Share this article on:

A Systemic Review of Transoral Thyroidectomy

Shan, Liqun, MD*; Liu, Jianing, MD, PHD

Surgical Laparoscopy, Endoscopy & Percutaneous Techniques: June 2018 - Volume 28 - Issue 3 - p 135–138
doi: 10.1097/SLE.0000000000000512
Review Articles

Background: Transoral thyroidectomy is a kind of “natural orifice transluminal endoscopic surgery (NOTES)” which is now being performed in increasing frequency. However, the safety and feasibility have not been concluded yet.

Materials and Methods: A systemic literature search was performed in Pubmed, Cochrane, and Embase databases to identify all studies written in English and published up to April 2017. The keywords used were “transoral endoscopic,” “transoral robotic,” “oral vestibular endoscopic,” and “oral vestibular robotic” combined with “thyroidectomy” or “thyroid surgery.”

Results: Ten articles containing 211 cases matched the review criteria. The weighted average operative time was 119.9 minutes with an average intraoperative blood loss of 35.5 mL while the weighted average length of hospital stay was 4.0 days. The overall conversion rate to open surgery was 1.9%. An overall incidence rate of temporary hypoparathyroidism was 7.1%, temporary recurrent laryngeal nerve injury was 4.3%, whereas of mental nerve palsy was 4.3%.

Conclusions: According to those reviewed literatures, we can conclude that transoral thyroidectomy is safe and feasible in well-selected patients and offers good perioperative and postoperative outcomes.

Departments of *Surgery

Thyroid Surgery, The Second Hospital of Shandong University, Jinan, Shandong, China

The author declares no conflicts of interest.

Reprints: Jianing Liu, MD, PHD, Department of Thyroid Surgery, The Second Hospital of Shandong University, Jinan 250033, Shandong, China (e-mail: angela1943@126.com).

Received May 8, 2017

Accepted January 9, 2018

Thyroidectomy has become a standard surgical procedure in line with the experiences and developments of Emil Theodor Kocher1 since 1906. An open thyroidectomy leaves a noticeable scar on the anterior region of neck, which is considered disturbing, especially among young women. In recent years, minimally invasive surgery has being become more popular. Thanks to the development of endoscopic techniques and instruments, surgeons can perform a thyroidectomy from a remote site. Endoscopic thyroidectomy has evolved over the past 10 years in the pursuit of minimal invasion and avoiding scars on the neck. The existing approaches include axillary approach,2 the areola and cleavage approach,3 and the areola approach.4 Some surgeons consider that these approaches are not true minimal invasion because these approaches require more extensive tissue dissection in the chest and neck.

Natural orifice transluminal endoscopic surgery (NOTES) is gaining interest and has been termed an innovatory surgery as it allows surgeries without skin incisions.5 Transoral thyroidectomy (TOTE) fills the need for truly minimally invasive surgery and embodies minimally invasive principles.6 In 2008, Witzel et al7 attempted a hybrid procedure of thyroid surgery using a single access port with an accessory anterior neck port. Multiple articles about transoral thyroid surgery have been published since then. Wilhelm and Metzig8 was considered to be the first surgeon to perform transoral endoscopic thyroid surgery in clinical practice. In recent years, a rapid interest in this novel challenging approach was shown in the Asia-Pacific region due to its excellent cosmetic outcomes.9,10

In this study, we reviewed the literature published in English to evaluate the current status of TOTE. Meanwhile, the safety and feasibility of this procedure was also estimated.

Back to Top | Article Outline

MATERIALS AND METHODS

Literature Review

A systemic literature review was performed using the Pubmed, Cochrane, and Embase databases to identify all studies published up to April 2017. We searched this databases using the keywords “endoscopic transoral,” “robotic transoral,” “endoscopic oral vestibular,” ”robotic oral vestibular” combined with “thyroidectomy” or “thyroid surgery.”

Back to Top | Article Outline

Inclusion Criteria

Articles published in English containing >5 cases were included. Eligible articles must contain patient’s characteristics and perioperative outcomes. In the case of multiple publications from the same institution, only more informative study was chosen in our analysis in order to exclude data overlap. We also manually searched the bibliographies of the included studies avoiding omissive studies.

