The safety of transoral periosteal thyroidectomy: results of Swine models

Minimally Invasive Neck Surgery: An Animal Model Study

Background: Minimally invasive surgery (MIS) is replacing conventional surgery as the "gold standard" in different surgical areas. Although cervical MIS is already accepted in the adult population, its use in children is still new and controversial. The natural obstacles to this approach are the absence of a natural cavity, with the inherent complications of creating one artificially, and the limited existing workspace especially in pediatric patients. All endoscopic techniques in the field of neck surgery try to live up to the high cosmetic expectations and the transoral cervical approach as a natural orifice surgery technique excels at it. Aim: Besides the goal of feasibility, we aim to report on the pitfalls of this approach, by using an experimental rabbit model for minimally invasive thyroidectomy. Materials and Methods: Transoral endoscopic thyroidectomies using a vestibular approach were performed in 10 anesthetized rabbits. All surgeries were video recorded. The surgical time, anatomy identified, difficulties, and intraoperative complications were documented. Results: Through one trocar in the vestibular area and two lateral stab incisions, it was possible to create a working space and to reach the peritracheal area. Total thyroidectomies were completed in the 10 animals with a mean operative time of 51 minutes. In all of them we were able to identify the fascial spaces of the neck and the major vessels. During surgery, the lack of space required surgical gestures to be very precise, soft, and gentle. There were 2 cases with a small amount of bleeding and one mild trachea laceration during the procedure, but none of them required suspension or conversion to an open procedure. Animals were euthanized immediately after the surgical procedure. Conclusions: The vestibular approach seems to be a feasible technique to access pediatric neck pathology. Despite the differences in the cervical anatomy, the limited workspace of the rabbit model perfectly matches the requirements of a pediatric training model.

Current concepts in thyroid gland surgery: transoral endoscopic and robotic surgical procedures

The increased incidence of thyroid cancer in young females may raise concerns about visible hypertrophic scarring on the center of the neck after thyroid gland surgery. Therefore, endoscopic surgical procedures have attracted significant interest from patients with thyroid cancer, leading to the development of various endoscopic and robotic approaches. Although the cosmetic outcomes of current endoscopic and robotic thyroid surgeries have been excellent, all the procedures still require a large incision and extensive flap elevation. Transoral endoscopic thyroid surgery is a newly developed surgical method performed by inserting an endoscope through a mucosal opening created in the mouth, obviating the need for a skin incision. Additionally, the dissection area is relatively small and no dressings are required. Showering or shaving may resume the day after surgery and the port created within the oral mucous membrane generally heals within one week. Importantly, this approach is markedly less invasive than other endoscopic approaches. Although transoral endoscopic thyroid surgery has not yet been universally accepted, it may emerge as the preferred method for thyroid surgery in the near future.

Minimally Invasive Approaches for Thyroid Surgery-Pitfalls and Promises

PURPOSE OF REVIEW

To provide an overview of the feasibility and safety of current minimally invasive remote-access approaches for thyroid surgery, in view of the amounting new challenges and paradigm shifts in the management of thyroid pathologies.

RECENT FINDINGS

Over the past two decades, several remote-access approaches for thyroid surgery have been developed to improve cosmesis; however, none has been widely adopted extensively in the Western world. The recently emerged transoral endoscopic thyroidectomy via vestibular approach (TOETVA) is the only true minimally invasive approach, completely avoiding skin incisions. It has a relatively short learning curve, midline surgical view, accessible surgical equipment, and relatively broad inclusion criteria with promising surgical outcomes as reported to date. TOETVA has proven to be safe and feasible for carefully selected patients. Further experience and long-term follow-up are needed to define the added value of TOETVA except for improved cosmetic outcome.

Institutional experience of 200 consecutive papillary thyroid carcinoma patients in transoral robotic thyroidectomy surgeries

BACKGROUND

We evaluated the outcomes of patients with papillary thyroid carcinoma (PTC) who underwent transoral robotic thyroidectomy (TORT).

METHODS

We retrospectively analyzed the perioperative outcomes of 200 patients (170 women and 30 men) with PTC who underwent TORT at a single center between March 2016 and February 2018.

RESULTS

There were 182 and 13 cases of lobectomy and total thyroidectomy, respectively, with corresponding mean operative times of 200.6 ± 31.2 and 265.7 ± 63.0 minutes. On average, 5.6 ± 3.45 lymph nodes were retrieved per patient. There were 12 cases of perioperative morbidity. No conversion to endoscopic or conventional open surgery was noted. In a subgroup analysis for predictors of difficult TORT, patient sex was the only factor showing a significant operative time difference between a difficult and a nondifficult thyroidectomy.

