Transoral thyroidectomy vestibular approach versus non-transoral endoscopic thyroidectomy: a comprehensive systematic review and meta-analysis

Comparison of learning curves and related postoperative indicators between endoscopic and robotic thyroidectomy: a systematic review and meta-analysis

BACKGROUND

Endoscopic thyroidectomy (ET) and robotic thyroidectomy (RT) yield similar perioperative outcomes. This study investigated how the learning curve (LC) affects perioperative outcomes between ET and RT, identifying factors that influence the LC.

MATERIALS AND METHODS

Two researchers individually searched PubMed, EMBASE, Web of Science, and Cochrane Library for relevant studies published until February 2024. The Newcastle-Ottawa Scale assessed study quality. A random-effects model was used to compute the odds ratio and weighted mean difference (WMD). Poisson regression comparison of the number of surgeries (N LC ) was required for ET and RT to reach the stable stage of the LC. Heterogeneity was measured using Cochran's Q. Publication bias was tested using funnel plots, and sensitivity analysis assessed findings robustness. Subgroup analysis was done by operation type and patient characteristics.

RESULTS

This meta-analysis involved 33 studies. The drainage volume of ET was higher than that of RT (WMD=-17.56 [30.22, -4.49]). After reaching the N LC , the operation time of ET and RT was shortened (ET: WMD=28.15 [18.04-38.26]; RT: WMD=38.53 [29.20-47.86]). Other perioperative outcomes also improved to varying degrees. Notably, RT showed more refined central lymph node resection (5.67 vs. 4.71), less intraoperative bleeding (16.56 ml vs. 42.30 ml), and incidence of transient recurrent laryngeal nerve injury (24.59 vs. 26.77). The N LC of RT was smaller than that of ET (incidence-rate ratios [IRR]=0.64 [0.57-0.72]). CUSUM analysis (ET: IRR=0.84 [0.72-0.99]; RT: IRR=0.55 [0.44-0.69]) or a smaller number of respondents (ET: IRR=0.26 [0.15-0.46]; RT: IRR=0.51 [0.41-0.63]) was associated with smaller N LC . In RT, transoral approach (IRR=2.73 [1.96-4.50]; IRR=2.48 [1.61-3.84]) and retroauricular approach (RAA) (IRR=2.13 [1.26-3.60]; IRR=1.78 [1.04-3.05]) had smaller N LC compared to bilateral axillo-breast and transaxillary approach (TAA). In ET, the N LC of RAA was smaller than that of TAA (IRR=1.61 [1.04-2.51]), breast approach (IRR=1.67 [1.06-2.64]), and subclavian approach (IRR=1.80 [1.03-3.14]).

CONCLUSIONS

Rich surgical experience can improve surgical results of ET and RT. After reaching the N LC , the perioperative outcomes of RT are better than those of ET. Study subjects, surgical approaches, and analysis methods can affect N LC .

Application of fibrin sealant in drain-free transoral endoscopic thyroidectomy vestibular approach

Objective

The transoral endoscopic thyroidectomy vestibular approach (TOETVA) is a minimally invasive technique. This study aimed to compare the safety of TOETVA with fibrin sealant (Tisseel) and TOETVA with drainage.

Materials and Methods

Patients who underwent TOETVA between January 2018 and December 2021 were divided into drainage (n = 20) and Tisseel (n = 30) groups.

Results

The primary outcome was the incidence of complications. The secondary outcomes were operative time and postoperative pain. There were no significant differences in patient demographics, tumor size, intraoperative blood loss, and hospitalization days between the two groups. No patient required conversion to open thyroidectomy. The incidence of complications and postoperative pain was similar in the two groups. The operative time for TOETVA with Tisseel was significantly shorter than for TOETVA with drainage (P = 0.038).

Conclusion

TOETVA with Tisseel is a safe alternative to TOETVA with drainage, having a short operative time.