Back to Top | Article Outline

Exclusion Criteria

We excluded the following types of studies: single case reports, reviews, video or multimedia literature, studies referring to animals, technique reports, articles written in non-English, studies lacking original data.

Back to Top | Article Outline

Data Extraction

All the retrieved studies that met the inclusion and exclusion criteria were independently reviewed by 2 authors. The following variables were extracted from each study: the first author, country, publication year, number of patients, study population characteristics, perioperative outcomes (port incisions, operative time, blood loss, single or bilateral thyroidectomy, diagnosis, hospital stay, conversion rate), postoperative outcomes [Hypoparathyroidism, recurrent laryngeal nerve (RLN) injury, mental nerve palsy, wound infection, and other complications]. Discrepancies between the 2 reviewers were resolved by discussion and consensus.

Back to Top | Article Outline

RESULTS

Ten articles, involving 211 cases, were included in this review (Table 1). The flowchart of this review is shown in Figure 1. Wilhelm and Metzig8 was the first person performed a series of TOTE. Anuwong11 published an article with the largest number of cases in 2015. Major countries belonged to Asia-Pacific region.

TABLE 1

TABLE 1

FIGURE 1

FIGURE 1

Details on the age and sex of patients are listed in Table 2. The basic information of patients including age and sex was reported in 9 articles (n=203, 96.2%). The average age reported in 9 articles ranged from 24.0 to 54.9 years old, with a weighted average of 35.6 years old. The amount of female patients is 179 cases (88.2%).

TABLE 2

TABLE 2

Back to Top | Article Outline

Perioperative Outcomes

The review of perioperative outcomes were presented in Table 3. The location of incision is reported in 10 articles (n=211, 100%) and 9 authors (n=203, 96.2%) chose the oral vestibular area of the lower lip. The mean operative time, available in 10 studies, ranged from 60.4 to 265.4 minutes, with a weighted average of 119.9 minutes. Mean volume of intraoperative blood loss, reported in 7 articles (n=188, 89.1%), ranged from 11.1 to 97.0 mL, with a weighted average of 35.5 mL. Ninety-eight patients (46.4%) underwent single thyroidectomy. Details of pathologic diagnosis were presented in 9 articles (n=203, 96.2%). Overall, 22 patients were diagnosed with papillary carcinoma (10.4%) and the other 189 patients harbored benign lesions (89.6%). The average hospital stay days was reported in 8 articles (n=157, 74.4%), which ranged from 1.2 to 8.2 days, with a weighted average of 4.0 days. Two articles8,15 reported 4 cases (1.9%) converted to open surgery. The main reasons for conversion were technique and bleeding complications.

TABLE 3

TABLE 3

Back to Top | Article Outline

Postoperative Outcomes

The postoperative complications are listed in Table 4. The most common complications in transoral thyoidectomy are hypoparathyroidism, RLN injury, mental nerve palsy, and wound infection. Temporary hypoparathyroidism was reported in 4 articles11,14,15 and the overall incidence was 7.1%. Nine temporary RLN injuries were presented in 5 articles8,9,11,12,14 and the overall incidence was 4.3%. Only 1 case of permanent RLN injury occurred in this review. Mental nerve palsy was reported in 2 articles8,10 and the overall incidence was 4.3%. Two patients incurred wound infections. Other complications, including skin ecchymosis, emphysema, hematoma, skin pierced, and skin burn were reported in this review.

TABLE 4

TABLE 4

Back to Top | Article Outline

DISCUSSION

Thyroidectomy is one of the most common procedures performed in general surgery. Because of the advancement in surgical technique, the modifications, modernization, and development of the instruments including intraoperative neuromonitoring, and the assistance of optical magnifying devices,18,19 thyroidectomy is considered a safe procedure. Aside from the known complications including RLN palsy and hypoparathyroidism, the visible scar mark in the neck after conventional open thyroidectomy may lead to unpleasant consequence for the patients. Various approaches to endoscopic thyroidectomy2,20,21 have been developed in recent years, which can avoid the visible scar in anterior neck postsurgically. However, some surgeons think that these approaches do not comply with the ideology of minimally invasive surgery due to extensive dissection from a remote site. Since the natural orifice transluminal endoscopic surgery concept emerged in modern surgery, TOTE gained rapid development in recent years, requiring a shorter dissection tunnel compared with other approaches.

