT Technique Although we were able to demonstrate the surgical feasibility of TOVAT as early as 2008 [14, 15], as a result of our extensive anatomical investigations on human cadavers and living pigs, we had serious concerns about the safety of its clinical implementation. The main reason was the cervical region itself, which is rich in vulnerable structures. Even if the surgical approach is solely performed through a

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midline incision at the floor of the mouth by using the natural midline dehiscence between the genioglossus muscles and despite the fact that this area is a relatively avascular dissection plane, we believe that every inserted instrument would cause a permanent mechanical friction with the surrounding soft tissue and muscular structures. This would lead, in the best case, to mild inflammatory reactions and, in the worst case, to hematoma formation. End stage of the reparation processes in this area would inevitably be scar formation with subsequent swallowing disorders. To the best of our knowledge, there are no data concerning the maximum diameter of an instrument that might be introduced and the specimen volume that can be removed through the floor of the mouth. Furthermore, we clearly demonstrated that the submandibular triangle is a no-go area for any trocar or instrument insertion and manipulation because of the risk of bleeding and harming of neural structures, e.g., paresis of the hypoglossal nerve resulting in dysgeusia. Because of these anatomical findings and the potential complications, we consequently changed our transoral exclusively sublingual approach to a combined bivestibular and sublingual access. Considering all these aspects and the above described issues and other crucial points, we initially decided at that time not to proceed to clinical application before further preclinical investigation results were available, but others disagreed [31, 32]. Wilhelm and Metzig [31, 32] encountered all the above predicted difficulties and concerns resulting in severe complications, such as paresthesia of the mental nerve in varying degrees in seven of eight cases (87.5%), conversion to open surgery due to specimen size in three of eight cases (37.5%), palsy of the recurrent laryngeal nerve in two of eight cases (25%), one permanent RLN paralysis (12.5%), and local streptococci infection at the vestibular incision site necessitating incision and irrigation in one case (12.5%). With these serious adverse events, they stopped their proof-of-concept study [33, 34]. A further drawback due to the early application of transoral access was reported by Karakas et al. [35] who presented the results of their pilot study on five patients with primary hyperparathyroidism who underwent a so-called transoral partial parathyroidectomy (TOPP) [35]. The access via the sublingual access was performed more dorsally, directly in front of the trachea. In two patients, the procedure had to be converted to the conventional technique. One patient had transient recurrent laryngeal nerve palsy, while one patient suffered from a transient palsy of the right hypoglossal nerve with persisting dysgeusia. Three patients developed swallowing problems. In four patients, the visual analog scale pain score was high. Also here, the authors terminated their study because of the severe complications. The preliminary tests of Karakas et al. [36] from 2010 were limited to the investigation of best fitting instruments to gain access to the thyroidal region by using animal cadavers. Additionally within these initial tests, the feasibility to reach the parathyroid and thyroid glands via an entirely transoral paralingual access behind the strap muscles was investigated. TOPP set up the space at the dorsal side of the thyroid gland and adjacent to the trachea. The hypoglossal nerve and the lingual nerve as well as their accompanying blood vessels were anatomically related to the approach and could be injured during the procedure [37]. They concluded that “TOPP is non-

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sense with currently available devices.” This reemphasized our concern about the submandibular triangle as a no-go area for any trocar or instrument insertion and manipulation.

Clinical Breakthrough of the Transoral Thyroidectomy We were from the beginning convinced that the transoral thyroid surgery is a promising approach because it is the only method which is at the same time minimally invasive and cosmetically optimal. Naturally predetermined cervical layers are being separated instead of being cut and divided. Furthermore, the vestibular mucosa can be sutured directly and repairs itself without leaving any visible scars. Fortunately, there were some papers from Asia reporting on a successful clinical application of the transoral thyroidectomy [reviews in 38–42]. The most impressive report was from Angkoon Anuwong, who presented his initial experience with the transoral endoscopic thyroidectomy vestibular approach (TOETVA) [39]. The primary difference between TOVAT and TOETVA is the placement of the 10-mm trocar at the center of the oral vestibule, while ours was introduced through the mouth floor [15]. The two 5-mm trocars were inserted at the junction between the incisor and canine on both sides pointing down to the anterior neck under direct laparoscopic vision. A series of 60 procedures was accomplished successfully. Forty-two patients had single-thyroid nodules, and a lobectomy was performed. Twenty-two patients had multinodular goiters and two patients had Graves’ disease, with total thyroidectomy or Hartley-Dunhill procedures performed. It is worthy of mention that two of these patients had papillary thyroid carcinoma where total thyroidectomy with central node dissection was done. The median operative time was 115.5 minutes (range, 75–300 minutes). The median blood loss was 30 mL (range, 8–130 mL). Two patients experienced a transient hoarseness, which resolved within 2  months. One patient experienced a late postoperative hematoma, which was treated conservatively. No mental nerve injury or infections were found. The patients were discharged in an average of 3.6 days (range 2–7 days) postoperatively [39]. In the meantime, Anuwong performed TOETVA on more than 400 patients with similar good outcome [43]. The complication rate is low and similar to that of conventional thyroidectomy. The decisive step in TOETVA is the bypassing of the floor of mouth, thus avoiding all structures in the submandibular triangle at risk. However, as described above, the main concern in the vestibular technique might be the mental nerve which is in striking distance to the two 5-mm trocars. Chai YJ and Kim HY reported about this matter in a retrospective cohort study comparing two different approaches to the thyroid. Each group had 50 patients and they underwent either bilateral axillo-breast approach (between 2008 and 2009) or transoral vestibular approach (between 2012 and 2016). They encountered mental nerve injury in the first 12 cases. However, they did not encounter any mental nerve injuries after moving the midline incision to the tip of gingivolabial frenulum and the lateral incisions to 1-cm medial to the mouth angle (lip commissure) [32].

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Conclusions and Future Considerations The concept of natural orifice surgery (NOS/NOTES) has changed the surgeon’s perspective; natural openings of the body are used by interdisciplinary teams to reach the target region directly, thereby causing minimal tissue trauma. The aim is to reduce collateral damage and complications and to speed recovery of the patient [11]. Transoral thyroidectomy is based on entering and sliding along anatomically defined layers and planes directly, thus avoiding laceration and division of the cervical muscle layers, especially the platysma muscle. The transoral access to the thyroid represents only the first station, since this approach enables dissection and visualization of the whole mediastinum as demonstrated in our animal experiments [17]. Transoral mediastinal lymph node dissection might become an alternative to the conventional mediastinoscopy for mediastinal staging and surgery. Transoral thymectomy might replace the transcervical approach or the video-­ assisted thoracoscopic surgery or single-port thymectomy. An up-to-down dissection of the esophagus until the esophago-gastral junction is surely feasible and worthy to investigate as alternative to thoracotomy and thoracoscopy with its ­associated high morbidity, in particular with regard to postoperative acute and chronic chest wall pain. Beyond any doubt, natural orifice surgery (NOS/NOTES) is the next step in the evolution of minimally invasive surgery, and transoral thyroidectomy is a part of it. It represents a breakthrough for the patient and a paradigm shift in the history of thyroid surgery toward a scarless and possibly yet to be recognized improvement in quality of life. Last but not least, the concept and history of the transoral thyroidectomy also is a reminder of the importance to proceed in an ethical and scientific fashion when implementing novel procedures [41, 42].

References 1. Haddad FS. Abulcasis. Abbottempo. 1968;3:22–5. 2. Sarkar S, Banerjee S, Sarkar R, Sikder B. A review on the history of ‘thyroid surgery’. Indian J Surg. 2016;78:32–6. 3. Halsted WS. The operative history of goiter. The author’s operation. Johns Hopkins Hosp Rep. 1920;19:71–257. 4. Hegner CF. A history of thyroid surgery. Ann Surg. 1932;95:481–92. 5. Hannan SA.  The magnificent seven: a history of modern thyroid surgery. Int J Surg. 2006;4:187–91. 6. Becker WF.  Presidential address: pioneers in thyroid surgery. Ann Surg. 1977;185: 493–504. 7. Miccoli P, Berti P, Coute M, Bendinelli C, Marcocci C. Minimally invasive surgery for thyroid small nodules: preliminary report. J Endocrinol Investig. 1999;22:849–51. 8. Benhidjeb T, Anders S, Bärlehner E.  Total video-endoscopic thyroidectomy via axillo-­ bilateral-­breast-approach (ABBA). Langenbeck's Arch Surg. 2006;391:48–9.

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9. Bärlehner E, Benhidjeb T. Cervical scarless endoscopic thyroidectomy: axillo-bilateral-breast approach (ABBA). Surg Endosc. 2008;22:154–7. 10. Benhidjeb T, Witzel K, Baerlehner E, Stark M. The natural orifice surgery concept. Vision and rationale for a paradigm shift. Chirurg. 2007;78:537–42. 11. Stark M, Benhidjeb T.  Natural orifice surgery: transdouglas surgery–a new concept. JSLS. 2008;12:295–8. 12. Benhidjeb T, Burghardt J, Stark M. Novel technologies for natural orifice surgery: an overview. Minim Invasive Ther Allied Technol. 2008;17:346–54. 13. Witzel K, von Rahden BHA, Kaminski C, Stein HJ. Transoral access for endoscopic thyroid resection. Surg Endosc. 2008;22:1871–5. 14. Benhidjeb T, Wilhelm T, Harlaar J, Kleinrensink GJ, Schneider TAJ, Stark M. Totally transoral video-assisted thyroidectomy (TOVAT): first experimental results of a new surgical method. Minim Invasive Ther Allied Technol. 2008;17:217. 15. Benhidjeb T, Wilhelm T, Harlaar J, Kleinrensink GJ, Schneider TAJ, Stark M. Natural orifice surgery on thyroid gland: totally transoral video-assisted thyroidectomy (TOVAT): report of first experimental results of a new surgical method. Surg Endosc. 2009;23:1119–20. 16. Wilhelm T, Harlaar J, Kerver A, Kleinrensink GJ, Benhidjeb T. Surgical anatomy of the floor of mouth and the cervical spaces as a rationale for trans-oral, minimal-invasive endoscopic surgical procedures - results of cadaver studies. Eur Arch Otorhinolaryngol. 2011;267:1285–90. 17. Wilhelm T, Benhidjeb T. Transoral endoscopic neck surgery: feasibility and safety in a porcine model based on the example of thymectomy. Surg Endosc. 2011;25:1741–7. 18. Downton D, Qvist G.  Intra-oral excision of the submandibular gland. Proc R Soc Med. 1960;53:543–4. 19. Downton D. Mylohyoid ridge resection. Dent Rec. 1954;74:212. 20. Hong KH, Kim YK. Intraoral removal of the submandibular gland: a new surgical approach. Otolaryngol Head Neck Surg. 2000;122:798–802. 21. Hong KH, Yang YS.  Surgical results of the intraoral removal of the submandibular gland. Otolaryngol Head Neck Surg. 2008;139:530–4. 22. Hong KH, Yang YS.  Intraoral approach for the treatment of submandibular salivary gland mixed tumors. Oral Oncol. 2008;44:491–5. 23. Guerrissi JO, Taborda G.  Endoscopic excision of the submandibular gland by an intraoral approach. J Craniofac Surg. 2001;12(3):299–303. 24. Yang Y, Hong K.  Surgical results of the intraoral approach for plunging ranula. Acta Otolaryngol. 2014;134:201–5. 25. Huang SF, Liao CT, Chin SC, Chen IH.  Transoral approach for plunging ranula—10-year experience. Laryngoscope. 2010;120:53–7. 26. Zhao YF, Jia Y, Chen XM, Zhang WF. Clinical review of 580 ranulas. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004;98:281–7. 27. Packiri S, Gurunathan D, Selvarasu K. Management of Paediatric Oral Ranula: a systematic review. J Clin Diagn Res. 2017;11(9):ZE06–9. 28. Richmon JD, Pattani KM, Benhidjeb T, Tufano RP. Transoral robotic-assisted thyroidectomy: a preclinical feasibility study in 2 cadavers. Head Neck. 2011;33:330–3. 29. Richmon JD, Holsinger FC, Kandil E, Moore MW, Garcia JA, Tufano RP. Transoral robotic-­ assisted thyroidectomy with central neck dissection: preclinical cadaver feasibility study and proposed surgical technique. J Robot Surg. 2011;5(4):279–82. 30. Neugebauer EAM, On behalf of the EAES. EAES recommendations on methodology of innovation management in endoscopic surgery. Surg Endosc. 2010;24:1594–615. 31. Wilhelm T, Metzig A. Endoscopic minimally invasive thyroidectomy: first clinical experience. Surg Endosc. 2010;24:1757–8. 32. Wilhelm T, Metzig A. Endoscopic minimally invasive thyroidectomy (eMIT): a prospective proof-of-concept study in humans. World J Surg. 2011;35:543–51. 33. Benhidjeb T, Witzel K, Burghardt J, Bärlehner E, Stark M, Mann O. Endoscopic minimally invasive thyroidectomy: ethical and patients safety considerations on the first clinical expe-

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rience of an innovative approach. Surg Endosc. 2010;. Aug 24; https://doi.org/10.1007/ s00464-010-1290-9. 34. Benhidjeb T, Stark M.  Endoscopic minimally invasive thyroidectomy (eMIT): safety first! World J Surg. 2011;35:1936–7. 35. Karakas E, Steinfeldt T, Gockel A, Mangalo A, Sesterhenn A, Bartsch DK. Transoral parathyroid surgery–a new alternative or nonsense? Langenbeck’s Arch Surg. 2014;399:741–5. 36. Karakas E, Steinfeldt T, Gockel A, Westermann R, Kiefer A, Bartsch DK. Transoral thyroid and parathyroid surgery. Surg Endosc. 2010;24:1261–7. 37. Benhidjeb T, Witzel K, Stark M, Mann O.  Transoral thyroid and parathyroid surgery: still experimental! Surg Endosc. 2011;25:2411–3. 38. Witzel K, Hellinger A, Kaminski C, Benhidjeb T.  Endoscopic thyroidectomy: the transoral approach. Gland Surg. 2016;5:336–41. 39. Anuwong A. Transoral endoscopic thyroidectomy vestibular approach: a series of the first 60 human cases. World J Surg. 2016;40:491–7. 40. Nakajo A, Arima H, Hirata M, Mizoguchi T, Kijima Y, Mori S, Ishigami S, Ueno S, Yoshinaka H, Natsugoe S.  Trans-oral video-assisted neck surgery (TOVANS). A new transoral technique of endoscopic thyroidectomy with gasless premandible approach. Surg Endosc. 2013 Apr;27(4):1105–10. 41. Benhidjeb T, Stark M, Gerntke I, Mynbaev O, Witzel K.  Transoral thyroidectomy  – from experiment to clinical implementation. Transl Cancer Res. 2017;6(Suppl 1):S174–8. 42. Witzel K, Messenbaeck F, Weitzendorfer M, Benhidjeb T. Transoral thyroidectomy: limitations, patients' safety, and own experiences. Updat Surg. 2017;69:193–8. 43. Anuwong A, Ketwong K, Jitpratoom P, Sasanakietkul T, Duh Q. Safety and outcomes of the transoral endoscopic thyroidectomy vestibular approach. JAMA Surg. 2018;153(1):21–7. https://doi.org/10.1001/jamasurg.2017.3366.

