Defining the Thyroid-RLN Entry Triangle for Enhanced Recurrent Laryngeal Nerve Exposure in TOETVA: A Retrospective Study.

Background: Injury to the recurrent laryngeal nerve (RLN) and parathyroid glands (PGs) are the most common and serious complications during the transoral endoscopic thyroidectomy vestibular approach (TOETVA), and their exposure and protection are the most important factors affecting the operation time. Here, we report a novel anatomical landmark and surgical method to shorten the operative time and reduce the chance of injury to the RLN and PGs.

Methods: According to the different exposure methods of the RLN, patients were divided into the experimental group (from top to bottom, E-group) and the comparison group (from outside to inside, C-group), and 1:1 propensity score-matching (PSM) was performed. The demographics, operative data, postoperative data, and postoperative complications were analyzed by comparing the 2 groups.

Results: After PSM, a total of 206 patients were included. Except for tumor size, there were no significant differences between the 2 groups in terms of sex, age, body mass index, presence of Hashimoto's thyroiditis, or extent of surgery. Compared with the C-group, the operative time, in minutes, of the E-group was significantly shorter (hemithyroidectomy with central neck dissection (CND), C = 111.81 ± 25.83 vs E = 100.52 ± 16.47,  = .002 and bilateral thyroidectomy with CND, C = 177.87 ± 36.61 vs E = 156.05 ± 25.60,  = .004), the exposure time, in minutes, of the RLN was reduced (hemithyroidectomy with CND, C = 23.31 ± 7.07 vs E = 11.41 ± 2.75,  < .001 and bilateral thyroidectomy with CND, C = 45.64 ± 14.84 vs E = 21.76 ± 5.57,  < .001). The rate of postoperative temporary PGs and RLN injuries were also reduced (transient hypoparathyroidism, C = 13% vs E = 4%,  = .023 and transient RLN palsy, C = 10% vs E = 2%,  = .017). In addition, the remaining parameters such as the amount of bleeding, number of lymph node metastases, postoperative hospital stay, visual analog scale pain score, recurrence rate, and other complication rates were not significantly different between the 2 groups.

Conclusion: It is safe and feasible to construct Thyroid-RLN Entry Triangle (Peng's Triangle) for PGs and RLN protection in TOETVA. It is beneficial to shorten the operation time and reduce postoperative complications, both worthy of clinical promotion.

Trial Registration: This study was registered at the Chinese Clinical Trial Registry (UIN: ChiCTR2300067673, https://www.chictr.org.cn) in accordance with the World Medical Association's Declaration of Helsinki, 2013.