Objective To evaluate the feasibility of video-assisted thoracoscopic surgery in the treatment of thymoma with≥50 mm in diameter.

Methods We retrospectively analyzed the clinical and pathological data of 121 cases of Masaoka Ⅰ-Ⅲ thymoma treated with VATS and open thymectomy from January 2012 to December 2017, and compared the effect of two surgical methods on thymoma with ≥50 mm in diameter during perioperative period.

Results Among the 121 thymoma patients, those with large tumor diameter had more intraoperative blood loss, more cases converted to open surgery, the drainage tube retention time was longer, postoperative drainage was more, and there was statistically significant difference between large tumor group and small tumor group(P < 0.05). Among early-stage patients with large tumor diameter, 26 patients who underwent thoracoscopic surgery had less intraoperative blood loss, lower postoperative complication rate, shorter drainage tube retention time, less postoperative drainage and shorter hospital stay than those who underwent thoracotomy (P < 0.05). Among the early-stage patients who underwent thoracoscopic surgery, there were no statistically significant difference between the large and small tumor groups (P > 0.05). Among the Masaoka Ⅲ patients, the VATS group had longer operation time, more intraoperative blood loss, higher postoperative complication rate and more postoperative drainage, and there was statistically significant difference between VATS group and open surgery group (P < 0.05).

Conclusion Thoracoscopic surgery for Masaoka Ⅰ-Ⅱ tumor with ≥50 mm in diameter could be more minimally invasive, more quickly postoperative recovery and better clinical feasibility. But for Masaoka Ⅲ patients, thoracoscopic surgery is difficult for operator and the curative effect in perioperative period is poor.