Chapter 2

The Ethics of Novel Surgical Techniques Peter Angelos, Gregory Randolph, and Raymon H. Grogan

Introduction When one considers the history of surgery, it is clear that progress has often followed the adoption of novel surgical approaches to solve patient problems. Unlike new drugs which must undergo rigorous testing in order to receive approval from the US Food and Drug Administration, new surgical techniques need only appear to the surgeon to be beneficial for a patient. In this manner, surgeons have not only the ability to try novel approaches to solve their individual patient’s problems, but they have the responsibility to try to creatively solve their patient’s problems. This process is often completed with little or no oversight. Within this context, it is helpful to consider three different scenarios. In the first scenario, a surgeon is faced with a particularly challenging tumor and the necessity for resection and reconstruction requires him or her to adopt an innovative approach. In this context, the surgeon is acting purely for the patient’s benefit, and there is no need for prior approval to use such an approach. The surgeon should disclose the innovative nature of the operation to the patient preoperatively if it is planned or, if unplanned, as soon as possible postoperatively [1]. Alternatively, if a surgeon has

P. Angelos Division of Endocrine Surgery, Department of Surgery and MacLean Center for Clinical Medical Ethics, The University of Chicago, Chicago, IL, USA G. Randolph Harvard Medical School, Boston, MA, USA Comprehensive Otolaryngology and Thyroid/Parathyroid Endocrine Surgical Divisions, Massachusetts Eye and Ear Infirmary, Boston, MA, USA R. H. Grogan (*) Baylor St. Luke’s Medical Center, Michael E. Debakey Department of Surgery, Baylor College of Medicine, Houston, TX, USA e-mail: [email protected] © Springer Nature Switzerland AG 2020 J. O. Russell et al. (eds.), Transoral Neck Surgery, https://doi.org/10.1007/978-3-030-30722-6_2

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utilized a novel approach in the past and now wants to determine if it is actually better, the arena of surgical research is entered. In this context, the planned innovation in the course of assessing its value should be part of a formal Institutional Review Board (IRB) protocol with the appropriate research oversight. The much more common scenario for most practicing surgeons is the adoption of a technique that has been thought of by another surgeon who has subsequently studied it and reported on the outcomes. In such a scenario, if any surgeon is considering adopting this approach, then he or she must consider a number of important ethical issues. It is this last, and most common, scenario that we will focus our attention in the following pages.

Early Adoption of Novel Surgical Techniques This discussion is obviously taking place in a volume devoted to transoral endocrine surgery and thus will be focused primarily on the specific issues that may arise in this type of surgical approach. However, it is valuable to note that the ethical issues raised are similar for every situation in which a surgeon is adopting a technique that was not part of the surgeon’s original training. Thus, the ethical issues of early adoption of novel surgical approaches are actually relevant to the continuous adoption of new techniques throughout a surgeon’s career. The procedures that we may have learned as residents and fellows are part of the background knowledge that each surgeon has when applying for privileges at a hospital. For example, consider the case of Dr. Anne Smith. As a recent graduate from an endocrine surgery fellowship, Dr. Smith has participated in many thyroidectomies. She has applied for, and has obtained, hospital privileges that are commensurate with her education, training, and experience. She has recently seen presentations on a new transoral approach to thyroidectomy and has reviewed several publications that reported on the experience of groups in both the United States and abroad. She has decided that this is a technique that she wants to be able to offer to her patients, when appropriate. She now must navigate the steps in order to safely bring this technique into her surgical repertoire and offer to patients in an ethical fashion. Preparation of the Surgeon for Adoption of Novel Techniques The first thing that Dr. Smith must do is consider whether her prior education, surgical training, or prior experience has adequately equipped her to adopt this new technique. This is a level of introspection into her own skills and experience that must be done in a very honest fashion before embarking on any novel surgical technique [2]. Just because there are reports of expert surgeons in specialized centers safely performing the new operation, it does not necessarily follow that Dr. Smith can or should be offering it.

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For example, a surgeon must consider what operative skills he or she possesses that would be transferable to the new technique. In the case of transoral t­ hyroidectomy, the technique utilized by most surgeons at the present time is an endoscopic procedure utilizing a rigid scope and rigid instruments. In this context, if Dr. Smith has no rigid endoscopic or laparoscopic skills from other operations, then a necessary first step will be acquiring such a skill set. Similarly, if Dr. Smith had not actually had much training or experience in thyroid surgery, but was very experienced in laparoscopic surgery, she should acquire the necessary skills and experience in thyroid surgery prior to attempting to learn transoral thyroidectomy techniques. If the answer to the first question, “Do I have the appropriate background training and experience that would be transferable to this new operation?” is “yes,” then Dr. Smith must set about obtaining the specific skills necessary for the new operation [3]. There are several ways to acquire such skills. Dr. Smith can spend time reviewing videos of the operation. Today, there are often many high-quality videos available online to learn new techniques. However, surgeons must realize that most online videos have been edited to point out the important portions of the operation and rarely contain footage of the challenging pitfalls that may have occurred early in a surgeon’s experience. In addition to watching videos, it is critically important for Dr. Smith to actually see the operation in person. This should ideally be done with an experienced surgeon and should be a true educational experience rather than simply stopping by an operating room for a portion of the new procedure. In order for this to be a worthwhile experience, Dr. Smith should ideally see several cases of the new operation so that she can truly appreciate the complexities that different patients and different clinical indications for surgery might offer. It is essential that when considering whether to adopt this new technique, Dr. Smith plans for the time commitment necessary to work with other surgeons who already have experience with the new technique. Cadaver labs can be important in gaining the experience with the novel operation. Without question, performing an operation on a cadaver is an expensive proposition, but compared with the potential risks to an individual patient of an unskilled surgeon performing an operation, the costs are trivial. Cadaver labs may be undertaken individually at the surgeon’s own institution or in the context of a course specifically designed to teach the operation. The advantage of a cadaver lab that is part of a larger course is that the learning participants are able to practice with the cadaver while under the guidance of an expert. Fortunately, there are courses such as these available both in the United States and abroad for transoral endocrine surgery. If it is possible to practice the novel technique in a simulated fashion, then the monetary costs of obtaining cadavers to practice on can potentially be reduced. Unfortunately, high-fidelity simulators are not easy to obtain and are rarely available for relatively new operations. A combination of the above options is likely best for most surgeons, but individual decisions must be made by each surgeon about how to acquire the necessary skill set. Additionally, surgeons must be appropriately circumspect about their skills to allow the necessary time for appropriate training to occur.

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Appropriate Hospital Privileges Once Dr. Smith has acquired the necessary skills to safely offer the operation to her patients, it is important to ensure that she has approval from her hospital to proceed. Depending on the novelty of the procedure, there may be special credentialing that the hospital requires before offering the novel operation to patients. In most circumstances, if Dr. Smith’s original credentials included similar procedures with readily transferable surgical skills to the new operation, then the original privileges will likely be sufficient. However, it is important to be proactive to determine if additional privileges are necessary before offering the new procedure. Once there is hospital approval for the new procedure, whether required by the credentials committee or not, Dr. Smith should consider identifying an appropriately experienced surgeon who can travel to her hospital as a proctor for at least several of the new operations. Whether a proctor is necessary and for how many cases a proctor may be beneficial is dependent on the procedure and also on the surgeon. Such proctoring arrangements should be carefully considered. There is no standard for what the proctor’s role will encompass and what responsibilities the proctor will have for the operation. Questions about hospital privileges and malpractice coverage for the proctor should be settled before a proctor is invited to an institution. If there will be a proctor present in the operating room, this arrangement should be clearly disclosed to patients. However, it is also important that patients not be misled about the level of involvement the proctor will have. Will the proctor be allowed to scrub on the case or simply offer advice? Such issues must be sorted out ahead of time so that patients are not misled and so that both the proctor and the operating surgeon have appropriate expectations of what will occur in the operating room.

Assembling the Team Not only is it essential for Dr. Smith to acquire the skill set to safely offer this new operation, but it is also essential that the rest of the operating room team is also appropriately trained. There may be specific anesthetic issues about the intubation or the patient positioning that require careful forethought. Thus, the anesthesiologist who will be involved in the early cases should be brought into the training early on. The scrub nurse/technician and the circulating nurse in the operating room should be fully versed in the new equipment, if any, that might be needed. If there are different scopes or devices that will be used for the new operation, it is imperative that there has been appropriate training so that patients are not put at increased risk. With new devices, there may be a representative from the manufacturer who is planning on being in the operating room to provide assistance, but surgeons must ­acknowledge that depending on such industry representatives in the operating room as the only education of staff is inadequate.

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Once the anesthesia and operative team are assembled, it is often valuable to go through a trial run of the operation even before the first patient is ever scheduled to ensure that all members of the team are fully comfortable with the steps of the operation and the differences from the conventional approach. This is also a good time to set appropriate expectations about how long the operation is likely to take in the early cases and to schedule appropriately. It should be self-evident, but novel surgical procedures very often take much longer than the conventional approach and should be scheduled accordingly. For example, if Dr. Smith is generally comfortable with scheduling 3–4 thyroidectomies in a single day in the operating room, she should not assume that she can schedule the same number of transoral cases in a day. It is often best to overestimate the time that the new procedure will take to ensure that cases after the new operation are not unreasonably delayed due to overly ambitious scheduling.

Discussion with Patients Once all the above steps have been taken, it is finally time to begin having discussions with patients about the new operation. This is the essential informed consent process. The most important aspect of communicating with patients about a new procedure is for the surgeon to be very honest about his or her experience with the patient. This is not only essential from an ethical perspective, but it is also critical to lessen the risk of malpractice litigation should the patient suffer any complications from the new procedure. Although tempting, surgeons must withstand the temptation to use euphemisms when discussing one’s experience. It means a very different thing to most patients to hear their surgeon say, “I have a small experience with transoral thyroidectomy” instead of “You will be my first patient to have a transoral thyroidectomy.” In order for patients to make informed decisions about whether to proceed with the new operation, they must understand what the surgeon’s actual experience is. At some point, it is no longer necessary to say exactly how many of the new operation the surgeon has done, but usually that is only after gaining significant experience. All surgeons know that the “learning curve” exists and that it is different for every surgeon and every new operation. Thus, informing the patient of one’s actual experience is critical. Although many surgeons are hesitant to be so upfront with patients about their lack of experience with a new procedure, this is where the previous training becomes important to be able to share with the patient. Most patients recognize that a surgeon will have less experience with a new operation than the conventional one, but for the appropriately motivated patient, the benefits of the new operation will outweigh the experience differential. In the context of transoral thyroidectomy, if a patient is sufficiently motivated to avoid a visible scar in the neck, then the surgeon’s lack of experience with transoral thyroidectomy may be less important. Surgeons should also be circumspect about which patients are offered the new operation early in one’s experience. For example, although the most experienced

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surgeons with transoral thyroidectomy are safely performing total thyroidectomies for Graves’ disease, such patients are not the best patients with which to begin one’s experience. In the case of transoral thyroidectomy, the best patients early in one’s experience will be those with relatively small thyroid nodules who only need a lobectomy. As one gains experience with the more straightforward cases, only then is it appropriate to offer the procedure in more challenging cases. It is important that in the informed consent process, the surgeon clearly communicates what the benefits of the new operation are. Some patients may be drawn to a new procedure solely because it is new even when the benefits are unclear. Similarly, surgeons must fully disclose the uncertainties that may exist about the risks of a new operation. Disclosure of risks is essential to informed consent in surgery, but often there is uncertainty about what the true risks of a new procedure may be. In the context of transoral thyroidectomy, the risks of recurrent laryngeal nerve injury and hypoparathyroidism are unlikely to be lower than with conventional surgery. However, it will only become apparent after many cases have been performed if these small risks are significantly increased, the same, or decreased with the new operation. It should go without saying that surgeons should develop the skill and expertise with a new operation before widely marketing the operation to patients. Unfortunately, in the current era of bitter competition in health care, surgeons often have to be proactive in preventing widespread marketing before there is appropriate experience and expertise. To suggest that a “new” operation is “new and improved” is unethical if there is no data to support this claim. This is important in the context of transoral endocrine surgery because at the time of writing of this chapter the only benefit that the new operation affords is lack of a visible scar. There are currently no data showing that the operation has any other benefit. Surgeons must be up front with their patients about this fact.

Conclusions It is essential for the well-being of patients that surgeons be able to learn new techniques and integrate novel procedures into their practices. However, there are multiple ethical challenges to learning a new operation and offering it safely to patients. Essential to all of the steps noted above is the importance of honesty. The surgeon must be honest with him or herself about what skill set is possessed and what training is necessary before offering a new operation to patients. The surgeon must also be honest with patients about the experience that he or she has with the new procedure so that patients can make truly informed decisions about whether to proceed with the new operation. Patient safety must be the primary concern as every surgeon evaluates how to integrate new operations into one’s practice.