CONCLUSION

TORT can be performed safely in patients with PTC without serious complications.

Indications, benefits and risks of transoral thyroidectomy

The advancement of minimally invasive surgery in the field of endocrine surgery over the last 2 decades has fostered the attempt of natural orifice transluminal endoscopic surgery (NOTES) for thyroidectomy and parathyroidectomy via oral incisions. This technically demanding surgery is currently being evaluated in a number of specialised centres. The procedure has gained popularity worldwide and is performed in more than 50 centres. By retrieving information from published or presented articles and direct personal communications, this study reports several issues to enable and optimise correct patient and surgeon candidacy, present the advantages and prevent novel complications under the standards of open thyroid surgery. Not all patients are eligible for the transoral approach. Transoral endoscopic and robotic procedures were described and critically analysed in this study.

Transoral Robotic Thyroidectomy for Papillary Thyroid Carcinoma: Perioperative Outcomes of 100 Consecutive Patients

BACKGROUND

Endoscopic transoral thyroidectomy is a recently introduced technique of remote access thyroidectomy. We previously reported the feasibility of the robotic approach (TORT). Nevertheless, experience to date is limited, with scant data on outcomes in patients with papillary thyroid carcinoma (PTC).

METHODS

This was a retrospective analysis of prospectively collected data. Patients with PTC, who underwent TORT at a single center between March 2016 and February 2017, were analyzed.

RESULTS

There were a total of 100 patients (85 women, 15 men) with a mean age of 40.7 ± 9.8 years, and a mean tumor size of 0.8 ± 0.5 cm. Nine patients underwent a total thyroidectomy, and 91 underwent a lobectomy. The operative time for a total thyroidectomy and lobectomy was 270.0 ± 9.3 and 210.8 ± 32.9 min, respectively. Ipsilateral prophylactic central neck compartment dissection was performed routinely with retrieval of 5.0 ± 3.6 lymph nodes. Perioperative morbidity was present in nine patients including transient recurrent laryngeal nerve palsy (n = 1), postoperative bleeding requiring surgical intervention (n = 1), zygomatic bruising (n = 2), chin flap perforation (n = 1), oral commissure tearing (n = 2), and chin dimpling (n = 2). There was no conversion to endoscopic or conventional open thyroid surgery.

CONCLUSION

In this study, TORT could be safely performed in a large series of patients with PTC without serious complications. In selected patients, TORT by experienced surgeons could be considered an alternative approach for remote access thyroidectomy.

A surgical and anatomo-histological study on Transoral Endoscopic Thyroidectomy Vestibular Approach (TOETVA)

BACKGROUND

The number of TOETVA surgeries has increased worldwide but the anatomical passage of trocars is not clearly defined. We aimed to define detailed surgical anatomical passage of the trocars in cadavers. The incisions in oral vestibule, anatomical pathways of trocars, affected mimetic muscles, neurovascular relations of trocars and histological correlation of surgical anatomy were investigated.

METHODS

Four cadavers and 6 six patient oral vestibules were used. The locations of optimised vestibular incisions were measured photogrammetrically. Initial steps of TOETVA surgery were performed on cadavers according to those optimal incisions. TOETVA preformed cadavers dissected to determine anatomical passages of the trocars. Afterwards, flap of lower lip and chin were zoned by software appropriate to the trocars routes. Histological analyses of the zones were made in correlation with dissections.

RESULTS

Mimetic muscles associated with median (MT) and lateral trocars (LT) are orbicularis oris, mentalis, depressor anguli oris, depressor labii inferioris and platysma muscles. Trocars affect mimetic muscles in the perioral, chin and submental regions in different ways. The risk of mental nerve injury by MT is low. LT pass through the DLI muscle. The transmission of LT to the subplatysmal plane in the submental regions can be in two different ways. The arterial injury risk is higher with LT than the MT.

CONCLUSIONS

The surgical anatomy of the perioral, chin and submental regions for the initial TOETVA steps has been defined. Detailed surgical anatomical passages of the MT and LT were determined. Anatomical pattern to reach subplatysmal plane are presented. Mimetic muscles effected by trocars were determined. Endocrine surgeons should know the anatomical passage of TOETVA trocars.

