Instrumentation and technological future directions for transoral thyroidectomy

Introduction

While there has always been a desire to minimize the cosmetic impact of thyroid surgery through smaller, less conspicuous incisions resulting in the development of remote-access approaches to the thyroid, transoral thyroidectomy is the only approach that avoids all cutaneous scarring. The evolution of thyroid surgery from a large incision in the neck to remote-access, scarless approaches have in large part been made possible by advancements in laparoscopic and robotic technology. 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.

The technical details of both transoral endoscopic trans-vestibular approach (TOETVA) and transoral robotic thyroidectomy (TORT) are described elsewhere in this volume. This chapter will focus on the instrumentation necessary for each procedure. The instrumentation for both TORT and TOETVA is the same with the addition of robotic instrumentation for TORT, noted below. The surgical prep tables with instrumentation is demonstrated (Figure 1). Additionally, a conventional thyroidectomy tray is recommended in the room should conversion to an open procedure be necessary.

Figure 1 The surgical table with both laparoscopic and standard instrumentation before surgery start.

Positioning and preparation

The patient is placed supine on the operative table and intubated either orally or nasally depending on surgeon preference (Figure 2). If oral intubation is chosen, it is recommended to firmly affix the tube (e.g., consider suture fixation to the dentition) to prevent inadvertent dislodgement during the procedure. The neck is slightly extended in the midline. Anesthesia should be positioned near the feet of the patient to allow access to the top and both sides of the head by the surgeon and assistants. Key recommended instrumentation is noted in Table 1.

Figure 2 Intraoperative positioning of the patient prior to surgery start.

Procedure start and flap elevation

Only a few standard instruments are required to begin the procedure including soft tissue forceps, a scalpel, tissue dissectors and cautery. A standard soft tissue tray contains the necessary equipment. Additional instrumentation required to make the subplatysmal working space in the neck are listed in Table 2. Most laparoscopic trays contain all the necessary instrumentation but the required tools are listed below.

Figure 3 Custom fabricated soft tissue dissector used to make subplatysmal working space.

Figure 4 5 mm laparoscopic cannula with side port to allow for venting of vapor plume.

Figure 5 Vision cart is placed at the foot of the patient to allow surgeon, assists, scrub techs, nurses and anesthesia to all view the procedure together.

Central neck work

Thyroid lobectomy, total thyroidectomy, central neck dissections, and parathyroidectomy may all be completed via the transoral approach, either laparoscopically or robotically. If robotic instrumentation is used (Table 3), it is usually docked during or immediately after the creation of the subplatysmal working space. For TOETVA, instrumentation in Table 2 is used.

Specimen extraction and closure

Once the specimen has been completely freed it is necessary to remove it atraumatically from the neck through the central lip trocar site. The specimen must be placed in a specimen extraction bag (Figure 6) so that it is not torn and does not contaminate the endoscopic tunnel with seeded tissue. Instrumentation for this retrieval and closure are in Table 4.

Figure 6 10 mm endo catch bag for specimen retrieval.

Future directions

TONS is a relatively new procedure that will likely see considerable evolution in instrumentation and technique over the years. The technical feasibility of transoral neck surgery will likely improve as instrumentation is developed specifically for this task. Both the endoscopic and robotic techniques have shortcomings that will hopefully be overcome. TOETVA is limited in that it uses standard laparoscopic instrumentation that is not wristed, requires an experienced bedside assistant surgeon to hold the scope, and has a 2 dimensional view. Each of these limitations will likely be addressed in the near future. Wristed laparoscopic instrumentation is under development (e.g., FlexDex Surgical, Brighton, MI). Wristed instrumentation allows for increased range of motion of the distal arm of the instrument and avoids line-of-site issues that occur while looking down the shaft of rigid endoscopic instrumentation. It is felt to greatly assist with fine dissection and has been touted as critical by those surgeons who prefer the robotic approach. Custom made scope holders will free up one of the hands of the assistant surgeon and prevent fatigue, drift, and tremor which can impact the endoscopic view. Three-dimensional endoscopes will be available in the near future as well and rival the view afforded by the robot.

TORT is hampered by the size and cost of the surgical robot which has been limited to the Davinci Si and Xi (Intuitive Surgical, Inc., Sunnyvale, CA) to date. However, the newest generation single-port (Sp) may provide unparalleled access and maneuverability in the narrow confines of the working space. Furthermore, other surgical device companies are working on smaller and less expensive robots that will likely have applicability in TORT. One example is the Robotic ENT Microsurgery System (REMS) developed by Galen Surgical (Sunnyvale, CA) and Johns Hopkins University (Baltimore, MD). What is certain is that future technologic evolution will continue to lead to novel innovations in remote-access, “scarless” thyroid surgery.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned by the Guest Editors (Anuwong Angoon, Hoon Yub Kim, Ralph P. Tufano and Gianlorenzo Dionigi) for the series “Transoral Thyroidectomy” published in Annals of Thyroid. The article has undergone external peer review.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/aot.2017.11.01). The series “Transoral Thyroidectomy” was commissioned by the editorial office without any funding or sponsorship. Jeremy D. Richmon serves as an unpaid editorial board member of Annals of Thyroid from Jun 2017 to May 2019. Ralph P. Tufano served as the unpaid Guest Editor of the series. Dr. Tufano reports personal fees and other from Medtronic, personal fees from Hemostatix, outside the submitted work. The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the manuscript and ensure that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

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