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References 1. Biffl WL, Spain DA, Reitsma AM, Minter RM, Upperman J, Wilson M, et  al. Responsible development and application of surgical innovations: a position statement of the Society of University Surgeons. J Amer Coll Surg. 2008;206:1204–9. 2. Angelos P.  The ethical challenges of surgical innovation for patient care. Lancet. 2010;376:1046–7. 3. Russell JO, Anuwong A, Dionigi G, Inabnet WB 3rd, Kim HY, Randolph G, Richmon JD, Tufano RP.  Transoral thyroid and parathyroid surgery vestibular approach: a framework for assessment and safe exploration. Thyroid. 2018;28(7):825–9.

Chapter 3

Alternative Remote Access Approaches to Endocrine and Neck Surgery Meghan E. Garstka, David J. Terris, and Emad Kandil

Introduction The conventional surgical approach to thyroid or parathyroid surgery utilizes an anterior neck incision 5–8  cm in length. This anterior incision is undesirable for many patients, especially young patients or patients with a history of healing with keloid or hypertrophic scars. Clinicians tend to score scar cosmesis higher than patients, and 75% of patients undergoing traditional cervical approaches expressed a clear preference for an extracervical, “scarless in the neck” approach if available [1]. Such techniques have become available due to advances in surgical technology and, in particular, the application of the novel robotic-assisted approaches. Minimally invasive video-assisted endoscopic thyroidectomy (MIVAT) was developed and reported by Miccoli et al. in the early 2000s [2] and initially gained significant interest in the United States [3–5].Simultaneously, various groups experimented with remote access techniques that utilized endoscopic technology and relocated incisions from the neck to the anterior chest, breast, or axilla, but these techniques were often limited by two-dimensional endoscopic visualization and rigid endoscopic instruments [6].The application of robotic-assisted technology, in particular through the transaxillary approach as introduced by Chung, and the facelift or retroauricular approach as introduced by Terris provided threedimensional visualization with a stable platform and multiarticulated endoscopic arms, which proved ideal for the limited workspace available in the neck [7–9]. In

M. E. Garstka (*) · E. Kandil Department of Surgery, Tulane University School of Medicine, New Orleans, LA, USA e-mail: [email protected]; [email protected] D. J. Terris Augusta University Thyroid and Parathyroid Center, Department of Otolaryngology – Head & Neck Surgery, Augusta University, Augusta, GA, USA © Springer Nature Switzerland AG 2020 J. O. Russell et al. (eds.), Transoral Neck Surgery, https://doi.org/10.1007/978-3-030-30722-6_3

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response to the large number of techniques developed for remote access thyroid surgery, the American Thyroid Association (ATA) issued a statement on this topic in 2016 with discussion of four most commonly utilized procedures: the endoscopic breast approach, the endoscopic and robotic bilateral axillo-breast approach (BABA), the endoscopic and robotic axillary approach, and the endoscopic and robotic facelift (retroauricular) approach [10]. This statement acknowledged that remote access thyroid surgery has a role when performed by experienced surgeons in select circumstances and recommended that adherence to strict selection criteria defined by ongoing quality outcomes research be used to choose the surgical approach appropriate for a given patient. The two remote access techniques used most commonly in the United States for thyroidectomy and parathyroidectomy are the robotic gasless transaxillary and retroauricular approaches [6, 7, 11–13]. This chapter will discuss these two approaches in detail.

Patient Selection Patients best suited to both the robotic-assisted gasless transaxillary and retroauricular remote access techniques for thyroid and parathyroid surgery are typically young, are female, and have small or average body mass indices (BMIs) less than 30 kg/m2. These techniques may be considered especially in patients who fit these criteria with a history of keloid or hypertrophic scar formation. Older or obese patients may undergo these procedures safely by experienced surgeons, but it is recommended that the surgeon new to these techniques begin with conservative patient selection due to the associated learning curve. For the transaxillary approach, patients also must not have anatomic or pathologic contraindications to the required procedural positioning, such as rotator cuff pathology or cervical spine stenosis. Patients undergoing these robotic-assisted remote access procedures should be counseled preoperatively as to the possible need for conversion to a standard open cervical procedure, should it become necessary during the course of the operation. Recent studies of these remote access approaches have reported success in total thyroidectomy and neck dissection [14, 15]; however, due to the learning curve, partial thyroidectomy is recommended as the initial procedure for surgeons incorporating this technique into practice. Historically, relative clinical contraindications to robotic thyroidectomy have included nodules greater than 5  cm, large goiters with volumes greater than 40  mL, known T2 well-differentiated thyroid cancer, Hashimoto’s thyroiditis, and Graves’ disease, as well as a history of previous neck surgery or radiation [16]. However, recent studies have demonstrated the safety and feasibility of robotic-assisted remote access approaches for patients with Graves’ disease and advanced thyroid cancer [14, 15, 17–20]. Absolute clinical contraindications to robotic thyroidectomy have included large substernal or retropharyngeal goiters, T3 thyroid cancer or any suspicious gross invasion, and medullary thyroid cancer. Current and future studies on short- and long-term clinical outcomes at

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large-volume institutions will help to further define the appropriate indications and contraindications for robotic-assisted remote access procedures. Additionally, for parathyroidectomy, patients with a well-localized disease are considered appropriate for robotic-assisted remote access procedures, while those with multiglandular or poorly localized disease requiring possible bilateral exploration or with concern for malignancy may be better suited by the conventional open cervical approach.

Surgical Approaches Robotic-Assisted Gasless Transaxillary Approach The robotic-assisted gasless transaxillary approach to thyroidectomy and parathyroidectomy was developed in Asia in the early 2000s and modified for the Western population [8, 12, 21, 22]. A dual-channel camera oriented in the 30° down position and at least three robotic instruments (Maryland dissector, ProGrasp forceps, Harmonic curved shears) are used during the robotic-assisted portion of the procedure, while creation of the transaxillary flap prior to docking requires electrocautery, a vascular DeBakey forceps, and various retractors including the Army-Navy, right-angled, and lighted breast retractors [9, 23]. The lighted breast retractor is shown in Fig. 3.1. The steps in the procedure are detailed as follows. Patient Positioning The patient is positioned supine on the operating room (OR) table and undergoes general anesthesia. Intubation with a neural integrity monitor electromyogram endotracheal tube is recommended for intraoperative nerve monitoring during Fig. 3.1  Lighted breast retractor used for flap creation

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the procedure, which is standard practice at the authors’ institutions. The neck is slightly extended with a shoulder roll, and the arm ipsilateral to the lesion or the larger lobe of the thyroid is placed cephalad and flexed above the head into what is known as modified Ikeda’s arm position. The contralateral arm is padded and tucked to the side of the patient. There is a risk of neuropraxia from this arm position, so the authors routinely use somatosensory evoked potentials (SSEP; Biotronic, Ann Arbor, MI) to monitor the median and ulnar nerve signals (Fig. 3.2). Proper padding of the arm and the patient during the positioning for the procedure is also critical. Intraoperative ultrasound after patient positioning and prior to incision can help the surgeon to further determine the exact location of the thyroid or parathyroid lesion and the location of the internal jugular vein in relationship to the glands in an anteroposterior plane. Figure 3.3 demonstrates modified Ikeda’s arm position and the performance of intraoperative ultrasound in this position.

Fig. 3.2  Somatosensory evoked potential (SSEP) monitoring devices are placed preoperatively to monitor median and ulnar nerve signals and prevent neuropraxia

Fig. 3.3  Modified Ikeda’s arm position (left) and intraoperative ultrasound (right)

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Incision and Landmarks The superior and inferior points of the axillary incision are drawn with the assistance of anatomic landmarks. To mark the inferior point of the incision, a transverse line is drawn from the sternal notch laterally to the axilla. The superior point of the incision is marked with a 60-degree oblique line from the thyrohyoid membrane to the axilla. The superior and inferior points are connected with a longitudinal mark approximately 2 inches in length running along the border of the pectoralis major muscle (Fig. 3.4). Once marked, the neck and anterior chest are prepped and draped, and the incision site is infiltrated with local anesthetic and then incised with a scalpel. Flap Creation Monopolar electrocautery is used to dissect through the subcutaneous tissues of the incision in order to expose the lateral border of the pectoralis major muscle and continues cephalad toward the clavicle in order to create a flap in the subplatysmal plane, superficial to the pectoralis fascia (Fig. 3.5). The long tip extension for the electrocautery and lighted breast retractors are used to facilitate creation of this flap until the clavicle is identified and followed medially to the sternal notch, leading to Fig. 3.4  Skin incision with inferior point drawn transversely from the sternal notch and superior point drawn oblique from the thyrohyoid membrane

Fig. 3.5  Flap creation anterior to the pectoralis major fascia

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identification of the ipsilateral sternocleidomastoid (SCM) muscle. Appropriate retraction of the skin away from the tunnel in this step is key to avoiding skin damage during dissection. The sternal (medial) and clavicular (lateral) heads of the SCM are identified. An avascular plane exists between the sternal and clavicular heads of the SCM and can be developed with electrocautery or a vessel sealer and anterior retraction of the sternal head of the SCM, exposing the omohyoid muscle (Fig. 3.6). The ipsilateral superior pole of the thyroid gland lies beneath the omohyoid muscle. Dissection of the uppermost fibers of the omohyoid muscle with electrocautery or a vessel sealer will reveal the superior pole of the thyroid gland (Fig. 3.7). The surgeon must be careful to avoid damage to the internal jugular vein during this portion of the procedure. Once the superior pole is exposed and a satisfactory exposure created in the plane between the sternal and clavicular heads, a self-­ retaining bladed robotic thyroid retractor known as the Chung retractor or modified thyroidectomy retractor (Marina Medical, Davie, FL) is mounted to the contralateral side of the operating table and used to lift the strap muscles anteriorly in order to maintain this exposure (Figs.  3.8 and 3.9). The self-retaining retractor can be connected to suction tubing to remove smoke created from sealing devices used during the procedure. Fig. 3.6  Dissection of avascular plane between the sternal and clavicular SCM heads

Fig. 3.7  Image from intraoperative video depicting dissection of the superior pedicle after exposure of the superior pole underneath the ipsilateral omohyoid muscle

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Fig. 3.8  The modified robotic thyroidectomy retractor and table attachment

Fig. 3.9  The modified robotic thyroidectomy retractor is mounted on the contralateral side of the operating table and can be hooked to suction tubing to evacuate smoke

Robot Docking The da Vinci surgical robot (Intuitive, Sunnyvale, CA) is brought into the operative field from the contralateral side of the table. Four arms are inserted through the axillary incision with the assistance of the dual-channel camera configured in the “30° down” mode, which is docked first in the central position (Fig. 3.10). A second and third arm are placed with instruments to the right or the left of the central

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Fig. 3.10  Docking of robot, with the endoscope centrally located

Fig. 3.11 Artist’s rendering of transaxillary robotic arm placement in relation to procedural landmarks

Arm #1 Camera Arm #2 Arm #3

Arm #3

camera arm under direct visualization (Fig.  3.11). Although the authors place a sealing device in the arm on the surgeon’s dominant side and a Maryland dissector in the contralateral arm, surgeons can vary instrument position with increasing experience. With a fourth arm, the Prograsper can be placed on the upper edge of the incision, to the same side of the lesion in relation to the blade of the self-retaining retractor. A laparoscopic suction/irrigation device is also inserted through the axillary incision by the assisting surgeon at the bedside. This is used for suction and irrigation and also to retract the clavicular SCM head or trachea downward during the dissection. The assistant is also responsible for placement of the nerve monitoring device and can troubleshoot robotic arm positioning and maintenance of the camera and instruments. Console Time Upon exposure of the carotid sheath prior to additional thyroid or parathyroid dissection, the vagus nerve is stimulated with the nerve monitor probe. If a bilateral dissection or neck dissection is planned, an electrode may be placed

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on the vagus nerve for continuous nerve monitoring. For thyroidectomy, the upper pole of the thyroid is retracted medially and inferiorly, and the superior thyroid vessels are dissected and divided close to the thyroid to avoid injury to the external branch of the superior laryngeal nerve. The superior pole is freed from the cricothyroid muscle, and the superior parathyroid gland is identified and preserved. The thyroid is next retracted medially, and the middle thyroid vein is dissected and divided. The recurrent laryngeal nerve is identified at the tracheoesophageal groove and is carefully followed until insertion into the cricothyroid muscle. On the right side, the surgeon must be aware of the possibility of a nonrecurrent laryngeal nerve, although short latency from vagal nerve stimulation may help to predict this finding. The functional integrity of the recurrent laryngeal nerve once identified is confirmed with the nerve monitor probe. We routinely stimulate the vagus nerve in the carotid sheath. Attention is next directed to the inferior pedicle, which is dissected and divided; the inferior parathyroid is identified and preserved. The inferior thyroid is dissected medially to the recurrent laryngeal nerve and is shaved from the trachea until reaching the contralateral side. The thyroid lobe and isthmus are divided and the specimen is extracted. This concludes the standard lobectomy dissection. If a central lymph node dissection is incorporated into the procedure, the central lymph nodes are dissected en bloc circumferentially from the nerve and removed en bloc with the thymus and the thyroid. For total thyroidectomy, once the ipsilateral lobe has been removed, subcapsular dissection of the contralateral lobe from the trachea is ­performed, until the contralateral tracheoesophageal groove is reached, where the recurrent laryngeal nerve is identified and stimulated. The superior and inferior pedicles are dissected and ligated, the recurrent laryngeal nerve is traced to the cricothyroid membrane, and the remaining thyroid is dissected and extracted through the axillary incision. The contralateral superior and inferior parathyroids are identified and preserved in the course of this dissection as well. Final stimulation of the recurrent laryngeal and vagus nerves is performed, and hemostasis is ensured. A drain is placed and the axillary incision is closed in two layers with interrupted subcutaneous and continuous subcuticular closure, which heals well and minimizes the appearance of the axillary scar (Fig. 3.12). The drain will be removed at the patient’s postoperative clinic visit. Parathyroidectomy follows similar principles but with identification, dissection, and removal of the pathologic gland and intraoperative PTH monitoring.

Robotic-Assisted Retroauricular (Facelift) Approach The robotic-assisted gasless retroauricular approach was first reported in 2011 and uses the “facelift incision” usually utilized in parotid surgeries. Patient positioning is easier in this approach and eliminates the risk of brachial plexopathy. There is also a shorter dissection distance to reach the glands in the neck from the remote incision [9, 24].

