Comparative study of bilateral axillo-breast approach endoscopic and robotic thyroidectomy: propensity score matching analysis of large multi-institutional data.

Purpose: The aim of this study was to compare the large multi-institutional data of surgical outcomes of bilateral axillo-breast approach (BABA) robotic (RT) and endoscopic thyroidectomy (ET) and to evaluate the merits of robotic thyroidectomy. Methods: From 2004 to 2015, 1,029 patients underwent BABA ET, and from 2008 to 2015, 2003 patients underwent BABA RT in 3 large volume centers in Korea. Two groups were retrospectively compared in terms of clinicopathologic characteristics, complications, surgical completeness, and long-term outcomes using propensity score matching analysis. Results: Both groups had similar demographic characteristics including age, sex, tumor size, pathologic stage, and hospital stay after matching. Each group had similar rate of transient hypoparathyroidism, however, ET showed significantly higher rate of permanent hypoparathyroidism (ET 5.2% vs. RT 2.3%, P = 0.05), and transient vocal cord palsy (ET 14.4% vs. RT 9.1%, P = 0.006). Total operation time was longer in the ET group irrespective of surgical extents, including lobectomy (P = 0.016), total thyroidectomy (P = 0.031), and total thyroidectomy with central lymph node dissection (P = 0.019). The rate of patients with off-Tg under 1.0 ng/mL after 1st ablation was significantly higher in RT than ET group (ET 64.6% vs. RT 92.7%, P < 0.001). In long-term follow-up of cancer patients, 1.4% experienced recurrence after ET (10 cases), while 0.3% cases experienced recurrence after RT (5 cases) (P < 0.001). Conclusion: Both ET and RT can be safe and effective methods to treat thyroid diseases. However, the application of robotic system may help to overcome the limitations of the instruments and surgeon's skills.