Robotic transoral thyroidectomy: Total thyroidectomy and ipsilateral central neck dissection with da Vinci Xi Surgical System

BACKGROUND

Transoral approach for thyroidectomy draws attention recently among the thyroid surgeons, with the merits of cosmetic outcomes and minimal flap dissection. The aim of this study is to demonstrate the details and the steps of transoral robotic thyroidectomy.

METHODS

We made three incisions in the gingival-buccal sulcus for three 8-mm intraoral ports: one inverted U-shaped 1-cm midline incision approximately 2 cm above the frenulum, and two 0.5-cm lateral incisions near the commissure of lips. An additional 8-mm axilla port was inserted for countertraction and later drain insertion.

RESULTS

Right thyroid lobectomy, ipsilateral central neck dissection, and left thyroid lobectomy were performed with preserving recurrent laryngeal nerves and parathyroid glands. There was no development of transient or permanent hypoparathyroidism, vocal cord palsy, postoperative bleeding, or surgical site infection.

CONCLUSION

Transoral robotic total thyroidectomy and ipsilateral central neck dissection using the da Vinci Xi Surgical System are feasible and safe.

Lessons Learned From a Faulty Transoral Endoscopic Thyroidectomy Vestibular Approach

BACKGROUND

Transoral endoscopic thyroidectomy via vestibular approach (TOETVA) is currently considered the most promisingly scarless approach to the thyroid and has gained more acceptance.

MATERIALS AND METHODS

We described a case of faulty TOETVA.

RESULTS

The faulty TOETVA resulted in pneumomediastinum, diffuse subcutaneous emphysema, prolonged surgery, and anesthesia.

CONCLUSIONS

The important technical considerations during TOETVA, including the use of external retraction, the identification of the subplatysmal plane of dissection, CO2 insufflation settings, the learning curve, and patient selection, were described and discussed.

Transoral Endoscopic Thyroidectomy: A Systematic Review of the Practice So Far

Background and Objectives

Thyroid disease largely affects young females, but the incidence is also increasing among males. In an effort to avoid the scarring of the neck that is synonymous with conventional thyroidectomy, endoscopic techniques have been developed over the years. The transoral endoscopic approach is the latest of these innovations that promises a scarless surgical outcome. This review evaluates whether this technique is safe and feasible in live patients and outlines the outcomes in published literature so far.

Database

PubMed, Medline, BioMed Central, Cochrane Library, OVID and Web of Science were systematically searched by using a Medical Subject Heading (MeSH)-optimized search strategy. The selection of papers followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines after setting strict inclusion and exclusion criteria. Sixteen studies were included in the final analysis.

Discussion

This systematic review presents cases of 785 patients. Surgeons in 15 of the studies used a completely vestibular approach, whereas those in the remaining 2 used the floor of the mouth for primary access. Conversion to open surgery took place in 1.3%. In total, 4.3% of patients experienced transient laryngeal nerve palsy, whereas 0.1% had permanent recurrent incidences of the condition. Transient hypocalcemia occurred in 7.4% of cases, with no recorded permanent cases. Carbon dioxide embolism occurred in 0.6% of cases, and another 0.6% had a deep-seated neck infection. The complication rates within the review were deemed acceptable and the overall technique feasible. A prospective randomized controlled trial was proposed to compare this technique with conventional thyroidectomy.

Feasibility of Continuous Intraoperative Neural Monitoring During Transoral Endoscopic Thyroidectomy Vestibular Approach in a Porcine Model

Background: Experimental study to evaluate feasibility of continuous intraoperative neural monitoring (C-IONM) in transoral endoscopic thyroidectomy vestibular approach (TOETVA). Methods: Duroc-Landrace pigs were orally intubated with electromyogram endotracheal tube. Automatic periodic stimulation (APS) electrode was allocated in the operative field through the 5-mm ports. APS was then repose on vagal nerve (VN) with different approaches: (1) median, that is, between sternothyroid and thyroid gland; and (2) lateral, that is, between sternocleidomastoid and sternothyroid. VN was stimulated proximally and distally to the APS location to verify whether the dissection and/or placement determined VN injury. Video presentation is offered. Results: Assembled APS accessory was feasible in large-brained animals. The two basic options for VN approaches were tested. Baseline obtained had amplitude values >1000 μV, bilaterally. Conclusions: C-IONM was feasible in TOETVA in porcine models, but simplification of electrode design and application is needed.