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Fig. 3.12  Appearance of transaxillary incision at postoperative clinic visit

Patient Positioning The patient undergoes general anesthesia and is intubated with an electromyography (EMG) endotracheal tube for intraoperative recurrent laryngeal nerve monitoring and is positioned supine with arms tucked bilaterally on the operating table. The head is rotated slightly 20°–30° to the contralateral side of the planned incision. The hair at the base of the occipital hairline is shaved 1 cm posteriorly along the planned incision site. The operating table is rotated 180° to allow for additional steps in the procedure. Incision and Landmarks The inferior end of the incision is marked at the inferior extent of the lobule in the postauricular crease [6, 24]. The incision is carried superiorly and posteriorly into the shaved region of the occipital hairline in a gentle curve (Fig. 3.13). The incision is infiltrated with local anesthetic and the neck is prepped and draped in a sterile fashion.

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Fig. 3.13 Preoperative marking of retroauricular incision

Flap Creation The skin is incised with a scalpel and electrocautery used to develop a subplatysmal flap, exposing the SCM muscle. The authors also have created the flap superficial to the platysma with a special Metzenbaum scissor as is done by plastic surgeons in facelift procedures, but there is risk for poor vascularity, especially in smokers. Once the SCM is identified, dissection continues anteriorly and inferiorly along the muscle. The great auricular nerve is identified, and dissection superior to this reveals the external jugular vein and the anterior border of the SCM.  If necessary for exposure, the external jugular vein can be divided. Dissection continues down to the anteromedial border of the SCM to the clavicle. The bed can be placed in reverse Trendelenburg position and rotated away from the surgeon for better exposure if needed. Dissection defines a muscular triangle bordered by the SCM, the omohyoid, and the sternohyoid muscles. The omohyoid, sternohyoid, and sternothyroid muscles are retracted ventrally, exposing the ipsilateral superior pole of the thyroid gland. The strap muscles are elevated off the thyroid lobe and the superior pedicle is isolated. At this point in the procedure, the self-retaining modified thyroidectomy or Chung retractor is secured on the contralateral side of the operating table and positioned to retract the strap muscles ventrally. A Singer hook (Medtronic, Jacksonville, FL) or Army-Navy retractor is attached to a Greenberg retractor (Codman & Shurtleff, Inc., Raynham, MA) and secured to the ipsilateral side of the operating table and serves to retract the SCM laterally and dorsally. A modified approach creates the plane between the two heads of the SCM similar to the previously described transaxillary approach and eliminates the need for the selfretaining retractor for SCM posterior retraction.

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Robot Docking The da Vinci robot system is positioned in the operative field on the contralateral side of the patient. The endoscopic camera in the “30-degree down” configuration is introduced first into the incision along the long access of the modified Chung retractor. A vessel sealer device and a Maryland grasper are placed in arms two and three and brought into the operative field under direct visualization. The vessel sealer is usually placed in the surgeon’s dominant arm, although this may be adjusted for surgeon preference. Console Time The upper thyroid pole is retracted ventrally and inferiorly and the superior thyroid vessels are dissected and divided near the capsule. The gland is then retracted medially, allowing for identification of the recurrent laryngeal nerve in the tracheoesophageal groove. The nerve monitor is used to confirm integrity of the nerve, which is dissected along its path until the insertion into the cricothyroid muscle. The superior and inferior parathyroid glands are identified and preserved. The inferior thyroid pedicle is then dissected and divided, and the thyroid is dissected from the trachea. The isthmus is divided and the thyroid is removed through the retroauricular incision. The operative steps for parathyroidectomy are similar, but only the pathologic parathyroid gland is removed with intraoperative PTH monitoring used to assess for an appropriate drop in the PTH level. Integrity of the recurrent laryngeal nerve and hemostasis is verified. Some surgeons elect to place a drain; if this is done, it is placed posterior to the retroauricular incision and removed at the postoperative clinic visit. The incision is closed in two layers. Interrupted absorbable subdermal sutures are placed first in the wound. The skin is closed with interrupted or running absorbable sutures or nonabsorbable interrupted sutures which must be removed in the clinic (Fig.  3.14). In appropriate patients, excision of redundant skin can be performed prior to closure, allowing for a simultaneous “facelift” procedure. Fig. 3.14 Postoperative appearance of retroauricular incision. Sutures and drain are in place and will be removed at the postoperative clinic visit

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Conclusion When a new technique is introduced to surgery, it is necessary to define indications for use and best practices regarding the technique. Surgeons must minimize perioperative complications and assure patient safety. The two alternative robotic-assisted remote access techniques detailed in this chapter have been discussed in reports of series of increasing volumes in the literature. However, it should be noted that although there was an initial increase in the volume of robotic thyroidectomies performed in the United States between 2009 and 2011, there was a subsequent change in trajectory in procedure volume after the Intuitive Surgical Inc., the manufacturer of the da Vinci surgical system, changed support and training policies for these procedures in October 2011 [25]. Lower-volume centers perform the majority of robotic thyroidectomies in the United States and are responsible for recent increases in utilization patterns despite higher complication rates, which highlights the ­importance of increasing surgeon exposure to and experience with these techniques in order to improve procedure safety. Complications include not only those which can occur with conventional open cervical thyroidectomy, such as recurrent laryngeal nerve injury, postoperative pain, neck hematoma, wound infection, and hypocalcemia, but also those unique to the type of access technique, such as brachial plexus neuropraxia for the transaxillary technique [9]. Reported rates of transient recurrent laryngeal nerve palsies range from 1% to 3%, with around 0.3% permanent injuries; studies have shown no significant difference in the relative risk of recurrent laryngeal nerve injury between robotic and conventional open thyroidectomies. Rates of hematoma have been reported to be approximately 1%, and brachial plexus neuropraxia about 2.2%, which can be eliminated with the use of SSEP to monitor for radial, ulnar, and median nerves. Meticulous surgical technique for hemostasis and adjunct technology such as nerve monitoring of the recurrent laryngeal nerve and median and ulnar nerve somatosensory evoked potential monitoring during transaxillary surgery can be used to assist in maintenance of patient safety during these procedures. Definition of the patient population most appropriate for these procedures will continue to evolve as surgeons become increasingly familiar with this technique. Long-term studies of clinical outcomes related to the pathology for which the procedures are performed—especially for those originally thought to be contraindications—will continue to contribute to the surgical community’s understanding of the role of remote access thyroid and parathyroid surgery in the field of endocrine surgery.

References 1. Arora A, Swords C, Garas G, Chaidas K, Prichard A, Budge J, Davies DC, Tolley N. The perception of scar cosmesis following thyroid and parathyroid surgery: a prospective cohort study. Int J Surg. 2016;25:38–43.

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2. Miccoli P, Bellantone R, Mourad M, Walz M, Raffaelli M, Berti P. Minimally invasive video-­ assisted thyroidectomy: multiinstitutional experience. World J Surg. 2002;26(8):972–5. 3. Terris DJ, Gourin CG, Chin E. Minimally invasive thyroidectomy: basic and advanced techniques. Laryngoscope. 2006;116(3):350–6. 4. Duke WS, White JR, Waller JL, Terris DJ. Endoscopic thyroidectomy is safe in patients with a high body mass index. Thyroid. 2014;24(7):1146–50. 5. Duke WS, White JR, Waller JL, Terris DJ.  Six-year experience with endoscopic thyroidectomy: outcomes and safety profile. Ann Otol Rhinol Laryngol. 2015;124(11):915–20. 6. Bomeli SR, Duke WS, Terris DJ.  Robotic facelift thyroid surgery. Gland Surg. 2015;4(5):403–9. 7. Mohamed HE, Kandil E.  Robotic trans-axillary and retro-auricular thyroid surgery. J Surg Oncol. 2015;112(3):243–9. 8. Yoon JH, Park CH, Chung WY. Gasless endoscopic thyroidectomy via an axillary approach: experience of 30 cases. Surg Laparosc Endosc Percutan Tech. 2006;16(4):226–31. 9. Terris DJ, Singer MC, Seybt MW. Robotic facelift thyroidectomy: patient selection and technical considerations. Surg Laparosc Endosc Percutan Tech. 2011;21(4):237–42. 10. Berber E, Bernet V, Fahey TJ 3rd, Kebebew E, Shaha A, Stack BC Jr, Stang M, Steward DL, Terris D, American Thyroid Association Surgical Affairs Committee. American Thyroid Association statement on remote-access thyroid surgery. Thyroid. 2016;26(3):331–7. 11. Duke WS, Holsinger FC, Kandil E, Richmon JD, Singer MC, Terris DJ. Remote access robotic facelift thyroidectomy: a multi-institutional experience. World J Surg. 2017;41(1):116–21. 12. Kandil EH, Noureldine SI, Yao L, Slakey DP.  Robotic transaxillary thyroidectomy: an examination of the first one hundred cases. J Am Coll Surg. 2012;214(4):558–64; discussion 564–6. 13. Zaidi N, Daskalaki D, Quadri P, Okoh A, Giulianotti PC, Berber E.  The current status of robotic transaxillary thyroidectomy in the United States: an experience from two centers. Gland Surg. 2017;6(4):380–4. 14. Lee J, Kwon IS, Bae EH, Chung WY. Comparative analysis of oncological outcomes and quality of life after robotic versus conventional open thyroidectomy with modified radical neck dissection in patients with papillary thyroid carcinoma and lateral neck node metastases. J Clin Endocrinol Metab. 2013;98(7):2701–8. 15. Lee SG, Lee J, Kim MJ, Choi JB, Kim TH, Ban EJ, Lee CR, Kang SW, Jeong JJ, Nam KH, Jo YS, Chung WY. Long-term oncologic outcome of robotic versus open total thyroidectomy in PTC: a case-matched retrospective study. Surg Endosc. 2016 Aug;30(8):3474–9. 16. Bhatia P, Mohamed HE, Kadi A, Kandil E, Walvekar RR.  Remote access thyroid surgery. Gland Surg. 2015;4(5):376–87. 17. Kandil E, Noureldine S, Abdel Khalek M, Alrasheedi S, Aslam R, Friedlander P, Holsinger FC, Bellows CF. Initial experience using robot- assisted transaxillary thyroidectomy for Graves’ disease. J Visc Surg. 2011;148(6):e447–51. 18. Noureldine SI, Yao L, Wavekar RR, Mohamed S, Kandil E. Thyroidectomy for Graves’ disease: a feasibility study of the robotic transaxillary approach. ORL J Otorhinolaryngol Relat Spec. 2013;75(6):350–6. 19. Kang SW, Chung WY. Transaxillary single-incision robotic neck dissection for metastatic thyroid cancer. Gland Surg. 2015;4(5):388–96. 20. Noureldine SI, Jackson NR, Tufano RP, Kandil E.  A comparative North American experience of robotic thyroidectomy in a thyroid cancer population. Langenbeck's Arch Surg. 2013;398(8):1069–74. 21. Kang SW, Jeong JJ, Yun JS, Sung TY, Lee SC, Lee YS, Nam KH, Chang HS, Chung WY, Park CS. Gasless endoscopic thyroidectomy using trans-axillary approach; surgical outcome of 581 patients. Endocr J. 2009;56(3):361–9.

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22. Ryu HR, Kang SW, Lee SH, Rhee KY, Jeong JJ, Nam KH, Chung WY, Park CS. Feasibility and safety of a new robotic thyroidectomy through a gasless, transaxillary single-incision approach. J Am Coll Surg. 2010;211(3):e13–9. 23. Alzahrani HA, Mohsin K, Ali DB, Murad F, Kandil E. Gasless trans-axillary robotic thyroidectomy: the technique and evidence. Gland Surg. 2017;6(3):236–42. 24. Alabbas H, Bu Ali D, Kandil E.  Robotic retroauricular thyroid surgery. Gland Surg. 2016;5(6):603–6. 25. Hinson AM, Kandil E, O'Brien S, Spencer HJ, Bodenner DL, Hohmann SF, Stack BC Jr. Trends in robotic thyroid surgery in the United States from 2009 through 2013. Thyroid. 2015;25(8):919–26.

Chapter 4

Patient Selection for Thyroidectomy and Parathyroidectomy Using the Transoral Endoscopic Vestibular Approach Zhen Gooi and Jeremy D. Richmon

Introduction Modern conventional transcervical thyroid surgery is safe with complication rates of permanent recurrent laryngeal nerve injury and hypoparathyroidism in the low single digits [1]. Excellent reproducible outcomes have allowed surgeons to turn their focus toward improving quality-of-life considerations related to thyroid surgery. Efforts toward reducing the extent of neck scarring emerged in the 1990s with the introduction of endoscopes to allow for reduction of incision length, followed by extracervical access in the form of transaxillary, postauricular transfacial, and transareolar approaches. The transoral approach to thyroidectomy and parathyroidectomy is the most recently introduced technique and represents a paradigm shift by eliminating external skin incisions altogether [2]. Transoral endoscopic thyroidectomy vestibular approach (TOETVA) and transoral endoscopic parathyroidectomy vestibular approach (TOEPVA) are gaining in popularity, with increasing use in the Asian-Pacific region and recent adoption in some European and North American centers. The term transoral thyroid surgery, when used in this chapter, refers to the transoral endoscopic vestibular approach technique. The full technical details of this surgery are beyond the scope of this chapter; however, some will be described briefly here to frame the discussion on patient selection [3]. In the TOETVA and TOEPVA approach, three intraoral incisions are made on the inner vestibular mucosa of the lower lip and then connected with the neck by blunt dissection. CO2 gas insufflation is used to maintain the working space. A camera is Z. Gooi (*) Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Chicago, Chicago, IL, USA e-mail: [email protected] J. D. Richmon Head and Neck Surgical Oncology and Reconstructive Surgery, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA © Springer Nature Switzerland AG 2020 J. O. Russell et al. (eds.), Transoral Neck Surgery, https://doi.org/10.1007/978-3-030-30722-6_4

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placed through the larger central incision, and dissecting instruments are placed through the lateral incisions. Subplatysmal flaps are raised and the strap musculature is elevated off the thyroid lobe. The thyroid isthmus is usually divided, followed by ligation of the superior pole vascular pedicle enabling retraction of the thyroid lobe in an anteromedial direction. The recurrent laryngeal nerve is usually identified close to its cricothyroid region insertion point and traced proximally, then allowing the surgeon to free the paratracheal attachments of the thyroid. The dissected specimen is extracted through the central lip incision in an endoscopic specimen bag, followed by reapproximation of the strap muscles and closure of the lip incisions.