[Indications and technique for transoral thyroid gland and parathyroid gland surgery]

The conventional Kocher collar incision is the standard access to the thyroid and parathyroid glands. Although the incision length has been significantly shortened in recent years with this approach, there is increasing interest among patients in a surgical technique without visible scars in the décolleté. Transoral endoscopic thyroid gland surgery via the vestibular approach (TOETVA) is a modern technique that can be learned relatively quickly and leaves no visible scars because it is carried out exclusively through a natural orifice (natural orifice transluminal endoscopic surgery, NOTES). For retrieval of larger specimens, the transoral approach can be combined with a retroauricular access and thus covers a larger range of indications. The indications must be strictly followed, analogous to conventional surgery. Once the transoral access has been established, the operation is carried out as in open surgery but strictly from cranial to caudal. The classical complications are comparable to the results of conventional surgery. Specific complications include perioral, mandibular or cervical dysesthesia and hypesthesia.

Endoscopic thyroidectomy via chest-collarbone approach versus conventional open thyroidectomy: a retrospective comparative study

OBJECTIVE(S)

Endoscopic thyroidectomy, such as axillary, areola and transoral approaches, offer the advantage of a good cosmetic outcome, but it requires a wider dissection field compared to open thyroidectomy. Recently, chest-collarbone approach thyroidectomy has been widely developed in China because of its shorter anatomical route compared to other endoscopic approaches. This study retrospectively evaluated endoscopic thyroidectomy via chest-collarbone approach in patients with thyroid nodules to determine its feasibility.

METHODS

A total of 46 patients with thyroid disease who underwent endoscopic thyroidectomy between January 2022 and December 2022 were enrolled in the study and randomly matched to patients with thyroid disease who underwent open thyroidectomy at the same time based on nodule size and pathology. Postoperative bleeding, hoarseness situation, hospital stay, postoperative drainage volume, laryngeal nerve palsy, hypoparathyroidism and wound infection were assessed in both groups.

RESULTS

Forty-four patients underwent endoscopic thyroidectomy successfully and two patients changed to open thyroidectomy. The amount of postoperative drainage for the endoscopic thyroidectomy group was 102.78 ± 28.04 mL, and which was 71.91 ± 19.20 for open thyroidectomy group (p < 0.001). The postoperative hospital stay for the endoscopic thyroidectomy group was 8.78 ± 2.57 days, and which was 7.22 ± 1.13 for open thyroidectomy group (p < 0.001). There was no significant difference in postoperative bleeding, hoarseness situation, and wound infection between the two groups. Laryngeal nerve palsy, supraclavicular nerve injury and hypoparathyroidism were not observed in any patient during this study.

CONCLUSION

Chest-collarbone endoscopic thyroid surgery is acceptable. This treatment improves in a good cosmetic outcome in patients with thyroid disease. To assess patients with preoperative nodule size and nature of the case is the impact of the success rate, which is particularly important.

A Comparison Between the Transoral Endoscopic Thyroidectomy Vestibular Approach and the Transareolar Approach Regarding Perioperative Complications: A Systematic Review and Meta-Analysis

The global adoption of remote thyroidectomy is increasing, with the transoral endoscopic thyroidectomy vestibular approach (TOETVA) and transareolar approach (TAA) emerging as predominant methods. However, existing meta-analyses comparing these approaches to operative surgeries and short-term postoperative complications have significant limitations. To address this gap, our meta-analysis provides a comprehensive comparison between the TOETVA and TAA, focusing on operation time, intraoperative blood loss, postoperative drainage, and hospital stay duration. It aims to offer robust insights into their relative efficacy and safety profiles. We searched SCOPUS, PubMed, Web of Science, MEDLINE, and Cochrane Library from June 2015 to January 2024 for studies comparing transoral endoscopic thyroidectomy with the vestibular approach and areolar thyroidectomy using keywords, including "transoral thyroidectomy" and "scarless thyroidectomy." Studies were included if they were randomized controlled trials, case-control studies, or prospective/retrospective cohort studies comparing the TOETVA and TAA. Exclusion criteria removed case series, cross-sectional studies, editorials, non-English language, animal studies, and irrelevant articles. Data on operative time, postoperative drainage, intraoperative blood loss, and hospital stay were extracted. The Newcastle-Ottawa Scale was used to assess study quality (all studies scored 7-8). The findings revealed that the operative time was longer among the TOETVA group, with less intraoperative blood loss (odds ratio (OR) = 13.31, 95% confidence interval (CI) = 4.44-22.19); OR = -1.61, 95% CI = -2.82 to -0.39, respectively). Regarding hospitalization duration and postoperative drainage, no discernible difference was observed between the endoscopic TAA (ETAA) and TOETVA (OR = -0.04, 95% CI = -0.24 to 0.16; OR = -6.74, 95% CI = -20.08 to 6.60, respectively). The TOETVA has advantages over the TAA in terms of intraoperative blood loss and shorter operation times. However, both approaches exhibited comparable outcomes in terms of hospital stay duration and postoperative drainage. Furthermore, extensive randomized trials are warranted.