Monitored transoral endoscopic thyroidectomy via long monopolar stimulation probe

This video aimed to describe the role of intraoperative neuromonitoring (IONM) during transoral endoscopic thyroidectomy vestibular approach (TOETVA) with emphasis given to IONM technical and technological notes, the identification of recurrent laryngeal nerve (RLN). Standardized technique of IONM consist in identifying and monitoring both the vagus nerve and the RLNs before and after resection (V1, V2, R1, R2). According to this report, IONM during TOETVA is feasible and safe in providing identification and function of laryngeal nerves. IONM enable surgeons to feel more comfortable with their initial approach to TOETVA or extended indications. Larger series are needed for appropriated evaluation of IONM in reduction of the rates for RLN complications.

Robotic and endoscopic transoral thyroidectomy: feasibility and description of the technique in the cadaveric model

Background

Numerous new approaches have been described over the years to improve the cosmetic outcomes of thyroid surgery. Transoral approach is a new technique that aims to achieve superior cosmetic outcomes by concealing the incision in the oral cavity.

Methods

Transoral thyroidectomy through vestibular approach was performed in two institutions on cadaveric models. Procedure was performed endoscopically in one institution, while the robotic technique was utilized at the other.

Results

Transoral thyroidectomy was successfully performed at both institutions with robotic and endoscopic techniques. All vital structures were identified and preserved.

Conclusions

Transoral thyroidectomy has been performed in animal and cadaveric models, as well as in some clinical studies. Our initial experience indicates the feasibility of this approach. More clinical studies are required to elucidate its full utility.

Transoral thyroidectomy: advantages and limitations

In this opinion paper of the Journal of Endocrinological Investigation, leading experts in the field report on their current clinical experience with a novel approach for thyroid gland surgery, namely, "transoral thyroidectomy" (TOT). This feasible and novel surgical procedure does not require visible incisions and is, therefore, a truly scarless surgery. Patients meeting the following criteria can be considered as candidates for TOT: (a) an ultrasonographically (US) estimated thyroid diameter ≤10 cm; (b) US-estimated gland volume ≤45 mL; (c) nodule size ≤50 mm; (d) presence of a benign tumor such as a thyroid cyst or a single- or multi-nodular goiter; (e) Bethesda 3 and/or 4 category and (f) papillary microcarcinoma without the evidence of metastasis. The procedure is conducted via a three-port technique at the oral vestibule using a 10-mm port for the 30° endoscope and two additional 5-mm ports for the dissecting and coagulating instruments. TOT is performed using conventional endoscopic instruments and is probably the best scarless approach to the thyroid because of the short distance between the thyroid and the incisions placed intra-orally that do not result in any cutaneous scar and upon following the surgical planes. Experts in TOT organized a working group of general, endocrine, head and neck ENT surgeons and endocrinologist to develop the standards for practicing this emerging technique.

Transoral robotic thyroidectomy (TORT): procedures and outcomes

Remote-access approaches to the thyroid gland have seen a rapid evolution recently with the development of various techniques to minimize the cosmetic and quality-of-life impact of a visible scar. Most approaches have required significantly more tissue dissection and have been limited in their extent to treat contralateral disease. The transoral approach is the most recent iteration of "scarless" thyroidectomy and offers various advantages over other techniques including less tissue dissection, equal access to both sides of the neck, and a superb midline view of the anatomy. Transoral thyroidectomy may be performed with either laparoscopic or robotic technology, each with various advantages and disadvantages. Herein, we discuss our experience with transoral robotic thyroidectomy (TORT).

Transoral thyroidectomy: why is it needed?

Transoral thyroidectomy (TOT) represents reasonably the desirable minimally invasive approach to the gland due to the scarless non-visible incisions, the limited distance between the gland and the access that minimize tissue dissection and respect of the surgical anatomical planes. Patients are routinely selected according to an extensive inclusion criteria: (I) ultrasonographically (US) estimated thyroid diameter not larger than 10 cm; (II) US gland volume ≤45 mL; (III) nodule size ≤50 mm; (IV) a benign tumor, such as a thyroid cyst, single-nodular goiter, or multinodular goiter; (V) follicular neoplasm; (VI) papillary microcarcinoma without lymph node metastasis. The operation is realized through median, central approach which allows bilateral exploration of the thyroid gland and central compartment. TOT is succeed both endoscopically adopting ordinary endoscopic equipments or robotically. In detail three ports are placed at the inferior oral vestibule: one 10-mm port for 30° endoscope and two 5-mm ports for dissecting, coagulating and neuromonitoring instruments. Low CO₂ insufflation pressure is set at 6 mmHg. An anterior cervical subplatysmal space is created from the oral vestibule down to the sternal notch, laterally to the sterncleidomuscles similar to that of conventional thyroidectomy. TOT is now reproducible in selective high volume endocrine centers.