Challenges Associated with TOETVA and TOEPVA When taking the initiative toward performing transoral thyroid surgery, the surgeon should be aware of various challenges and frame initial patient selection to mitigate these issues. One can think of potential challenges for this approach according to the following categories: 1. The oral cavity – This anatomical region is not routinely encountered in the routine practice of most general surgeons and therefore may involve unfamiliar anatomy. It is not a sterile environment and theoretical risk of contamination of the neck space exists. Placement of an intraoral endotracheal tube can crowd the surgical field, while transnasal intubation techniques may not be routinely practiced by some anesthesiologists. 2. The thyroid – A variety of disease processes can affect the vascularity, firmness, and adherence of the thyroid gland to its surrounding fascial planes. This has a direct impact on the ability of the surgeon to grasp, retract, and dissect surrounding tissue and the thyroid gland while working within a confined space, all the while preserving hemostasis and identifying key structures. Secondly, the typical central vestibular incision places a limit on the size of the gland that can be removed en bloc through it. This is a key consideration for thyroid cancer. 3. Other patient and logistical factors – The prime motivation for a patient to pursue the transoral approach is avoidance of a visible scar. While mostly short-term, this procedure has its own cosmetic and procedural drawbacks, among them possible ecchymosis, and varying degrees of chin, lower lip, and submental skin numbness. The likelihood and degree of these procedural drawbacks are related to the length of surgical dissection time and dissection techniques, which has a close relationship with overall surgeon familiarity with this procedure. Certain neck and jaw cephalometric features can affect the maneuverability of instruments within the working space for dissection. The procedure also requires familiarity with laparoscopic surgical techniques and CO2 gas insufflation, a skill set that is not always part of routine surgical training. Differences in haptic feedback, limited working room for surgical instruments, maintaining hemostasis, and clear visualization of the operative field present new challenges for the

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s­urgeon unfamiliar with these principles. The principle of triangulation, i.e., accounting for the trajectory of instrument placement to allow adequate traction and counter-traction and to permit a two-handed dissection, may also be foreign to some surgeons. Finally, the interested surgeon will also have to address local, regional, institutional, and collegial biases which favor traditional thyroid surgery or more established remote-access procedures. In this endeavor, it is critical for the surgeons to demonstrate comparable outcomes to conventional thyroid surgery with their initial transoral procedures to overcome this barrier.

Learning from Patient Selection in Pioneering Centers It is worth examining the initial series of patients performed by Anuwong in Police General Hospital, Bangkok, to better characterize how beginning surgeons should select their patients. He is widely regarded to be one of the earliest adopters of transoral thyroid surgery and currently has the largest experience in the world [4]. In their initial series of 60 patients operated on from April 2014 to January 2015, women accounted for 95% of patients with a mean age of 41 years [2]. Most patients (57%) had a single-thyroid nodule and were treated with hemithyroidectomy and isthmusectomy. A total of 43% of patients received total thyroidectomy, the vast majority of whom had multinodular goiters. Two patients had papillary microcarcinomas. The average nodule size for the entire series was 5.4 cm. Median operative time for patients receiving hemithyroidectomy was 90 minutes (range, 75–180 minutes), while it was 135.5 minutes (range, 105–300 minutes) in those receiving total thyroidectomy. The incidence of transient hypoparathyroidism and recurrent laryngeal nerve injury was 5% and 3.3%, respectively, while there were no instances of permanent hypoparathyroidism or recurrent laryngeal nerve injury. There were no wound infections and patients were treated with 7 days of perioperative antibiotics. In an expanded case series incorporating 425 patients with similar inclusion criteria operated until August 2016, the group reported similar outcomes with regard to operative time and operative complications [4]. This expanded case series reports on three patients requiring conversions to open thyroidectomy because of excessive blood loss. Two of these patients had Graves’ disease, while the remaining patient had a thyroid goiter with a maximal dimension in excess of 12 cm. A group from Xiamen, China, described their initial case series of transoral thyroid surgery of 81 patients from 2011 to 2015 [5]. All patients had preoperative ultrasound with the most common finding being unilateral nodules with benign features and an average diameter of 3.4  cm in 65 patients. All 65 patients received thyroid lobectomy. The group utilized intraoperative frozen section analysis of the excised thyroid specimens, and unilateral papillary thyroid cancer was found in five patients, with an average diameter of 3.8 cm. Two patients in this case series required conversion to open thyroidectomy because of intraoperative air embolism. It is

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unclear what anatomical/surgical interventions contributed to this complication. The group described an average operative duration for unilateral thyroidectomy of 90 minutes with an average estimated blood loss of 26 mL. No instances of recurrent laryngeal nerve palsy or hypoparathyroidism were reported. Within North America, Russell et al. reported on a multi-institutional combined cohort of 216 patients who received remote-access approaches (RAA) for thyroidectomies. In this cohort, 92 had the TOETVA approach [6]. For the combined cohort, there was no significant difference in size of the index nodule between a pooled cohort of patients undergoing conventional transcervical approaches (2.8 ± 1.6 cm vs. 2.9 ± 1.9 cm). There were no instances of recurrent laryngeal nerve injury in the RAA cohort, although it was noted that median operative time was longer in the RAA cohort in a statistically significant manner.

 urrent Indications and Contraindications for Transoral C Thyroid Surgery As with any new procedure in the early stages of development and adoption, the indications and contraindications for transoral thyroid surgery are in evolution from the most conservative cases to more advanced diseases by various centers and authors as experience is accumulated. The prime indication for transoral thyroid surgery is a very strong patient preference to avoid a visible scar. A study group convened at the first International Transoral Thyroidectomy NOTES Conference in Bangkok, Thailand (February 2016), and published their recommendations for inclusion criteria for transoral thyroid surgery to encompass thyroid lobe size less than 10  cm, benign tumors, follicular neoplasm, papillary microcarcinoma, and Graves’ disease [7]. It is worth noting that reported conversions to open surgical procedures in the literature have been attributed to either substernal goiters or Graves’ disease. Bearing this in mind, and considering data from published studies, Razavi and Russell have proposed contraindications for transoral thyroid surgery to include a prior history of head and neck surgery, head/neck/upper mediastinal irradiation, active clinical hyperthyroidism, preoperative recurrent laryngeal nerve palsy, lymph node metastasis, extrathyroidal extension of tumor, oral abscesses, and substernal thyroid extension [8].

How Should Surgeons Select Patients? Given the indications, contraindications, and challenges to transoral thyroid surgery highlighted above, we recommend the following selection criteria for surgeons unfamiliar with the transoral technique in order to enhance likelihood of success:

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1. Patient motivation – The ideal patient should have a very strong motivation to avoid external neck incisions and at the same time understand the risk of bruising, numbness and paresthesia to the lip and chin, and sensation over the central neck that may occur. Current data demonstrate that the primary benefit of this technique is cosmetic, and the patient should understand that this technique does not equate to a lower-risk or minimally invasive approach. Preoperative counseling and the informed decision-making process should include disclosure on the part of the surgeon regarding the higher likelihood of longer operative time, potential for conversion to open thyroid surgery, and rare complications including mental nerve injury and air embolism. 2. Patient past medical history – Patients with a prior history of neck surgery and irradiation should be excluded. Hashimoto’s thyroiditis can make the thyroid gland more adherent to surrounding tissue planes and lead to increased difficulty with dissection for the beginning surgeon. The hypervascularity associated with Graves’ disease also increases the risk of intraoperative bleeding during dissection limiting visualization of the operative field. It is recommended that the beginning surgeon should therefore exclude patients with a prior history of these conditions from their initial cases. 3. The oral cavity, neck anatomic features, and thyroid gland – Men are not ideal initial patients for this surgery early in one’s experience as the more prominent chin and thyroid notch limit maneuverability of instruments and retraction of the dissected portions of the thyroid. The presence of oral cavity braces decreases the space for camera and instrument placement and increases difficulty of specimen extraction but is not an absolute contraindication. Mandibular prognathism or orthognathism is an additional anatomic feature worth evaluating preoperatively. During extraction of the thyroid specimen, the surgeon must negotiate the curvature of the submental space and bony projection of the mandibular symphysis. The abovementioned anatomic features will add to the complexity of this endeavor. Smaller female patients therefore have more favorable anatomy to hone early experience. Preoperative workup should include at least a neck and thyroid ultrasound. Consideration should be given to obtaining a computed tomography (CT) scan to identify any retroesophageal and substernal extension of the thyroid, which are excluding criteria. Fine-needle aspiration of thyroid nodules is imperative. Given concerns for oncologic safety, we recommend that initial surgical cases should not include patients with Bethesda classification V or VI or if preoperative ultrasound shows evidence of central or lateral neck metastasis. Oncologic resections and neck dissections should be reserved for the experienced transoral surgeon who has already summited the learning curve. We propose that maximal thyroid dimension should be 6 cm or less in length with a maximal nodule dimension of 4 cm or less for beginning surgeons. One additional consideration is thyroid nodule location and side. An optimal location for thyroid nodules for the beginning surgeon is the mid or lower pole, especially in an anterior location. As the initial portion of the surgery

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focuses on the upper pole, and identification of the recurrent laryngeal nerve ­typically occurs in a more proximal location close to its cricothyroid insertion point compared to traditional open thyroid surgery, a prominent upper pole nodule or midposterior nodule can present additional difficulty for the beginning surgeon. Similarly, a prominent isthmus nodule can also increase the complexity of dissection, as the isthmus is typically divided early on during the procedure to allow for retraction of the thyroid gland for superior pole dissection. We recommend that the beginning surgeon consider selection of patients who require thyroid lobectomy or who have thyroid nodules on the same side as the surgeon’s dominant hand. Dissection with the laparoscopic instruments is significantly easier when the planned thyroid lobe excision/thyroid nodule is on the surgeon’s dominant side, at least during the earliest cases. Finally, given the expected increased length of time for surgical dissection, the beginning surgeon should consider confining initial patient selection to those who only require thyroid lobectomies. The summary for recommended patient selection criteria is displayed in Table 4.1. 4. Transoral parathyroidectomy for initial surgical cases – The literature does not contain a large body of evidence for transoral parathyroidectomies, and this is largely reflective of the epidemiology of parathyroid disease in East Asia, with thyroid disease predominating. Anuwong’s group reported on a series of 12 patients treated from 2015 to 2016. Six had primary hyperparathyroidism with single parathyroid adenomas, and the other six had secondary hyperparathyroidism who received four-gland parathyroid excision and autotransplantation [9]. Biochemical cure was achieved in all patients, with mean operative time in patients with primary hyperparathyroidism being 108 minutes and 186 minutes in the cohort of patients with secondary hyperparathyroidism. There was one instance of transient recurrent laryngeal nerve injury. The principles for port placement, surgical exposure of the operative field, and specimen extraction are similar for transoral thyroid and parathyroid surgery with the exception that Table 4.1  Patient selection criteria for the beginning surgeon Factor Patient motivation Past medical history Anatomic factors

Ideal patient selection criteria Patient understands and accepts likelihood of bruising, lip and cutaneous numbness, longer operative time, and possible requirement for conversion to open surgery No history of Graves’ disease/Hashimoto’s thyroiditis Oral cavity – absence of braces/dental devices, retrognathia Female gender Thyroid nodule ≤4 cm in size, thyroid lobe ≤6 m in size Bethesda classification of thyroid nodule II–IV No retrosternal/retroesophageal thyroid extension Middle/lower pole location of thyroid nodule Thyroid lobe/nodule location on ipsilateral side of the dominant hand of the surgeon

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there is no routine transection of the isthmus or takedown of the superior pole of the thyroid, although the latter may be necessary with superior glands. The magnified view conferred by endoscopes may be advantageous in identifying parathyroid adenoma candidates. Patients who would be ideal candidates for beginning surgeons considering transoral parathyroid surgery are those with biochemically confirmed primary hyperparathyroidism meeting criteria for surgery and a localized single adenoma within the neck based on imaging and nuclear medicine studies. Cross-sectional imaging should be considered for the beginning surgeon to verify that the adenoma is not in an atypical location. An inferior parathyroid adenoma may confer increased ease of dissection for the beginning surgeon, given its location ventral to the recurrent laryngeal nerve.

Future Directions Reflective of all new surgical endeavors, the learning curve for skill acquisition in this procedure requires further study but anecdotally is quite steep [10]. One surrogate measure of surgical skill is operative time, and beginning surgeons should be meticulous in documenting their times and outcomes. This should be correlated with thyroid dimensions, patient anatomic features and outcome measures for quality of life, dermatologic assessments of degree of bruising, recurrent laryngeal nerve function, hypocalcemia, and lip/chin/neck paresthesia. Reporting on these data points will further assist in defining optimal patient selection criteria for the beginning surgeon. Editor’s note: The list of indications and contraindications is always in flux with novel techniques. The reader is advised to stay abreast of the most recent literature when considering the application of transoral surgery.

References 1. Rosato L, Avenia N, Bernante P, De Palma M, Gulino G, Nasi PG, et al. Complications of thyroid surgery: analysis of a multicentric study on 14,934 patients operated on in Italy over 5 years. World J Surg. 2004;28(3):271–6. 2. Anuwong A. Transoral endoscopic thyroidectomy vestibular approach: a series of the first 60 human cases. World J Surg. 2016;40(3):491–7. 3. Russell JO, Anuwong A, Dionigi G, Inabnet WB 3rd, Kim HY, Randolph G, et al. Transoral thyroid and parathyroid surgery vestibular approach: a framework for assessment and safe exploration. Thyroid. 2018;28(7):825–9. 4. Anuwong A, Ketwong K, Jitpratoom P, Sasanakietkul T, Duh QY. Safety and outcomes of the transoral endoscopic thyroidectomy vestibular approach. JAMA Surg. 2018;153(1):21–7. 5. Fu J, Luo Y, Chen Q, Lin F, Hong X, Kuang P, et al. Transoral endoscopic thyroidectomy: review of 81 cases in a single institute. J Laparoendosc Adv Surg Tech A. 2018;28(3):286–91. 6. Russell JO, Razavi CR, Garstka ME, Chen LW, Vasiliou E, Kang SW, et al. Remote-access thyroidectomy: a multi-institutional North American experience with transaxillary, robotic facelift, and transoral endoscopic vestibular approaches. J Am Coll Surg. 2019;228(4):516–22.

