Comparison of perioperative outcomes between gasless transaxillary endoscopic thyroidectomy and conventional open thyroidectomy for papillary thyroid carcinoma: a retrospective study.

Background: Papillary thyroid carcinoma (PTC) is the most common subtype of differentiated thyroid carcinoma. Gasless transaxillary endoscopic thyroidectomy (GUA) has been increasingly used because of its cosmetic advantages, but its perioperative outcomes compared with conventional open thyroidectomy (COT), particularly across different body mass index (BMI) categories, remain unclear. This study aimed to compare perioperative outcomes between GUA and COT and to explore the association between BMI and relevant perioperative indicators in patients with PTC. Methods: This single-center retrospective cohort study included 411 patients who underwent thyroid surgery at Huzhou Central Hospital between October 1, 2023 and October 1, 2024 and were pathologically confirmed as PTC. Patients were divided into the GUA group and the COT group according to surgical approach. According to the BMI criteria for Asian populations, patients were classified as underweight, normal weight, or overweight/obese. Clinical and perioperative data were collected and analyzed using Statistical Package for the Social Sciences (SPSS) version 27.0. Intergroup comparisons, correlation analyses, and multivariable binary logistic regression analyses were performed. Results: Among the 411 patients, 144 underwent GUA and 267 underwent COT. In both the normal-weight and overweight groups, operative time was significantly longer in the GUA group than in the COT group. In all BMI subgroups, postoperative drainage volume was significantly higher in the GUA group. In the normal-weight and overweight groups, the number of lymph nodes retrieved was significantly lower and hospitalization costs were significantly higher in the GUA group. Common postoperative complications were infrequent and comparable between the two groups across BMI strata, while cosmetic satisfaction tended to be higher after GUA. BMI showed only weak correlations with most perioperative indicators; however, in overweight patients, BMI was positively correlated with nodule size. Nodule size was independently associated with pathological N stage [odds ratio (OR) =1.097, 95% confidence interval (CI): 1.031-1.169, P=0.004]. Conclusions: Compared with COT, GUA was associated with longer operative time, greater postoperative drainage volume, higher costs, and fewer retrieved lymph nodes, but showed a comparable short-term safety profile in carefully selected patients. BMI was not an independent predictor of pathological N stage, but its association with nodule size in overweight patients suggests a possible relationship between body habitus and tumor burden. BMI, tumor characteristics, safety, cosmetic expectations, and medical cost should be considered when selecting the surgical approach for low-risk PTC.