Minimally Invasive Thymectomy Could Be Attempted for Locally Advanced Thymic Malignancies: A Real-World Study With Propensity Score-Matched Analysis

performed a retrospective analysis on outcomes of minimally invasive thymectomy (thoracoscopy) for locally advanced thymic epithelial neoplasms in their institution.The authors have already reported on thoracoscopic resection of invasive thymic neoplasms, 2,3 and they compared the series with open chest surgery in this article.Their efforts to expand the indications for minimally invasive surgery should be commended.Thymomectomy with total thymectomy through a median sternotomy was once considered the standard procedure for thymic epithelial neoplasms.Besides the problem of thoracoscopic or robotic surgery, this was due to concerns about multiple thymomas and the development of postoperative myasthenia gravis.Nevertheless, recent studies have found that total thymectomy for thymoma is not always necessary, with papers revealing no significant difference in prognosis between total thymectomy and partial thymectomy in T1 thymoma 4,5 and postoperative myasthenia gravis is not necessarily caused by incomplete resection.This is likely due to the fact that thoracoscopic surgery for thymic tumors is gradually becoming more widespread.According to the database of the Japanese Association for Thoracic Surgeons, the percentage of thoracoscopic procedures for thymoma is gradually increasing and approximately two-thirds of thymoma surgeries were performed through thoracoscopy (Fig. 1). 6The same trend is likely to be true around the world.Furthermore, thoracoscopic surgery for invasive thymoma is increasingly being challenged.Practically, partial pericardial (T2) and pulmonary (T3) resections, which are less risky, are not so difficult; however, the surgical difficulty is very high when there is brachiocephalic and vena cava venous invasion, which is also categorized as T3.The authors scored the difficulty according to the type of invasive tissue adjacent to the tumor, and they found that the difficulty of the procedure was