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7. Anuwong A, Sasanakietkul T, Jitpratoom P, Ketwong K, Kim HY, Dionigi G, et al. Transoral endoscopic thyroidectomy vestibular approach (TOETVA): indications, techniques and results. Surg Endosc. 2018;32(1):456–65. 8. Razavi CR, Russell JO.  Indications and contraindications to transoral thyroidectomy. Ann Thyroid. 2017;2(5):ii. 9. Sasanakietkul T, Jitpratoom P, Anuwong A. Transoral endoscopic parathyroidectomy vestibular approach: a novel scarless parathyroid surgery. Surg Endosc. 2017;31(9):3755–63. 10. Razavi CR, Vasiliou E, Tufano RP, Russell JO. Learning curve for transoral endoscopic thyroid lobectomy. Otolaryngol Head Neck Surg. 2018;159(4):625–9.

Chapter 5

The Role of Ultrasound in Transoral Endocrine Surgery Eyas Alkhalili and Jason D. Prescott

Introduction The thyroid and parathyroid glands constitute the cervical endocrine organs, and associated disease states for which surgery is indicated are common. Identification of those patients who will require thyroid and/or parathyroid surgery, and subsequent preoperative planning, is a critical element of disease workup, and neck ultrasound is currently a required component of this assessment [1, 2]. Crude forms of thyroid ultrasonography were first described in the late 1960s, with thyroid tissue characteristics represented by two-dimensional changes in wave amplitude, visualized using an oscilloscope (A-mode/amplitude modulation). Improvements in ultrasound technology progressed rapidly thereafter, with development of basic two-dimensional gray-scale imaging (B-mode/brightness modulation), followed by modern high-resolution thyroid and parathyroid imaging (Fig.  5.1). In addition, development of new ultrasonography technology continues, with multiple recent studies examining the utility of reconstructed three-dimensional imaging, contrast imaging, and elastography for thyroid and/or parathyroid gland assessment [3]. Contemporary neck ultrasound is generally performed using standard linear transducers, including high-frequency (up to 18 mHz) and low-frequency (generally 8–10 mHz) probes, with and without color flow Doppler imaging. High-frequency ultrasound provides fine-resolution images of superficial neck structures, including most of the thyroid parenchyma, while low-frequency assessment allows visualization of deeper structures, including deep cervical lymph nodes and the tracheoesophageal groove. Color flow Doppler imaging provides objective information E. Alkhalili Department of Surgery, Texas Tech University Health Sciences Center, El Paso, TX, USA J. D. Prescott (*) Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA e-mail: [email protected] © Springer Nature Switzerland AG 2020 J. O. Russell et al. (eds.), Transoral Neck Surgery, https://doi.org/10.1007/978-3-030-30722-6_5

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50 Fig. 5.1 High-resolution B-mode gray-scale ultrasound image of a normal thyroid gland, transverse view. Panel a (top) shows typical ultrasound data. The relevant imaged anatomy is outlined and labeled in panel b (bottom) and includes the strap musculature anterior to the thyroid gland (sternohyoid and sternothyroid muscles), the right common carotid artery (CC), the right internal jugular vein (IJ), the trachea, the right thyroid lobe, and the thyroid isthmus

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regarding the extent of organ/nodal vascularity, which can inform risk of associated inflammation, as well as risk for primary and metastatic disease. Operative indications for thyroid and parathyroid disease have been well established [4–6]. Once an indication for thyroid and/or parathyroid surgery has been identified, associated neck ultrasound findings may be organized according to specific categories that impact operative approach selection. These categories include anatomic considerations, evidence for associated inflammation, and estimation of associated malignancy risk. In each case, the associated ultrasound findings inform the probability of achieving both successful (e.g., avoidance of conversion to a traditional open approach and complete resection of index nodular disease) and safe transoral surgery (e.g., risk of injury to the recurrent laryngeal nerves, parathyroid glands, and adjacent vascular structures). Although other imaging modalities, including computed tomography (CT) and magnetic resonance imaging (MRI) scanning, may augment ultrasound findings for some cervical endocrine disease (e.g., mediastinal pathology or poorly localized parathyroid disease), these studies are not adequate to supplant the role of preoperative ultrasound in surgical approach decision-making. Importantly, accurate, high-quality neck ultrasonography,

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e­specially for preoperative parathyroid disease assessment, requires technical expertise on the part of the performing provider [7]. Thus, preoperative neck ultrasound should be performed by an experienced ultrasonographer, preferably the operating surgeon, whenever thyroid and/or parathyroid surgery is planned.

 ltrasound Findings Informing Transoral Approach Selection U for Thyroidectomy and Parathyroidectomy Anatomic Considerations Anatomic exposure during transoral endocrine neck surgery is limited, relative to the open approach, by mechanical constraints imposed by the overlying intact skin and platysma muscle, as well as by the relative inability to retract potentially interfering anatomic structures laterally. Safe and successful transoral thyroid/parathyroid surgery thus requires manipulation of each thyroid lobe (in particular anterior retraction and medial rotation) in a necessarily restricted operative field. Preoperative identification of anatomic features that might interfere with such manipulation, and thus result in increased complication risks, is thus critically important when considering transoral surgery. In general, such potentially interfering features include large thyroid lobe/thyroid nodule size and unfavorable disease location (i.e., superior pole), both of which are readily assessed by cervical ultrasound.

Size High-resolution B-mode gray-scale ultrasound affords accurate three-dimensional size and volume estimation of each thyroid lobe, including associated nodules. The volume of each lobe and relevant nodules should be calculated preoperatively using sonographic craniocaudal, anterior-posterior, and medial-lateral measurements. Candidates for transoral thyroid/parathyroid surgery are those for which the relevant thyroid lobe is less than 10 cm in the largest dimension, for which the lobe volume is less than 45 mL, and for which the maximum nodule dimension is less than 5–6 cm (Fig. 5.2) [8–10]. Transoral exposure and dissection of the ipsilateral recurrent laryngeal nerve and parathyroid glands, as well as avoidance of excessive thyroidal tissue damage and associated intraoperative bleeding, are challenging when the ipsilateral thyroid lobe and/or nodules exceed these size specifications (Fig. 5.3). Successful transoral thyroid surgery also generally requires endoscopic transection of the thyroid isthmus, which facilitates medial and anterior thyroid lobe retraction, but may be technically challenging when the isthmus exceeds 1 cm in thickness, especially during the initial forays into remote access surgery. Finally, intraoperative identification of very small parathyroid adenomas localized during

52 Fig. 5.2 High-resolution B-mode gray-scale ultrasound, transverse view, of (a) a left thyroid lobe meeting size criteria for transoral approach thyroid lobectomy and (b) a right parathyroid adenoma amenable to transoral parathyroidectomy. The maximal dimension of the left lobe shown in panel A is 5.2 cm, and a 2-cm, mostly cystic, nodule is noted. The parathyroid adenoma (PA) shown in panel B measures 0.9 cm in maximal dimension, with the overlying thyroid lobe measuring 6.0 cm in its maximal dimension. CC, common carotid artery

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preoperative ultrasound (e.g., 10 cm in its maximum dimension and is too large for complete visualization via the ultrasound imaging window shown. Individual nodules (N) are outline by dashed yellow lines in panel b. CC, common carotid artery. Panel b: The nodule occupies virtually all of the visualized thyroid parenchyma and measures >6 cm in its largest dimension. The isthmus (I) is markedly thickened in both cases

angulation provided by placement of the working ports near the mouth commissures, transoral access to structures superior to the level of the hyoid cartilage may be extremely difficult, if not impossible, especially when the chin and thyroid cartilage are prominent. Lastly, the inability of endoscopic instrumentation to afford the sensitivity of digital palpation of tactile sensation (e.g., palpation) may translate to increased risk of injury to major anatomic and vascular structures. Preoperative high-resolution ultrasound can be extremely useful in identifying cervical endocrine disease potentially inaccessible/unresectable via a transoral approach, ­including some superior pole thyroid nodules, some superior parathyroid adenomas, and pyramidal lobes. Preoperative ultrasound can also identify thyroid nodules or parathyroid adenomas that localize near the course/insertion site of the ipsilateral recurrent laryngeal nerve (e.g., just posterior to the cricothyroid joint). Such disease may obscure transoral endoscopic visualization of the recurrent laryngeal nerve at

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this critical location, potentially increasing risk of nerve injury. Known thyroid cancers abutting the expected course of the recurrent laryngeal nerve may be found intraoperatively to directly invade the nerve, and an open approach to such cancers should thus be favored, especially early in the learning curve. Finally, substernal/ mediastinal thyroid extension may be discovered during preoperative neck ultrasound. Transoral endoscopic resection of such disease may be challenging, as associated cephalad thyroid retraction may not be possible in the constrained working space afforded by this approach [11]. Preoperative parathyroid disease localization plays a critical role in operative planning for primary, secondary, and tertiary hyperparathyroidism (see the chapter on parathyroid surgery). Optimal preoperative parathyroid localization generally involves multiple imaging modalities, including ultrasound, sestamibi scanning, and/or four-dimensional (4D) CT imaging. Transoral approach parathyroidectomy is contraindicated when such imaging is negative (thus potentially necessitating extensive operative neck exploration, which is best accomplished via an open surgery) or reveals parathyroid disease inaccessible via a transoral approach, including mediastinal, high carotid sheath, posterior esophageal, and posterior laryngeal localization. The presence of multigland/four-gland parathyroid disease does not, in itself, contraindicate a transoral approach, so long as all involved disease is accessible using this technique.

Inflammation Inflammation and its sequelae, regardless of etiology, can produce tissue changes that increase the associated degree of operative difficulty and therefore both the risk of related surgical complications and of conversion from a laparoscopic/endoscopic procedure to an open approach [12–15]. The most common active inflammatory conditions impacting operative difficulty in cervical endocrine surgery are lymphocytic (Hashimoto’s) thyroiditis and Graves’ disease. The important associated inflammatory tissue changes can include (1) increased tissue vascularity (Fig. 5.4), leading to increased intraoperative bleeding risk and, consequently, impaired visualization of the operative field, as well as potentially higher postoperative hematoma formation risk, and (2) increased tissue friability, making avoidance of tissue damage (and associated bleeding) during gland manipulation/retraction more challenging. Chronic sequelae of tissue inflammation impacting operative difficulty are generally the result of scar tissue formation, which can obliterate normal tissue planes and distort involved anatomy. Such chronic changes, which are generally not appreciated during preoperative imaging, are most relevant for reoperative thyroid/ parathyroid surgery and in cases of previous high-dose radiation exposure (e.g., external beam neck irradiation or radioactive iodine therapy). Because the tissue changes associated with active/previous inflammation increase operative difficulty, associated complication rates are generally higher, and, overall, such cases may be more safely managed using an open surgical approach [16, 17]. For these reasons,

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Fig. 5.4  Transverse view high-resolution B-mode ultrasound images of the thyroid gland in the context of severe lymphocytic thyroiditis (panels a and b, both thyroid lobes shown, gray-scale and Doppler overlay images, respectively) and Graves’ disease (panels c and d, right thyroid lobe shown, gray-scale and Doppler overlay images, respectively). Representative transverse view high-resolution images for normal thyroid tissue are also shown for comparison, without and with color flow Doppler overlay (panels E and F, respectively, both thyroid lobes shown). The presence of red and blue color in the Doppler overlay images indicates degree of vascularity and vascular distribution. The thyroid isthmus, trachea, and common carotid artery (CC) are labeled for panels a, c, and e

transoral endocrine neck surgery is generally not recommended when these conditions are present, especially during the learning stages for this approach. It is important to note that although an inflammatory process may originate in a single structure or focused anatomic area (e.g., lymphocytic thyroiditis or Graves’ disease originating in the thyroid), the related inflammation exerts a field effect in the general anatomic vicinity, thus potentially impacting operative difficulty for any procedure

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planned in the area. Parathyroidectomy, for example, performed in the context of significant lymphocytic thyroiditis, can be expected to be more difficult than when the adjacent thyroid is not inflamed. Although the presence of inflammation is determined on the basis of preoperative history, physical examination, and/or biochemical testing, cervical ultrasound can play an important adjunctive role in the assessment of active associated inflammation, and thus in operative approach selection, when endocrine neck surgery is planned. Ultrasound findings indicating active inflammation related to lymphocytic thyroiditis include gland enlargement, increased thyroid parenchyma heterogeneity, and expanded gland vascularity. Figure 5.4 shows representative ultrasound images for severe lymphocytic thyroiditis, with and without color flow Doppler overlay (panels A and B). These images demonstrate marked enlargement of the thyroid gland, with significant increase in tissue heterogeneity, and expansion of the associated vascular supply, relative to the normal thyroid example shown (panels E and F). Similarly, panels C and D show gland enlargement, vascular supply expansion, and increased tissue heterogeneity associated with Graves’ disease. Such gland features, when identified during preoperative neck ultrasonography, may be predictors of increased operative difficulty, and the potential for increased surgical risk should be discussed with the patient preoperatively. Finally, thyroid nodule aspiration biopsy may also produce local inflammatory changes that can impact operative difficulty. Such changes are uncommon, however, and are generally focal and mild. Thus, previous history of aspiration biopsy is not, in itself, a contraindication to a transoral approach for endocrine neck surgery.