Several different approaches were invented during the development of transoral thyroid surgery including vestibular approach, sublingual access, and the combination of both. However, the sublingual access can bring structural and operative damage to the floor of the mouth. So the sublingual access is avoided and discontinued. Transoral vestibular approach is feasible and allows easy accessibility to the thyroid area. Meanwhile TOTE has less trauma, quicker postoperative wound healing and a lack of visible residual surgical scars. However, with this approach, surgeon requires an in depth knowledge in the anatomic structure of the operative area as the dissection is performed in the cranio-caudal direction which differs from open thyroidectomy.

Even though transoral thyroid surgery has left its infantile state, not all patients diagnosed with thyroid disease meet the criteria of this procedure. At present, the inclusion criteria are as follows: (1) benign tumor, such as single or multinodular goiter; (2) follicular neoplasm; (3) Graves’ disease; (4) thyroid papillary carcinoma without any evidence of metastasis.9,11,12 However, the most important criteria is that the patient is keen to pursue an optimal cosmetic result. Exclusion criteria comprised of patients who were as follows: (1) unfit for surgery; (2) had previous surgery or radiation in the area of neck; (3) evidence of tracheal/esophageal invasion or metastasis; (4) infected lesions like oral ulcers.10–12,14,17

A prolonged surgical time was noted in TOTE compared with open surgery. In the present study, the mean operative time ranged from 60.4 to 265.4 minutes, with a weighted average of 119.9 minutes. Intraoperative time for thyroid surgery is not less as extra time is needed to create the working space or port insertion. However, Cunchuan Wang10 reported that the average surgical time was 60.4 minutes which was much shorter than other authors. Lee22 believed that the learning curve should stabilize after 20 procedures. Therefore, the surgical time should be considered as an improbable factor. In this review, 22 patients were diagnosed with papillary carcinoma (10.4%), and the other 189 patients harbored benign lesions (89.6%). The central node of patients with papillary carcinoma was dissected in all articles. Four cases (1.9%) in this review were converted to open surgery because of technique and bleeding complications.

Hypoparathyroidism and RLN injury were the most common complications in thyroid surgery. The overall incidence of temporary hypoparathyroidism in this study was 7.1%. Fewins et al23 reported that the incidence rate of hypoparathyroidism in thyroid surgery was 6.9% to 46%. The overall incidence of temporary RLN injury was 4.3%. However, in conventional open thyroidectomy, the rates of transient and permanent RLN injury in the literature ranged from 2.11% to 11.8% and from 0.2% to 5.9%,24 respectively. Meanwhile, mental nerve palsy was reported in 2 articles8,10 published in 2011 and 2014 with an overall incidence of 4.3%. The mental foramen is most commonly located below and between the mandibular premolar, however the 2 lateral incisions were made in the vestibule near the premolars. Therefore, the mental nerve palsy may also occur in TOTE. So care must be taken to identify and avoid this nerve injury while making the lateral incisions. Concern for the infection occurrence arises due to the presence of the clean-contaminated wounds in transoral thyroid surgery. Therefore, in this study the patients who underwent this procedure were given prophylactic antibiotics to prevent wound infection due to clean-contamination wounds.

Conclusions based on the review of 10 articles with 211 cases suggest that TOTE is feasible and safe in selected patients. However, some pending questions about this procedure still remains which includes learning curve, long-term outcomes etc., which should be demonstrated. Therefore, specifically designed prospective randomized trials including standardization of outcome measures need to be performed to evaluate TOTE further.

