A propensity score matching analysis of gasless endoscopic transaxillary thyroidectomy with five-settlement technique versus conventional open thyroidectomy in patients with papillary thyroid microcarcinoma

Background: In a previous study, we proposed a novel anatomy-based five-settlement method for transaxillary endoscopic thyroidectomy (fs-TAT) for patients with papillary thyroid carcinoma. The safety of this new method has been reported in a retrospective study of a single cohort. The safety and short-term oncological outcome of this method was confirmed by comparing it with conventional open surgery (COT) in patients with papillary thyroid microcarcinoma.

Methods: The medical records of patients who underwent fs-TAT or COT by a single surgeon from February 2019 to December 2021 were reviewed retrospectively. All patients were diagnosed with papillary thyroid microcarcinoma and underwent lobectomy and ipsilateral central compartment neck dissection. Propensity score matching was used to compare the technical safety and short-term oncologic outcomes of fs-TAT and COT for the purpose of reducing potential selection bias. Reporting was consistent with the STROCSS 2021 guidelines.

Result: After propensity score matching, 460 (fs-TAT: 230; COT: 230) patients remained in the study population. There were no significant differences in sex, age, tumor size, Hashimoto's thyroiditis, or tumor multifocality between the groups. The operative time was longer [104.5 (90.3, 120.0) vs. 62.0 (52.0, 76.0), P < 0.001] and the total postoperative drainage volume [135(90, 210) vs. 75 (55, 115), P < 0.001] was greater in the fs-TAT group than in the COT group. However, intraoperative bleeding [3.0 (2.0, 5.0) vs. 5.0 (5.0, 7.5), P < 0.001] was greater, and the median number of lymph nodes yielded [5.0 (2.3, 8.0) vs. 7.0 (5.0, 11.0), P < 0.001] was greater in the COT group than in the fs-TAT group. The groups exhibited no significant difference in the rate of complications (fs-TAT: 2.2% vs. COT: 2.6%, P = 0.856), rate of positive lymph nodes (fs-TAT: 32.2% vs. COT: 36.5%, P = 0.377), length of postoperative hospital stay (3 days vs. 3 days, P = 0.305) or total medical costs (26,936 vs. 26,549, P = 0.144).

Conclusion: Compared to conventional open surgery, fs-TAT offered excellent safety and acceptable short-term oncological outcomes in a selected cohort of patients with papillary thyroid microcarcinoma.