Malignancy The incidence of thyroid cancer is increasing and malignancy, or concern for malignancy, is a common indication for thyroid surgery [1]. Any surgical approach employed for cancer treatment must not only be safe but must also afford an oncologically optimal outcome. Oncologic outcomes associated with transoral thyroid surgery are under active investigation, and the efficacy of this approach for patients diagnosed with thyroid cancer is thus unclear. In light of this uncertainty, current formal indications for transoral endoscopic thyroid surgery, when thyroid malignancy is present or is suspected, are appropriately conservative, being limited to (1) welldifferentiated thyroid microcarcinomas (1 and ≤4 cm: is the need for completion thyroidectomy common among patients submitted to lobectomy? Clin Endocrinol (Oxf). 2016;85(1):150–1. 62. Kluijfhout WP, Pasternak JD, Lim J, et  al. Frequency of high-risk characteristics requiring total thyroidectomy for 1-4 cm well-differentiated thyroid cancer. Thyroid. 2016;26:820–4. 63. Lang BH, Shek TW, Wan KY. The significance of unrecognized histological high-risk features on response to therapy in papillary thyroid carcinoma measuring 1-4 cm: implications for completion thyroidectomy following lobectomy. Clin Endocrinol. 2017;86:236–42. 64. Vaisman F, Momesso D, Bulzico DA, et al. Thyroid lobectomy is associated with excellent clinical outcomes in properly selected differentiated thyroid cancer patients with primary tumors greater than 1 cm. J Thyroid Res. 2013;2013:398194.

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65. Yeh MW. Moving towards perfection: avoiding unnecessary surgery, eliminating complications, and reducing costs. American Thyroid Association Meeting in Victoria BC. 2017. 66. Esnaola NF, Cantor SB, Sherman SI, et al. Optimal treatment strategy in patients with papillary thyroid cancer: a decision analysis. Surgery. 2001;130:921–30. 67. Shrime MG, Goldstein DP, Seaberg RM, et al. Cost-effective management of low-risk papillary thyroid carcinoma. Arch Otolaryngol Head Neck Surg. 2007;133:1245–53. 68. Lang BH, Wong CKH. Lobectomy is a more cost-effective option than total thyroidectomy for 1 to 4 cm papillary thyroid carcinoma that do not possess clinically recognizable high-risk features. Ann Surg Oncol. 2016;23:3641–52. 69. Kluijfhout WP, Rotstein LE, Pasternak JD. Well-differentiated thyroid cancer: thyroidectomy or lobectomy? CMAJ. 2016;188:E517–20. 70. Razavi CR, Tufano RP, Russell JO. Completion thyroidectomy via the transoral endoscopic vestibular approach. Gland Surg. 2018;7:S77–9. 71. Anuwong A, Ketwong K, Jitpratoom P, et al. Safety and outcomes of the Transoral endoscopic thyroidectomy vestibular approach. JAMA Surg. 2017;153(1):21–7.

Chapter 7

Surgical Equipment, Supplies, and Setup for Transoral Thyroid and Parathyroid Surgery via the Vestibular Approach Young Jun Chai, Özer Makay, Che-Wei Wu, Hoon Yub Kim, and Gianlorenzo Dionigi

Introduction A new surgical technique has to maintain or advance relative to the conventional standard procedure and be at least comparable when it comes to results achieved, complications, safety, technical feasibility, and cost-to-benefit ratio. Considerable developments have occurred in the application of endoscopic techniques in thyroid surgery. Gagner and Miccoli first reported successful endoscopic neck surgery in 1996 and 1997 [1, 2]. About 20 different hybrid endoscopic thyroid surgical techElectronic Supplementary Material The online version of this chapter (https://doi. org/10.1007/978-3-030-30722-6_7) contains supplementary material, which is available to ­authorized users.

Y. J. Chai Department of Surgery, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, South Korea Ö. Makay Division of Endocrine Surgery, Ege University Hospital, Bornova, Izmir, Turkey C.-W. Wu Department of Otorhinolaryngology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University Hospital, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan H. Y. Kim Department of Surgery, Korea University College of Medicine, Seoul, South Korea Korea University Hospital, Seoul, South Korea G. Dionigi (*) Division of Endocrine and Minimally Invasive Surgery, University of Messina, Varese, Italy e-mail: [email protected] © Springer Nature Switzerland AG 2020 J. O. Russell et al. (eds.), Transoral Neck Surgery, https://doi.org/10.1007/978-3-030-30722-6_7

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niques have been developed since [3]. Minimizing psychological stress, cosmetic concerns, and improving the postoperative quality of life of patients are the main motivations for developing novel endoscopic thyroid surgical techniques. According to the insertion site of surgical instruments, endoscopic surgery can be classified as cervical, anterior chest wall, breast, axillary, axillary breast approaches, and transoral via vestibular incision [3]. While there has always been a desire to minimize the cosmetic impact of thyroid surgery through smaller, less conspicuous incisions resulting in a rapid evolution of remote-access approaches to the thyroid, transoral thyroidectomy is the only approach that avoids all cutaneous scarring. Transoral thyroidectomy is made possible with the use of endoscopic and robotic technology through a novel, scarless approach in the lower vestibulum of the oral cavity (lower lip) [4, 5]. The evolution of thyroid surgery from a large incision in the neck to remote-access, scarless approaches has in large part been made possible by advancements in laparoscopic and robotic technology, devices, and accessories [3]. While these tools have been used for remote-access thyroid surgery from various approaches from the chest, axilla, and neck areas, there are unique challenges with the transoral approach that require familiarity with the requisite instrumentation [5]. In this chapter, we highlight pre- and postoperative aspects of transoral endoscopic thyroidectomy vestibular approach (TOETVA) in patient management, operative room setup, and instrumentation. As with any new procedure, proper instrumentation and familiarity with all elements of the operation are of paramount importance.

Preoperative Peculiarities Inclusion and Exclusion Criteria The results of previous reports and studies on TOETVA support the importance of careful selection of patients for outcome measures and the impact that precise patient candidacy and safety have on outcome [6–8]. The patient selection criteria must be strictly observed to maintain TOETVA safety. The inclusion and exclusion criteria used for TOETVA are summarized in Tables 7.1 and 7.2. Relative contraindications are morbid obesity and ASA 3 or 4 [6–8]. Furthermore, it is important to specify that male candidates are more challenging for the TOETVA Table 7.1  Indications for TOETVA Predicted gland width on diagnostic imaging ≤10 cm Thyroid volume outline of 45 mL Main nodule diameter of >50 mm Documentation of lymph node Distant metastases Tracheal/esophageal infiltration Preoperative laryngeal nerve palsy Hyperthyroidism Mediastinal goiter Oral abscess Patients with poorly or undifferentiated cancer Dorsal extrathyroidal tumor Lateral neck metastasis

procedure because: (a) chin to neck region step is more difficult to dissect because of more robust tissues (b) laryngeal prominence/thyroid cartilage is larger in adult men and interferes with vision and instrumentation.

Preoperative Imaging All patients are evaluated preoperatively using ultrasonography and fine-needle aspiration [9]. This topic is covered further in the chapter on ultrasonography found previously in this text. Imaging is essential to identify the proper patient for TOETVA.  Imaging should demonstrate an uncomplicated surgical disease. Preoperative US is mandatory, with evaluation of the following three proper “s” site, size, and shape (oval). Proper site (for ideal candidates) indicates: (a) Not too low (near the suprasternal notch). (b) Not too high (upper pole dissection). (c) It should be not too deep (posterior), not adhere to carotid sheath, and not hide underneath SCM muscle. Proper nodule size (for ideal candidates) indicates: (a) Less than 4 cm nodules that are not likely to be cancer. (b) Easy to see endoscopically. (c) It is not difficult to dissect. (d) It is not too hard to handle when you look for the RLN. (e) It is not too complicated to put the nodule into the endo-bag and remove from the vestibule.

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Pre- and Postoperative Laryngoscopy All patients undergo preoperative direct laryngoscopy to assess vocal cord motility [10]. TOETVA is still in the development phase, which is yet another reason why laryngoscopy should be performed for auditing. A preoperative finding of RLN palsy should be a contraindication for TOETVA.

Surgeon Candidacy For the general surgeons, it is important to have enough experiences in open thyroid surgery, training in endoscopic thyroidectomy, and familiarity in laparoscopy (i.e., retroperitoneal) [11]. For the head and neck surgeons, surgeons should have wide experience in open and endoscopic thyroid surgery and should be familiar with endoscopy (i.e., sinus surgery) [11]. All surgeons should know about the anatomy of the oral cavity (lip and chin) and neck and how to best protect the RLN, mental nerve, and parathyroid glands. The left lobectomy in a male patient with a significant laryngeal prominence is initially more challenging for the right-handed surgeon because of the instruments’ collision, at least for the original cases. Female patients with a right thyroid nodule are the most proper candidate for the right-handed surgeon to begin TOETVA, and the converse is true for the left-handed surgeon.

First Assistant The first assistant should have experience in using a 30 or 45° camera to visualize the operative field effectively. The first assistant is important and ideally: (a) Helps to hold the camera correctly (b) Key person to help endoscopic surgery become a success (c) Well informed/knowledgeable on TOETVA steps (d) Clearly understands all steps of operation (e) To be able to “read surgeon’s mind” and anticipate next steps (f) Fluent and active

Second Assistant A second assistant, or third person involved in the surgery, might be necessary for external skin retraction stitches (Fig. 7.1). On the contrary, the external retraction stitches can be tied to a pulley (Fig. 7.2).

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Fig. 7.1  A second assistance might be necessary for external skin retraction stitches

Fig. 7.2 External retraction stitches tied to robot pulley

Nurse Ideally, the circulating nurse and surgical technician will be stable across multiple cases in order to improve the knowledge and skill of TOETVA. These members of the team check the TOETVA equipment before starting surgery. The surgical technician may offer valuable insight on the indications of endoscopic surgery and its practical application (laparoscopic, thoracoscopic, sinus surgery, etc.). The surgical scrub nurse should have knowledge of maintenance and sterilization of endoscopic instruments and raise awareness of specificities of endoscopic surgery, knowledge of minimizing endoscopic complications, and knowledge of

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endoscopic preoperative preparation and postoperative care. The team keeps endoscopic instruments as clean as possible. And also remove excess instruments from the surgical field, and inform surgeons the instrument and gauze count at the end of surgery.

Surgical Anatomy Transoral thyroidectomy is performed with a cranial to caudal view, and the dissection proceeds from a cranial to caudal direction. However, as most surgeons are familiar with caudal to cranial dissection, the authors suggest to practice dissection from a cranial to caudal direction during open surgery to learn identifying the RLN at its entry point before beginning the first case of TOETVA [6–8].

Patient Preparation Dental Care Before starting your first transoral case, it may be appropriate to interact and discuss with your dental specialist. Oral microbiology includes anaerobic bacteria: Actinomyces, Arachnia, Bacteroides, Bifidobacterium, Eubacterium, Fusobacterium, Lactobacillus, Leptotrichia, Peptococcus, Peptostreptococcus, Propionibacterium, Selenomonas, Treponema, and Veillonella. Genera of fungi that are frequently found in the mouth are as follows: Candida, Cladosporium, Aspergillus, Fusarium, Glomus, Alternaria, Penicillium, and Cryptococcus. A highly efficient innate host defense system constantly monitors the bacterial colonization and prevents bacterial invasion of local tissues [12, 13]. However, the three vestibular incisions determine a new communication between the oral cavity and neck, and poor oral heath may contribute to the ability of the oral microbiota to invade the body. Good oral and dental hygiene can prevent possible postoperative infective complications [14, 15]. The long term impact on the gingiva is also not clearly understood.

Prophylactic Antibiotic Amoxicillin/clavulanic acid is commonly used for the preoperative prophylactic antibiotic. Some authors suggest extending the antibiotic for 5 days postoperatively orally [6–8, 12–15].

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b

Fig. 7.3 (a, b) The operative room setting scheme (a) and intraoperative picture (b). The IONM monitor is set at patient foot. Other options may include the integration of monitoring screen into the HD monitor, a console design with mobile arm, and use of mini-screen or iPad or Google glass

Operation Room Setup Figure 7.3a, b demonstrates the logistics of the operating room. The surgeon works on the patient’s head, with the first assistant to his left possibly sitting on a chair so as not to interfere with the fine movements of the first surgeon (Fig. 7.4). A second assistant is on the left of the first assistant. The scrub nurse is near the first surgeon on his right, as per the general rules of the operating room. The HD monitor and instrumentation are at the feet of the patient. The monitor should be clearly visible and accessible to all on the surgical team. Anesthesia devices should not interfere with the surgical team and the view of the monitor [16].

Anesthesia Perspectives The patient can be intubated orally or nasally, depending on the patient condition and surgeon and anesthesiologist preference. Nasal intubation is not a prerequisite for surgery. If oral intubation is chosen, it is recommended to firmly affix the tube to the upper lip to prevent inadvertent dislodgement during the procedure (Fig. 7.5). The tube must be fixed to the upper lip, not to the lower lip as is part and site of the surgical procedure [17].

Positioning The patient is placed supine on the operative table. The neck is slightly extended in the midline: a shoulder roll or balloon allows for modest neck extension [18], but this is not necessary in all cases. Head donut/roll is suggested to stabilize head dur-

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Fig. 7.4  The surgeon works on the patient’s head, with the first assistant to his left possibly sitting on a chair so as not to interfere with his arms and the camera to the fine movements of the first surgeon

ing manipulation. Moreover, two side lateral cushions or a plaster can be used to fix the head to the operating table to limit the head movement during the operation (Fig. 7.6). The patient and table can be placed in a Trendelenburg position up to 30° if this is desired: in this way the direction of the surgery, dissection, and endoscopic vision from the lower vestibule and chin is directed preferably toward the neck [18].

Disinfection The disinfection of surgical field comprises superiorly up to the upper lip, the lower lip, and the chin. The whole neck must be disinfected and a neck incision marked in case there is the need for conversion to an open approach [19]. Povidone-iodine solution or an alternative is recommended for disinfection on the neck and the chest. When disinfecting the surgical field, especially the upper lip, make sure that the disinfectant does not reach the patient’s eyes or the nasal cavity. It is useful to cover them previously with a gauze or patch for protection.