Comparison of surgical outcomes of transoral robotic and endoscopic thyroidectomy: A systematic review and network meta-analysis

This study aimed to compare surgical outcomes of transoral robotic thyroidectomy (TORT) and transoral endoscopic thyroidectomy vestibular approach (TOETVA), concurrently compared with conventional transcervical thyroidectomy (CTT). A network meta-analysis, comprising 23 studies, was performed in this study. The operative time of the CTT group was significantly shorter than that of the TOETVA and TORT groups. The hospital stay of the TOETVA group was significantly longer than that of the CTT group. Rates of transient recurrent laryngeal nerve palsy and total complications were higher in association with TOETVA than with TORT. No significant differences were found between the three groups in intraoperative blood loss, retrieved lymph nodes, postoperative pain, and other complications. Cosmetic satisfaction was significantly superior with TORT and TOETVA than with CTT. Compared with CTT, TOETVA and TORT showed superior cosmesis but no significant difference in surgical outcomes except for operative time and hospital stay.

Comparison of transoral vestibular robotic thyroidectomy with traditional low-collar incision thyroidectomy

Transoral vestibular robotic thyroidectomy can really make the patient's body surface free of scar. This study aimed to compare the surgical and patient-related outcomes between the transoral vestibular robotic thyroidectomy and traditional low-collar incision thyroidectomy. The clinical data of 120 patients underwent transoral vestibular robotic thyroidectomy (TOVRT) or traditional low-collar incision thyroidectomy (TLCIT) were collected from May 2020 to October 2021. Propensity score matching analysis was used to minimize selection bias. All these patients were diagnosed with papillary thyroid carcinoma (PTC) through ultrasound-guided fine-needle aspiration prior to surgical intervention and surgical plan was tailored for each patient. An intraoperative recurrent laryngeal nerve (RLN) detection system was used in all patients, whose RLNs were identified and protected. We performed transoral vestibular robotic thyroidectomy with three intraoral incisions. Additional right axillary fold incisions were adopted occasionally to enhance fine reverse traction of tissue for radical tumor dissection. Clinical data including gender, age, tumor size, BMI, operation time, postoperative drainage volume and time, pain score, postoperative length of stay (LOS),number of lymph nodes removed, complications, and medical expense were observed and analyzed. Propensity score matching was used for 1:1 matching between the TOVRT group and the TLCIT group. All these patients accepted total thyroidectomy(or lobectomy) plus central lymph node dissection and all suffered from PTC confirmed by postoperative pathology. No conversion to open surgery happened in TOVRT group. The operative time of TOVRT group was longer than that of TLCIT group (P < 0.05). The postoperative drainage volume of TOVRT group was more than that of TLCIT group (P < 0.05). The drainage tube placement time of TOVRT group were longer than that of TLCIT group (P < 0.05). Significant differences were also found in intraoperative bleeding volume, pain score and medical expense between the two groups (P < 0.05). The incidence of perioperative common complications such as hypoparathyroidism and vocal cord paralysis in the two groups was almost identical (P > 0.05). However, there were some specific complications such as surgical area infection (one case), skin burn (one case), oral tear (two cases), and paresthesia of the lower lip and the chin (two cases) were found in TOVRT group. Obviously, the postoperative cosmetic effect of the TOVRT group was better than TLCIT group (P < 0.05). TOVRT is safe and feasible for low to moderate-risk PTC patients and is a potential alternative for patients who require no scar on their neck. Patients accepted TOVRT can get more satisfaction and have less psychologic injury caused by surgery.

