[Evaluation of safety and efficacy of endoscopic thyroidectomy via sternocleidomastoid muscle posteroinferior approach].

Objective: To evaluate the clinical efficacy and safety of endoscopic thyroidectomy via sternocleidomastoid muscle posteroinferior approach (ETSPIA). Methods: A retrospective analysis was conducted on the clinical data of 213 patients with thyroid lesions who underwent ETSPIA in the Thyroid and Head and Neck Surgery Department of Beijing Tongren Hospital from November 2022 to December 2024. The cohort included 64 males and 149 females, aged from 11 to 69 years. Among them, 188 cases were diagnosed with papillary thyroid carcinoma (PTC), and 25 cases presented with benign thyroid lesions. The clinical data included operative time, intraoperative blood loss, postoperative changes in parathyroid hormone (PTH) and calcium ion levels, complications, lymph node metastasis, and follow-up outcomes. Statistical analysis was performed using descriptive methods with SPSS version 26.0. Results: All 213 patients were successfully completed unilateral thyroid lobectomy combined with central compartment lymph node dissection, with or without lateral neck dissection. The median operative time was 3 hours and 43 minutes, with a median intraoperative blood loss of 10 ml and a median postoperative hospital stay of 4 days. The median follow-up duration was 26 months, and no patients reported anterior neck discomfort, such as pressure or swallowing-related pulling sensations. Two patients experienced chyle leakage, which resolved after standardized treatment, and twelve patients reported mild numbness behind the ears, which subsided within one month. No cases of transient recurrent laryngeal nerve injury leading to hoarseness were observed. Postoperative parathyroid function remained intact, with a slight increase in PTH levels observed three months postoperatively in patients with papillary thyroid carcinoma and benign thyroid lesions. Postoperative pathology revealed occult lateral cervical lymph node metastases in 39 cases. Conclusion: ETSPIA offers advantages in postoperative recovery and cosmetic outcomes while effective resections of tumors and metastatic lymph nodes. This novel endoscopic approach combines the benefits of minimally invasive surgery with functional preservation, making it a promising technique for thyroid surgery.