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Fig. 7.5  EMG tube for nerve monitoring

Fig. 7.6  Head donut/roll is suggested to stabilize head during manipulation. Moreover, two side lateral cushions are placed at the head and a plaster fixed to the head and to the operating bed, to avoid that the head is tossed during the operation

Intraoral Solutions for Irrigation Either chlorhexidine or povidone-iodine may be used for intraoral irrigation if you find this to be of value, but it is not used by all surgeons. If desired, an Irrigation spoid can be used for irrigating efficiently (Fig. 7.7). At the end of oral hygiene, it is advisable to remove the excess of the disinfectant, in order not to keep it too long in contact with the mucosa of the oral cavity [20]. Alcohol disinfectants should be

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Fig. 7.7  Irrigation spoid

Fig. 7.8 Transparent draping

avoided. At the end of disinfection, thorough irrigation with normal saline solution can be performed. It may also be helpful to keep gauze in the oral cavity during surgery to collect blood clots, which will be removed at the end of the operation. The gauze is also useful for the “tube packing,” which may allow the endotracheal tube to be kept in place, anteriorly, and well in contact with the vocal cords [20].

Draping Draping can be done in the usual manner for open thyroidectomy (Fig.  7.8). Transparent draping for the patient’s side of the head has advantages in that a surgeon can easily notice the status of the endotracheal tube and quickly respond to possible tube dislocation [21, 22]. Particular care must be taken in protecting the patient’s eyes (rigid eye shields) and nose with a layer of gauze, to avoid any ­decubitus of the endoscopic instruments on them during TOETVA (Fig. 7.9).

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Fig. 7.9  Particular care must be taken in protecting the patient’s eyes (rigid eye shields) and nose with a layer of gauze, to avoid any decubitus of the endoscopic instruments on them during TOETVA

Fig. 7.10  A gauze should be placed on the endotracheal tube, so that the adhesive of the draping, when removed, does not move accidentally the endotracheal tube

A gauze can be placed on the endotracheal tube, so that the adhesive of the draping, when removed, does not accidentally move the endotracheal tube (Fig. 7.10). The definitive surgical field is represented in Fig. 7.11. We suggest drawing on the skin the laterality of the dominant nodule to be removed and the anatomical references, such as the midline, the margins of the sternocleidomastoid muscle, and the sternal notch (Fig. 7.11). A throat pack can be placed to collect shed blood, bodily or external fluids, and other materials that may collect in the oropharynx. Intraoperative US may also be helpful in marking the anatomical landmarks and location of the index thyroid nodule or suspected putative parathyroid gland.

Surgical Equipment General Excellent surgical equipment is necessary for the success of TOETVA [23, 24]. The surgical team should always consider (a) high-quality vision, (b) best exposure, (c) seal and cut (hemostasis) devices, (d) dissection devices, (e) complementary devices

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Fig. 7.11  Surgical field

(i.e., nerve monitoring, fluorescence, etc.), (f) removal of specimen accessories, and (g) alternatives if standard instrumentation or equipment fails or is not available. A conventional thyroidectomy tray is recommended in the room should conversion to an open procedure be necessary. Furthermore, only a few standard instruments are required to begin the procedure (vestibular incisions and initial subplatysmal dissection) including soft tissue forceps, a scalpel, and tissue dissectors. A standard soft tissue tray contains the necessary equipment. Additional instrumentation required to make the subplatysmal working space in the neck are listed below. Most laparoscopic trays contain the necessary instrumentation. It is important to consider the length of the neck to better select the surgical endoscopic instruments [23, 24]. Considering 50 consecutive patients subjected to TOETVA (personal communication), the average distance between the lower lip and the sternal notch is about 19  cm (Fig.  7.12): therefore it is advisable to use endoscopic instruments and accessories of greater length. Furthermore, considering the limited field and the surgical procedure itself, the ideal TOETVA instrumentation should include the following proprieties: sterile, covered, thin (800 mcV, with a 2 mA stimulation Fig. 7.43  Stimulation of the RLN after complete thyroidectomy and hemostasis (R2). Stimulation is achieved with the long stimulation probe. Amplitude obtained is >750 mcV, with a 1 mA stimulation

Fig. 7.44  Identification of the external branch of superior laryngeal nerve (black arrow) using ball tip stimulation probe, which should be saved during the ligation of the superior thyroidal vessels (white arrow)

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Table 7.4  Comparison of different intermittent stimulation methods for IONM in TOETVA Intermitted stimulating probe Percutaneous

Advantages V1, R1, S1, S2, R2, V2 Same instrument open procedure Cost saving Incrementing probe (preferable, remote console control, capture events, etc.) Flexibility Ball tip Periodic continuous stimulation (V, R) No need of ports use, no need to change instruments

Disadvantages Additional step/procedure Further skin neck incision Two skin incisions (bilateral procedure) Possible loss of CO2 insufflation Higher stimulation intensity needed (2–3 mA) Tip wearing Hindrance: instruments interference when held in place Disposable Dedicated long probe Change instrument Additional cost/OR availability Tip not flexible Not available incrementing probe/remote control Some loss of CO2 insufflation from port Need of port Disposable Hindrance, some instrument interference No ball tip Disposable Space use in trocar and possible displacement during port use Not commercially available Installation Shift between coagulation and stimulation Special adapter and cable

Long probe

V1, R1, S1, S2, R2, V2 No additional neck skin incisions Lower-intensity stimulation (percutaneous) Versatility (bilateral use) Ball tip

Flexible wire probe

V1, R1, S1, S2, R2, V2 No additional neck skin incisions, inserted into port Lower-intensity stimulation Versatility (bilateral use) Endoscopic and robotic use

Endoscopic instrument

V1, R1, S1, S2, R2, V2 No additional neck skin incisions Endoscopic and robotic use Perform dissecting and stimulating same time Minimize instrument interference Non-CO2 loss insufflation Versatility (bilateral use) Intensity stimulation = open surgery Higher EMG amplitudes Reusable Ergonomics Not commercially available V1, R1, S1, S2, R2, V2 Dissecting, hemostatic, and stimulating Cooling time Disposable at the same time No additional neck skin incisions Endoscopic and robotic use Versatility (bilateral use) Ergonomics

Energy-based device (EBD) instrument

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Chen et al. reported their preliminary experience in the placement of wire delta stimulating electrode for continuous VN stimulating during TOETVA [63]. The potential drawbacks and pitfalls of use of continuous IONM in TOETVA include as follows: increased setup time, extra cost, cannot completely replace intermittent IONM, increase in the risk of injury to the carotid sheath organs (internal jugular vein, carotid artery, and VN), and increased potential cardiopulmonary effect by VN stimulation [67]. Therefore, the safety and cost-effectiveness of using continuous stimulating electrodes for IONM need to be further investigated in future studies. Recording Electrodes Currently, endotracheal tube-based electrodes are now most widely used commercially available monitoring systems [64]. The benefits include its availability, safety, non-invasive nature, ease setup, ease use, and derive larger areas of evoked muscle potentials. The recording electrode sites have also been reported to include laryngeal palpation, glottic observation, glottic pressure monitoring, endoscopically placed intramuscular vocal cord electrodes, intramuscular electrodes placed through the cricothyroid membrane, postcricoid surface electrodes, and sub-perichondrium thyroid cartilage electrodes [64]. However, few of these methods were regularly used, and the use of none has been reported in TOETVA. During TOETVA, the EMG tube can be intubated orally or nasally. Orotracheal intubation is used widely with advantage of quicker and easier placement. However, orotracheal intubation has some disadvantages including that it is more difficult to secure, there is a risk of accidental extubation, and there is possible hindrance of surgical maneuvers. In contrast, nasotracheal intubation can offer more space in TOETVA and is thus preferred by some surgeons. However, the disadvantages of nasotracheal intubation include more difficult placement, inadequate available size and length to maximize tube/electrodes contact with vocal cord, and potential risk of nasal complications. The contraindications of nasotracheal intubation are listed in Table 7.5. Malpositioning of the endotracheal surface electrodes can result in dysfunction of IONM and increase the risk of RLN injury. Although there is no report about the prevalence of oro- or nasotracheal EMG tube displacement during TOETVA, it is expected the prevalence is higher than conventional open thyroidectomy because there is more surgical manipulation near the mouth or nose area. Therefore, for Table 7.5  Contraindications of nasotracheal EMG tube intubation for TOETVA Absolute Suspected epiglottitis Midface instability Coagulopathy Suspected basilar skull fracture

Relative Large nasal polyps Suspected nasal foreign bodies Recent nasal surgery Upper neck hematoma or infection History of frequent episodes of epistaxis

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Table 7.6  Pros and cons of EMG tube oral vs. nasotracheal intubation Type intubation Orotracheal

Nasotracheal

Advantages Quicker and easier Less displacement with Patient head movement Proper ID: tube/electrodes contact with VC Less contamination of trachea No hindrance More easily secured Less extubation rate

Disadvantages More difficult to secure Accidental extubation Hindrance Troubleshooting algorithms: difficult management of EMG tube dislocation Tube collapse TriVantage (FDA warning 2013) More difficult to insert More displacement with head movement Inadequate length of EMG tube available Inadequate ID: tube/electrodes contact with VC FLEXtube not usable due to wires Troubleshooting algorithms: difficult management of EMG tube dislocation Epistaxis Trauma to the turbinates Risk of bacteremia during insertion Sinus and Eustachian tube blockage

setup of a functional IONM during TOETVA, proper electrode position verification with repeat laryngoscopy should be considered once the patient is positioned for surgery. In addition, depth of tube insertion and degree of rotation relative to VC should be monitored and noted directly by both the surgeon and anesthesiologist during surgery (Table 7.6). Nerve Monitor Systems The recommended operation room setup for IONM during TOETVA is shown in Figure 7.3a, b. Basically, the nerve monitor systems should be placed near the HD monitor to facilitate reading by the surgeon. The possible alternative ways to display the EMG responses include integration with HD monitor, a console design with mobile arm, and use of mini-screen, iPad, and Google glass.

EBSLN Monitoring IONM has the potential to be utilized for identification of the external branch of the superior laryngeal nerve (EBSLN) and functional assessment of its integrity; therefore, IONM might contribute to voice preservation following thyroidectomy [68]. Recently, Dionigi et al. added two new steps in IONM for the diagnosis of possible intraoperative EBSLN injury, which includes (1) S1-step, the early identification and first EBSLN stimulation, and (2) S2-step, the final EBSLN stimulation at the

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Fig. 7.45  Use of fluorescence imaging technique in TOETVA

end of the surgical procedure, after complete hemostasis and STA ligation [69]. Therefore, the six-step procedure V1-R1-S1-S2-R2-V2 can also be used as a standard to follow during the IONM in TOETVA [68, 69] (Fig. 7.45).

Fluorescence Imaging in Transoral Thyroidectomy? Identification of the parathyroid glands during the operation is the key to avoid postoperative hypocalcemia. Recently, fluorescence imaging techniques have been used to help the identification of the parathyroid glands. Indocyanine green (ICG) fluorescence is the most commonly used technique. ICG is a water-soluble amphiphilic tricarbocyanine dye with near-infrared fluorescent properties, and excitation of ICG in plasma with light generates fluorescent light with wavelengths of 830–845 nm [70]. ICG was approved by FNA for clinical use in 1959 and can be safely used intravenously up to 30  mg. Once administered intravenously, ICG is absorbed at the tissue and fluoresces under near-infrared light. Using this property, surgeons can use ICG for the identification of parathyroid glands. To use this technique, the surgeon requires specific devices to detect the fluorescence from the tissues such as Pinpoint® system (Novadaq, Toronto, Canada). For the procedures, 5–10 mg of ICG is injected after dissecting the strap muscles from the thyroid gland. Then in 2–3  minutes, parathyroid glands fluoresce before thyroid gland, and the surgeon can identify the location of the parathyroid glands (Fig. 7.45).

Future Directions and Conclusions Thyroid surgeons have started performing increasingly complex procedures involving tumor resection, prophylactic node dissection, endoscopic or robotic surgery, and transoral procedures as the TOETVA.  Cosmetic thyroid surgery is rapidly

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becoming a common issue in a busy endocrine surgery practice. Improving cosmetic outcomes have been a direct and logical derivative of technical advances, minimally invasive and endoscopic approaches, and societal and cultural needs. Avoidance of a cervical incision is important to many individuals. A standardized approach to TOETVA that we highlighted may accomplish the goal of scarless surgery most safely.

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Chapter 8

Transoral Endoscopic Vestibular Approach Technique: Steps, Tips, and Pearls Angkoon Anuwong, Khwannara Ketwong, Tanyanan Jamikorn, Isariya Jongekkasit, Thanyawat Sasanakietkul, and Pornpeera Jitpratoom

Introduction Theodor Kocher was instrumental in reducing the mortality rate associated with thyroidectomy from 40% to 0.2% in 1895 [1, 2] by standardizing the steps of the procedure. The desire to avoid a scar in the neck and emphasis on cosmesis led to the development of remote-access approaches to the thyroid gland. In 1999, Miccoli et al. performed the first video-assisted minimally invasive thyroidectomy [3–6]. Other approaches such as transaxillary, chest, axillo-breast, subclavian, and retroauricular have been performed. However, these approaches still left a visible surgical scar. In 2008, the first thyroidectomy with transoral approach via the floor of the mouth was performed in pigs and human cadavers and tried on patients in Germany [7–9]. Unfortunately, the rates of mental nerve and hypoglossal nerve injury and conversion rates were high, and it was quickly dismissed [8, 9]. Transoral approach via vestibular route was introduced to overcome the complications from floor-of-­ mouth dissection [10–12]. All three ports were inserted into the oral vestibule with a central camera port and two side ports for instrument and ultrasonic scalpel device. To our knowledge, ours was the first large series that reported12 successful outcomes in 60 patients undergoing transoral thyroidectomy using the vestibular approach. This chapter aims to take the reader through the steps of the procedure.

A. Anuwong (*) · T. Jamikorn · I. Jongekkasit · T. Sasanakietkul · P. Jitpratoom Minimally Invasive and Endocrine Surgery Division, Department of Surgery, Police General Hospital, Bangkok, Thailand K. Ketwong Department of Surgery, Chiang Rai Prachanukroh Hospital, Chiang Rai, Thailand © Springer Nature Switzerland AG 2020 J. O. Russell et al. (eds.), Transoral Neck Surgery, https://doi.org/10.1007/978-3-030-30722-6_8

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Indications • Benign lesion such as single nodule, multinodular goiter, Graves’ disease, or toxic adenoma • Thyroid nodule less than 6 cm in diameter • Total size of thyroid gland less than 10 cm in diameter per one lobe • Cancer nodule