A modified, single-incision, gasless, endoscopic thyroidectomy and bilateral central neck dissection via axillary approach technique for bilateral papillary thyroid microcarcinoma: A preliminary report

Background

Our objective was to assess the viability and oncological security of a gasless, transaxillary single-incision endoscopic procedure for performing total thyroidectomy and bilateral central neck dissection (TT + BCND). This study focused on patients diagnosed with bilateral papillary thyroid microcarcinoma (PTMC).

Method

Between April 2020 and November 2021, 22 patients with bilateral PTMC underwent single-incision, gasless, transaxillary endoscopic TT + BCND. The patients' clinicopathologic characteristics, surgical completeness and complications were analyzed.

Result

Single-incision, gasless, transaxillary endoscopic TT + BCND was successful performed in all patients. The median (IQR) total surgical time was 143 (85-160) min. Only two patients experienced transient unilateral RLN palsy or transient hypocalcemia. All these complications resolved within 1 month after surgery. The median duration of hospital stay after surgery was 4 (3-4.5) days. The median hospitalization expense for these patients was 3848 (3781-4145) USD. The median number of lymph node yielded was 10.5 (8-15). The cosmetic outcomes were well-received by all individuals.

Conclusion

In certain cases, gasless, transaxillary endoscopic TT + BCND procedure performed through a single incision proved to be a secure alternative for managing bilateral PTMC.

Surgical methods of total thyroidectomy for differentiated thyroid cancer: a systematic review and Bayesian network meta-analysis

BACKGROUND

Emerging remote-access surgical methods are utilized to treat differentiated thyroid cancer. The study aimed to compare the surgical integrity, safety, efficacy, and postoperative experience of patients among common surgical methods.

METHODS

The PubMed, Medline, Cochrane Library, Web of Science, and EMBASE databases were searched from their inception until March 2023. Pairwise meta-analysis and Bayesian network meta-analysis were performed. The surface under the cumulative ranking curve (SUCRA) was used to illuminate the probability that each method would be the best for each outcome.

RESULTS

Thirty-two studies comprising 7042 patients were included. Robotic bilateral axillo-breast approach (RBABA) and robotic gasless transaxillary approach (RGAA) retrieved fewer lymph nodes (LNs) than open thyroidectomy (OT). RBABA showed a significantly lower permanent recurrent laryngeal nerve (RLN) palsy rate than OT. According to SUCRA values, endoscopic transoral approach (EOA) ranked the highest in retrieved LNs (0.84), the proportion of stimulated serum thyroglobulin less than 1.0 ng/ml (0.77), and the pain score (0.77). Endoscopic bilateral areola approach (EBAA) ranked the highest in the transient RLN palsy rate (0.72). The endoscopic gasless transaxillary approach (EGAA) ranked the highest in the transient hypoparathyroidism rate (0.78). RBABA ranked the highest in the rate of permanent RLN palsy (0.94) and hypoparathyroidism (0.77). OT ranked the highest in operative time (0.92).

CONCLUSIONS

Each surgical method of total thyroidectomy has benefits and limitations. EOA performed the best in maintaining surgical integrality and reducing the pain score, while taking a long operative time. Generally, RBABA showed the best advantage in protecting parathyroid glands and RLN but with the longest operative time. OT had the best advantage in operative time. Therefore, OT and EOA are ideal methods for patients with a higher risk of central LN metastasis. RBABA and EOA may not be suitable for elderly patients or those with high anesthesia risk.

Gasless endoscopic thyroidectomy via the anterior chest approach: the experience with 1500 cases

BACKGROUND

Conventional thyroidectomy leaves an eye-catching scar in the anterior neck region. Endoscopic thyroidectomy may achieve a better esthetic effect and improve quality of life postoperatively. The aim of this study was to undertake a complete review of a large cohort of the patients undergoing gasless endoscopic thyroidectomy (GET) via anterior chest approach (ACA) with a long-term follow-up period, and evaluate the results and limits of this procedure.

METHODS

Between 2003 and 2022, 1413 patients undergoing GET via ACA in our department were included. The demographic, clinicopathological characteristics, oncologic and esthetic outcomes were summarized and analyzed.

