Objective To compare the clinical efficacy of subxiphoid video-assisted thoracoscopic surgery (XVATS) and conventional intercostal VATS (CVATS) extended thymectomy for myasthenia gravis (MG). MethodsThe clinical data of MG patients who underwent extended thymectomy in the Department of Thoracic Surgery of Xuzhou Central Hospital from October 2016 to October 2021 and finished the follow-up were retrospectively reviewed. They were divided into an XVATS group and a CVATS group according to the procedure. The perioperative variables and clinical efficacy of the two groups were compared. ResultsA total of 84 patients were collected, including 43 males and 41 females, with a mean age of 52.3 years. There were 41 patients in the XVATS group and 43 patients in the CVATS group. There was no mortality, cardiopulmonary thrombosis, prolonged air leak, or mediastinal infection. Additionally, the CVATS group recorded 5 (11.6%) patients of conversion to open thoracotomy, 1 (2.3%) patient of postoperative MG crisis, 1 (2.3%) patient of bleeding in thorax, and 1 (2.3%) patient of chylothorax. The operation time (127.4±50.4 min vs. 122.9±38.6 min), intraoperative bleeding [46.9 (25.7, 79.2) mL vs. 45.7 (21.9, 92.1) mL], incidence of complications [0 vs. 7.0% (3/43)], chest tube duration (4.3±1.9 d vs. 4.8±2.8 d), follow-up time (19.1±8.5 months vs. 22.5±13.7 months), the proportion of residual mediastinal fat tissue [12.2% (5/41) vs. 4.7% (2/43)], and total MG remission rate [29.3% (12/41) vs. 51.2% (22/43)] were not statistically different between the two groups (P>0.05). However, the two groups showed significantly different incidence of conversion to open thoracotomy [0 vs. 11.6% (5/43), P=0.024], postoperative hospital stay time (8.2±3.3 d vs. 11.4±5.8 d, P=0.003) and total drainage volume [396.7 (173.8, 542.5) mL vs. 218.8 (102.1, 430.0) mL, P=0.038]. ConclusionXVATS extended thymectomy is technically safe and feasible; however, more evidence is warranted before the recommendation of this approach for the treatment of MG.