Abstract
BACKGROUND: The external branch of the superior laryngeal nerve (EBSLN) is susceptible to iatrogenic injury during thyroidectomy, which may lead to voice impairment. While intraoperative neuromonitoring (IONM) has been established for recurrent laryngeal nerve (RLN) protection, its application for identifying and preserving the EBSLN in gasless unilateral subclavian approach endoscopic thyroid surgery remains technically challenging and poorly documented. This study aims to evaluate the feasibility and safety of IONM for EBSLN exploration in this specific approach.
METHODS: In this retrospective cohort study, we analyzed 48 patients with papillary thyroid carcinoma who underwent modified gasless unilateral subclavian endoscopic hemithyroidectomy with central compartment dissection between October 2023 and June 2024. Feasibility was assessed by EBSLN identification rate, dissection time, and total operative time. Safety was evaluated by incidence of EBSLN-related complications, other surgical complications, and conversion rates.
RESULTS: The cohort included 39 females and 9 males, with a mean age of 35.4±10.4 years (19-59 years). The EBSLN was successfully identified in 46 cases (95.8%). Mean operative time was 115.6±25.1 minutes (60-165 minutes), with mean EBSLN dissection time of 3.4±1.0 minutes (2-6 minutes). Mean tumor size was 7.0±2.7 mm (3-16 mm). The mean number of harvested central compartment lymph nodes was 9.1±4.4 (3-21). The mean length of postoperative hospital stay was 2.9±0.7 days (2-5 days). All procedures were completed endoscopically without conversion. No EBSLN injuries, permanent RLN palsies, hemorrhages, or infections occurred.
CONCLUSIONS: IONM enables high-rate identification and safe preservation of the EBSLN in gasless subclavian endoscopic thyroid surgery. These findings support the integration of this technique into clinical practice to minimize EBSLN injury and improve functional outcomes in patients undergoing endoscopic thyroidectomy.