RESULTS

The indication for surgery was papillary thyroid carcinoma in 686 (48.5%) patients and benign thyroid diseases in 727 (51.5%) patients. Among them, 802 (56.8%) patients took hemithyroidectomy, and 611 (43.2%) patients did sub-total/total thyroidectomy. Meanwhile, 598 (42.3%) ones had central neck dissection, while 88 (6.2%) lateral neck dissection. The most common complication was transient hypoparathyroidism with an incidence of 2.9%. During the follow-up period of 2 to 232 months, three patients were confirmed locoregional recurrence. Most of the patients were satisfied with the cosmetic results.

CONCLUSION

Gasless endoscopic thyroidectomy via anterior chest approach is a safe and feasible procedure, which could achieve excellent oncologic and esthetic outcomes.

Transoral endoscopic thyroidectomy vestibular approach as a safe and feasible alternative to open thyroidectomy: a systematic review and meta-analysis

BACKGROUND

Transoral endoscopic thyroidectomy vestibular approach (TOETVA) is a scarless alternative to open thyroidectomy (OT). This systematic review and meta-analysis aimed to synthesize evidence comparing the intraoperative and postoperative outcomes of TOETVA and OT.

METHODS

A systematic literature search of PubMed, Web of Science, the Cochrane Library, and Google Scholar was performed to identify studies comparing the outcomes of TOETVA and OT published before February 2023. The outcomes of interest were operative time, intraoperative blood loss, hospital stay, postoperative pain, number of central lymph nodes retrieved, number of metastatic central lymph nodes, and incidences of transient and permanent recurrent laryngeal nerve injury, transient and permanent hypocalcemia, hematoma, and infection.

RESULTS

Thirteen studies published between 2016 and 2022, involving a total of 2889 patients (TOETVA, n =1085; OT, n =1804) were included in this systematic review and meta-analysis. Meta-analysis showed that the TOETVA group had a significantly longer overall operative time (weighted mean difference [WMD] 55.19; 95% CI, 39.15, 71.23; P <0.001), longer hospital stay (WMD, 0.27; 95% CI, 0.14, 0.39; P <0.001), and lower pain scores on postoperative day 1 (WMD, -1.41; 95% CI, -2.79, -0.03; P =0.04) than the OT group. Other intraoperative and postoperative outcomes were not significantly different between the groups.

CONCLUSION

TOETVA has a similar safety profile to OT with less postoperative pain, making it an appropriate and more cosmetically appealing alternative to OT for select patients.

The global status and hotspots of research in the field of trans-oral endoscopic thyroidectomy (TOET) from 2008 to 2022

Purpose

In this study, the aim was to comprehensively analyze the current status, hotspots, and trends of trans-oral endoscopic thyroidectomy (TOET) through bibliometric analysis and by presenting the field atlas.

Methods

Web of Science Core Collection database was adopted to screen studies regarding TOET published between January 1, 2008 and August 1, 2022. The evaluation covered the criteria total number of studies, keywords, and contributions from countries/regions, institutions, journals, and authors.

Results

A total of 229 studies were covered. SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES is the largest publication in the field of TOET. The three countries that contributed the most studies were Korea, China, and the USA. The most frequently occurring core keywords in the field of TOET are vestibular approach, outcomes, experience, safety, robotic thyroidectomy, scar, video-assisted thyroidectomy and quality-of-life. The seven clusters were generated in this study: intraoperative monitoring of the laryngeal return nerve (# 0), learning curve (# 1), postoperative quality of life (# 2), central lymph node dissection and safety (# 3), complications (# 4), minimally invasive surgery (# 5), and robotic surgery (# 6).

Conclusion

The main research topics in the field of TOET place focuses on learning curves, laryngeal nerve monitoring, carbon dioxide gas bolus, chin nerve injury, surgical complications, and surgical safety. In the future, more academics will focus on the safety of the procedure and reducing complications..