Back to Top | Article Outline

REFERENCES

1. Hannan SA. The magnificent seven: a history of modern thyroid surgery. Int J Surg. 2006;4:187–191.
2. Ikeda Y, Takami H, Sasaki Y, et al. Endoscopic neck surgery by the axillary approach. J Am Coll Surg. 2000;191:336–340.
3. Ohgami M, Ishii S, Arisawa Y, et al. Scarless endoscopic thyroidectomy: breast approach for better cosmesis. Surg Laparosc Endosc Percutan Tech. 2000;10:1–4.
4. Wang C, Feng Z, Li J, et al. Endoscopic thyroidectomy via areola approach: summary of 1,250 cases in a single institution. Surg Endosc. 2015;29:192–201.
5. Clark MP, Qayed ES, Kooby DA, et al. Natural orifice translumenal endoscopic surgery in humans: a review. Minim Invasive Surg. 2012;33:189–296.
6. Karakas E, Steinfeldt T, Gockel A, et al. Transoral thyroid and parathyroid surgery. Surg Endosc. 2010;24:1261–1267.
7. Witzel K, von Rahden BH, Kaminski C, et al. Transoral access for endoscopic thyroid resection. Surg Endosc. 2008;22:1871–1875.
8. Wilhelm T, Metzig A. Endoscopic minimally invasive thyroidectomy (eMIT): a prospective proof-of-concept study in humans. World J Surg. 2011;35:543–551.
9. Nakajo A, Arima H, Hirata M, et al. Trans-oral video-assisted neck surgery (TOVANS). A new transoral technique of endoscopic thyroidectomy with gasless premandible approach. Surg Endosc. 2013;27:1105–1110.
10. Wang C, Zhai H, Liu W, et al. Thyroidectomy: a novel endoscopic oral vestibular approach. Surgery. 2014;155:33–38.
11. Anuwong A. Transoral endoscopic thyroidectomy vestibular approach: a series of the first 60 human cases. World J Surg. 2015;40:1–7.
12. Yang J, Wang C, Li J, et al. Complete endoscopic thyroidectomy via oral vestibular approach versus areola approach for treatment of thyroid diseases. J Laparoendosc Adv Surg Tech. 2015;25:470–476.
13. Udelsman R, Anuwong A, Oprea AD, et al. Trans-oral vestibular endocrine surgery: a new technique in the united states. Ann Surg. 2016;264:e13–e16.
    14. Jitpratoom P, Ketwong K, Sasanakietkul T, et al. Transoral endoscopic thyroidectomy vestibular approach (TOETVA) for Graves’ disease: a comparison of surgical results with open thyroidectomy. Gland Surg. 2016;5:546–552.
    15. Wang Y, Yu X, Wang P, et al. Implementation of intraoperative neuromonitoring for transoral endoscopic thyroid surgery: a preliminary report. J Laparoendosc Adv Surg Tech Part A. 2016;26:965.
    16. Yang K, Ding B, Lin C, et al. The novel transvestibule approach for endoscopic thyroidectomy: a case series. Surg Laparosc Endosc Percutan Tech. 2016;26:e25–e28.
      17. Dionigi G, Bacuzzi A, Lavazza M, et al. Transoral endoscopic thyroidectomy: preliminary experience in Italy. Update Surg. 2017;69:1–10.
      18. Nielsen TR, Andreassen UK, Brown CL, et al. Microsurgical technique in thyroid surgery—a 10-year experience. J Laryngol Otol. 1998;112:556–560.
      19. Dralle H, Sekulla C, Haerting J, et al. Risk factors of paralysis and functional outcome after recurrent laryngeal nerve monitoring in thyroid surgery. Surgery. 2004;136:1310–1322.
      20. Sasaki A, Nakajima JK, Otsuka K, et al. Endoscopic thyroidectomy by the breast approach: a single institution’s 9-year experience. World J Surg. 2008;32:381–385.
      21. Choi JY, Lee KE, Chung KW, et al. Endoscopic thyroidectomy via bilateral axillo-breast approach (BABA): review of 512 cases in a single institute. Surg Endosc. 2012;26:948–955.
      22. Lee HY, You JY, Woo SU, et al. Transoral periosteal thyroidectomy: cadaver to human. Surg Endosc. 2015;29:898–904.
      23. Fewins J, Simpson CB, Miller FR. Complications of thyroid and parathyroid surgery. Otolaryngol Clin North Am. 2003;36:189–206.
      24. Calò PG, Pisano G, Medas F, et al. Identification alone versus intraoperative neuromonitoring of the recurrent laryngeal nerve during thyroid surgery: experience of 2034 consecutive patients. J Otolaryngol Head Neck Surg. 2014;43:16.
      Keywords:

      transoral thyroidectomy; thyroid surgery; vestibular

      Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.