Long-term outcome of minimally invasive thymectomy versus open thymectomy for locally advanced cases.

Objectives: Our goal was to compare the oncological outcomes and efficacy between minimally invasive thymectomy (MIT) and open thymectomy (OT) in patients with early or locally advanced thymoma using a multicentre study database.

Methods: We retrospectively collected data from 1,239 patients who underwent thymectomy between January 2000 and December 2013, as recorded in the database of the Korean Association for Research on Thymus. We compared the postoperative outcomes of the MIT and OT groups using unmatched and propensity score (PS) matched data.

Results: We excised the thymoma using MIT and OT in 455 and 784 patients, respectively. We matched 378 patients with Masaoka-Koga stage I or II thymoma by their PS. The operative time, duration of hospital stay and complications were significantly shorter in the MIT group than in the OT group (all P < 0.005). In the PS matched data, the groups did not show significant differences in the 10-year survival rate (87.7% in OT vs 85.5% in MIT, stage II, mean follow-up duration: 12.9 years in OT vs 11.1 years in MIT), recurrence-free survival (94.0% in OT vs 86.4% in MIT) and R0 resection (97.35% in OT and MIT, P = 0.59).

Conclusions: Compared with OT, MIT was associated with shorter operative times, shorter durations of hospital stay and fewer complications. Long-term survival, recurrence-free survival and complete resection were not significantly different between the OT and MIT groups. Our findings may help physicians track the progress of patients with early or locally advanced thymomas and design treatment plans for them.