The ambulatory transoral endoscopic thyroidectomy vestibular approach is safe and economical for patients with thyroid nodules

BACKGROUND

Ambulatory thyroid surgery has been increasingly performed in recent years. However, the feasibility of the ambulatory transoral endoscopic thyroidectomy vestibular approach (TOETVA) has not been evaluated. We aimed to evaluate the safety, economy, and mental health outcomes of ambulatory TOETVA.

METHODS

We retrospectively reviewed the data of patients who underwent TOETVA between March 2019 and August 2022. The procedure was performed by a skilled surgical team from the Department of Thyroid Surgery of the affiliated Yantai Yuhuangding Hospital of Qingdao University. Patients were enrolled in the ambulatory (n=166) and conventional (n=290) groups, based on their chosen procedure. We analyzed patients' clinical characteristics, surgical outcomes, Hamilton Anxiety Rating Scale (HAM-A) scores, and hospitalization costs.

RESULTS

Of 456 patients, 166 underwent ambulatory TOETVA and 290 underwent conventional TOETVA. No significant differences were found in clinical and surgical characteristics between the groups, including sex (P=0.363), age (P=0.077), body mass index (P=0.351), presence of internal diseases (P=0.613), presence of Hashimoto's thyroiditis (P=0.429), pathology (P=0.362), maximum tumor diameter (P=0.520), scope of surgery (P=0.850), or operative time (P=0.351). There were no significant differences in maximum tumor diameter (P=0.349), extrathyroidal tissue invasion (P=0.516), number of retrieved central lymph nodes (P=0.069), or metastatic central lymph nodes (P=0.897) between the groups. No significant differences were found in complications, including transient hypoparathyroidism (P=0.438), transient vocal cord palsy (P=0.876), transient mental nerve injury (P=0.749), permanent mental nerve injury (P=0.926), and other complications (P=1.000). Ambulatory patients had shorter hospital stays (P<0.001) and reduced hospitalization costs (P<0.001). There was no significant difference in HAM-A scores between the groups (P=0.056).

CONCLUSIONS

Ambulatory TOETVA is a safe, feasible, and cost-effective procedure for selected patients. This procedure resulted in shorter hospital stays, decreased medical costs, and did not increase patient anxiety. To ensure patient safety, surgical teams must inform patients of the indications, when to seek help, and how to receive the fastest medical attention.

Completion thyroidectomy and lateral neck dissection revealed adhesions in the lateral neck compartment after gasless transaxillary endoscopic thyroidectomy: a case report

BACKGROUND

Endoscopic thyroidectomy is effective and safe surgical option for thyroid surgery while providing satisfactory cosmetic results. Gasless transaxillary endoscopic approaches have been reported to achieve endoscopic thyroidectomy in our center.

CASE DESCRIPTION

We present a patient who previously underwent gasless transaxillary endoscopic lobectomy with ipsilateral central neck dissection who underwent open completion thyroidectomy and lateral neck dissection (LND) (reoperation) in our center. The ultrasound test before the first treatment did not reveal abnormal lymph nodes in the central and lateral neck compartments. Further evaluation of the neck lymph nodes was not performed. Meanwhile, this patient did not participate in the originally planned follow-up at the 3- and 6-month visits. At the one-year visit, imaging tests revealed enlarged and suspicious malignant lymph nodes in levels III and IV of the lateral neck compartments. We believed that reoperation was performed for persistent, rather than truly recurrent disease for this patient. During the second surgery, we found that the surface of internal jugular vein (IJV) was significantly adhered to the surrounding fibroadipose tissue and the omohyoid muscle was adhered to the IJV. After carefully dissected the IJV, the dissection of the lateral neck compartment had been performed successfully.

CONCLUSIONS

Exposure of the lateral neck compartment in the gasless transaxillary procedure, especially exposure of the IJV, causes adhesions of the lateral neck compartment and brings difficulties for possible future LND. Gasless transaxillary endoscopic thyroid surgery should be performed in strictly selected patients with adequate preoperative assessment. The IJV should be carefully dissected to avoid IJV injury, and the lateral neck compartment could be dissected successfully during reoperation.

