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

Gu et al.1Gu Z. Hao X. Liu Y. et al.Minimally invasive thymectomy could be attempted for locally advanced thymic malignancies: a real-world study with propensity-score matched analysis.J Thorac Oncol. 2023; 18: 640-649Abstract Full Text Full Text PDF Scopus (1) Google Scholar 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,2Fang W. Feng J. Ji C. Xiang Y. Minimally invasive thymectomy for locally advanced recurrent thymoma.J Vis Surg. 2016; 2: 58Crossref PubMed Google Scholar,3Xu N. Gu A. Ji C. Zhang X. Chen T. Fang W. Thoracoscopic thymectomy with partial superior vena cava resection for locally advanced thymomas.J Thorac Dis. 2019; 11: 438-444Crossref PubMed Scopus (5) Google Scholar 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 thymoma4Nakagawa K. Yokoi K. Nakajima J. et al.Is thymomectomy alone appropriate for stage I (T1N0M0) thymoma? Results of a propensity-score analysis.Ann Thorac Surg. 2016; 101: 520-526Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar,5Chao Y.K. Liu Y.H. Hsieh M.J. et al.Long-term outcomes after thoracoscopic resection of stage I and II thymoma: a propensity-matched study.Ann Surg Oncol. 2015; 22: 1371-1376Crossref PubMed Scopus (16) Google Scholar 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).6Shimizu H. Okada M. et al.Committee for Scientific Affairs, The Japanese Association for Thoracic SurgeryThoracic and cardiovascular surgeries in Japan during 2018 : Annual report by the Japanese Association for Thoracic Surgery.Gen Thorac Cardiovasc Surg. 2021; 69 (doi:10.1007/s11748-020-01460-w): 179-212Crossref PubMed Scopus (45) Google Scholar The 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 significantly higher in the second half of the study period. It is understandable that the degree of difficulty varies according to the different types of invasive tissue. Nevertheless, the scores assigned by the authors may not always be appropriate because, as mentioned previously, the combined resection for venous invasion requires considerable skill. Many other previous reports also exclude cases of vena cava invasion from the indication for thoracoscopic resection of invasive thymoma. The attempt to score the number of invaded organs is useful not only for surgical difficulty but also for predicting the prognosis of invasive thymoma. It has been reported that the postoperative prognosis of invasive thymoma correlates with the number of invaded organs.7Funaki S. Ose N. Kanou T. et al.Prognostic impact of number of organ invasions in patients with surgically resected thymoma.Ann Surg Oncol. 2022; 29: 4900-4907Crossref PubMed Scopus (2) Google Scholar Regardless, the authors have also completed surgery for this large-vessel invasion in some cases. The thoracoscopic partial resection of the brachiocephalic vein using a stapler has been previously reported,8Yano M. Okuda K. Kawano O. et al.Thoracoscopic thymectomy with tangential partial resection of the innominate vein.Ann Thorac Cardiovasc Surg. 2017; 23: 207-210Crossref PubMed Scopus (3) Google Scholar and it is likely that the authors have also performed partial resection using a stapler. Adequate preparation for intraoperative hemorrhage is essential to save the patient's life. I believe that further detailing what attention is paid to this aspect of the case series will provide the reader with pertinent information. Currently, there are no reports of superior vena cava reconstruction using artificial vessels performed through thoracoscopy or robotics. Although superior vena cava reconstruction through a median sternotomy is currently considered appropriate, there is a challenging case report in the field of cardiovascular surgery in which vascular reconstruction was performed by minimally invasive surgery.9Mirzai S. Yang B. Mitzman B. Torregrossa G. Balkhy H.H. Robotic repair of adult left-sided partial anomalous pulmonary venous connection.Ann Thorac Surg. 2021; 111: e77-e79Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar We look forward to the future development of minimally invasive surgery. Jun Nakajima: Conceptualization, Writing—Original draft preparation, Reviewing and editing. Minimally Invasive Thymectomy Could Be Attempted for Locally Advanced Thymic Malignancies: A Real-World Study With Propensity Score-Matched AnalysisJournal of Thoracic OncologyVol. 18Issue 5PreviewIncreasing evidence supports minimally invasive thymectomy (MIT) for early stage thymic malignancies than open median sternotomy thymectomy (MST). Nevertheless, whether MIT could be attempted for locally advanced disease remains unclear. Full-Text PDF