The Impact of Body Mass Index on Safety and Efficacy of Endoscopic Radical Thyroidectomy via Gasless Unilateral Axillary Approach for Thyroid Cancer Patients.

Aim: To evaluate the safety and efficacy of endoscopic radical thyroidectomy via the gasless unilateral axillary approach (GUAA) for thyroid cancer patients across different body mass index (BMI) categories.

Methods: A total of 333 patients with papillary thyroid carcinoma who underwent GUAA unilateral thyroidectomy and central lymph node dissection between June 2021 and February 2023 were retrospectively analyzed. The patients had been followed up for at least longer than 1 year. Patients were stratified into four groups based on their BMI: Group 1 (control group, 18.5 ≤ BMI < 24), Group 2 (BMI <18.5), Group 3 (24 ≤ BMI < 28), and Group 4 (BMI ≥28). The Group 3 and 4 defined as high BMI group while Group 1 defined as low BMI. The surgical-related indicators, operative time, numbness in the supraclavicular area, and rates of complication incidence between the four groups were compared.

Results: There were no significant differences among the groups in terms of age, sex, tumor location (left or right), number of central lymph node dissections, central lymph node metastasis rates, total drainage volume, or postoperative hospital stay (p > 0.05). However, patients with higher BMI experienced significantly longer operative time compared to the control group (128.14 ± 38.69 min [Group 3], 142.17 ± 37.92 min [Group 4] vs. 114.33 ± 38.79 min [Group 1], p < 0.05). The incidence of complications-including recurrent laryngeal nerve (RLN) palsy, incision infection, and postoperative bleeding-did not differ significantly among groups. However, patients with low BMI (Group 1) had a significantly higher incidence of supraclavicular numbness compared to the Group 2 (56.25% vs. 8.04%, p < 0.05).

Conclusions: Endoscopic thyroidectomy via gasless unilateral axillary approach is a safe surgical option for patients with thyroid cancer. High BMI is associated with longer operative time but does not increase complication rates. The average surgical duration for obese patients is approximately 28 minutes longer than that for patients with normal weight. Patients with low BMI require particular attention to the protection of the supraclavicular nerve to reduce the risk of postoperative numbness.