Learning curve and volume outcome relationship of endoscopic trans-oral versus trans-axillary thyroidectomy; A systematic review and meta-analysis

BACKGROUND

In the modern era, minimally invasive surgery is rapidly evolving and even replacing conventional open techniques in many surgical fields. Thyroidectomy was not an exception, with the introduction of multiple endoscopic thyroidectomy techniques. Trans-oral endoscopic trans-vestibular thyroidectomy (TOT) is a novel technique with promising outcomes. We conducted this meta-analysis to compare surgical outcomes and learning curves for TOT and other endoscopic thyroidectomy techniques.

METHODS

A systematic review in PubMed, MEDLINE, and EMBASE databases was conducted searching for publications on TOT versus trans-axillary thyroidectomy (TAT). The primary endpoint was operative (OR) time. Secondary endpoints were number of harvested lymph nodes (LNs), estimated blood loss (EBL), recurrent laryngeal nerve (RLN) injury, hoarseness, seroma, infection, chyle leak, hypocalcemia, hospital length of stay (LOS), and Cost. We also investigated the learning curve for each technique. Leave-out-out analysis, meta-regression, and subgroup analysis were used. Random effect inverse variance method was utilized.

RESULTS

Among 3820 retrieved studies, 15 studies (10 unmatched and 5 matched), with 2173 (TOT: 1024(47.12%) and TAT:1149(52.87%)) patients, met the inclusion criteria. The operative time and harvested L. Ns number were higher in TOT versus TAT (standard mean difference (SMD) = 0.72 [95%CI 0.07; 1.37], P = 0.029 and SMD = 0.32 [95%CI 0.02; 0.62], P = 0.036 respectively) while less EBL in TOT versus TAT (SMD = -0.26 [-0.43; -0.09], P = 0.0018). All other outcomes showed no significant difference between both groups. Weighted mean values for TOT and TAT were 158.03 vs 144.97 min for OR time, 6.33 vs 5.16 for harvested LNs, and $5,919.05 vs $6,253.79 for the cost. Statistical significance in learning curve development was noticed ranging between 6 and 15 annual cases.

CONCLUSION

Trans-oral thyroidectomy is a safe and reliable technique with outcomes comparable to other endoscopic techniques. It provides better access to the central compartment with a more feasible LN dissection. Improvement in surgical outcomes is expected with growing learning curve and technique mastery.

Comparison of Different Mandibular Jawlines Classifications on Transoral Endoscopic Thyroidectomy for Papillary Thyroid Carcinoma: Experiences of 690 Cases

BACKGROUND

The influences of patients' different mandibular jawlines on transoral endoscopic thyroidectomy via vestibular approach (TOETVA) have not been described before. The objective of this study was to introduce a new classification to assess different mandibular jawlines, and to evaluate the effects on TOETVA in terms of safety, feasibility, and postoperative feelings in the treatment of papillary thyroid carcinoma (PTC).

METHODS

The crossing angle of esthetic plane and mandibular plane was defined as Wang Angle, used to assess patients' different mandibular jawlines. Mandibular classifications of A (angle: 80° ~ 110°), B (angle > 110°), and C (angle < 80°) types were compared to evaluate the surgical outcomes of TOETVA by a retrospective study. 690 patients of PTC who received TOETVA were included in this study, which were divided into three groups according to mandibular classifications.

RESULTS

Clinicopathological characteristics of the patients including age, gender, body mass index, tumor size, Hashimoto thyroiditis were similar in the three groups. Patients' length of jay in group C was significantly longer than group A and group B (P < 0.01). The ratios of using suspension system in group C were significantly higher than group A and group B (P < 0.01). The scores of postoperative visual analogue scale (VAS) and ratios of mandibular swell in group C were significantly higher than group A and group B (P < 0.01). There was no significant difference in the three groups regarding surgical outcomes, including postoperative vocal cord paralysis, hypocalcemia, serum white blood cells and C-reactive protein levels.

CONCLUSIONS

The Wang angle and mandibular jawline classifications were firstly introduced in TOETVA. All the patients of class A, B, and C mandibular jawline can achieve safe and effective surgical outcomes in the treatment of PTC with TOETVA. Patients of class C need more assistance of suspension system, would experience higher scores of VAS, and higher ratios of mandibular swell compared with class A and B.