Transoral endoscopic thyroidectomy: preliminary experience in Italy

Transoral endoscopic thyroidectomy vestibular approach (TOETVA) is a feasible novel surgical procedure that does not need visible incisions. We describe our initial experience with TOETVA. We recruited 15 patients who were willing to undergo TOETVA. Inclusion criteria were (a) patients who had a neck ultrasound (US) with a estimated thyroid diameter not larger than 10 cm; (b) US estimated gland volume ≤45 mL; (c) nodule size ≤50 mm; (d) a benign tumor, such as a thyroid cyst, single-nodular goiter, or multinodular goiter; (e) follicular neoplasm; (f) papillary microcarcinoma without evidence of metastasis. The procedure is carried out through a three-port technique placed at the oral vestibule, one 10-mm port for 30° endoscope and two additional 5-mm ports for dissecting and coagulating instruments. CO₂ insufflation pressure is set at 6 mmHg. An anterior cervical subplatysmal space is created from the oral vestibule down to the sternal notch, laterally to the sternocleidomastoid muscle. Thyroidectomy is done fully endoscopically using conventional endoscopic instruments and intraoperative neuromonitoring. There were 34% total thyroidectomies and 66% hemithyroidectomies. All TOETVA procedures were performed successfully with no conversions. The mean operative time was 87.6 (59-118) min for lobectomy and 107.6 (99-135) min for bilateral procedure. We observed one case of transient postoperative hypocalcemia. There was no recurrent laryngeal nerve palsy. The cosmetic result was excellent in all patients. This is the first case series of TOETVA in Italy. TOETVA may provide a method for ideal cosmetic results. The results are encouraging, and we are optimistic about the future expansion of its applicability.

Transoral robotic thyroidectomy: a preclinical feasibility study using the da Vinci Xi platform

Transoral thyroid surgery allows the surgeon to conceal incisions within the oral cavity without significantly increasing the amount of required dissection. TORT provides an ideal scarless, midline access to the thyroid gland and bilateral central neck compartments. This approach, however, presents multiple technical challenges. Herein, we present our experience using the latest generation robotic surgical system to accomplish transoral robotic thyroidectomy (TORT). In two human cadavers, the da Vinci Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA) was used to complete TORT. Total thyroidectomy and bilateral central neck dissection was successfully completed in both cadavers. The da Vinci Xi platform offered several technologic advantages over previous robotic generations including overhead docking, narrower arms, and improved range of motion allowing for improved execution of previously described TORT techniques.

Transoral endoscopic thyroidectomy via vestibular approach: operative steps and video

In this video we describe transoral endoscopic thyroidectomy vestibular approach (TOETVA). Inclusion criteria are (I) patients who had a ultrasonographically (US) estimated thyroid diameter not larger than 10 cm; (II) US estimated gland volume ≤45 mL; (III) nodule size ≤50 mm; (IV) a benign tumor, such as a thyroid cyst, single-nodular goiter, or multinodular goiter; (V) follicular neoplasm; (VI) papillary microcarcinoma without evidence of metastasis. The procedure is carried out through three-port technique placed at the oral vestibule, one 10-mm port for 30° endoscope and two additional 5-mm ports for dissecting and coagulating instruments. CO₂ insufflation pressure is set at 6 mmHg. An anterior cervical subplatysmal space is created from the oral vestibule down to the sternal notch, laterally to the sterncleidomuscles. Thyroidectomy is done fully endoscopically using conventional endoscopic instruments and intraoperative neuromonitoring (IONM).

Transoral robotic thyroid surgery

There is currently significant demand for minimally invasive thyroid surgery; however the majority of proposed surgical approaches necessitate a compromise between minimal tissue dissection with a visible cervical scar or extensive tissue dissection with a remote, hidden scar. The development of transoral endoscopic thyroid surgery however provides an approach which is truly minimally invasive, as it conceals the incision within the oral cavity without significantly increasing the amount of required dissection. The transoral endoscopic approach however presents multiple technical challenges, which could be overcome with the incorporation of a robotic operating system. This manuscript summarizes the literature on the feasibility and current clinical experience with transoral robotic thyroid surgery.