Background Minimally invasive thoracoscopic lobectomy is the recommended surgery for clinical stage I non‐small cell lung cancer (NSCLC). The purpose of this study was to identify the risk factors, including sarcopenia, for postoperative complications in patients undergoing a complete single‐lobe thoracoscopic lobectomy for clinical stage I NSCLC, as well as the impact of complications on disease‐free survival. Methods We retrospectively investigated 173 patients with pathologically‐diagnosed NSCLC who underwent curative thoracoscopic lobectomies between April 2013 and March 2018. Sarcopenia was assessed using the psoas muscle index calculated from preoperative computed tomography images at the third lumbar vertebral level. Results Complications developed in 38 (22%) patients, including 21 with prolonged air leak. In univariate analysis, the significant risk factors for complications were advanced age, male sex, higher Charlson Comorbidity Index (CCI) score, lower cholinesterase, lower albumin, higher creatinine level, pleural adhesion, operative time ≥ five hours, nonadenocarcinoma cancer, and larger tumor size. Multivariate analysis showed that age ≥ 75 years (P = 0.002) and pleural adhesion (P = 0.026) were significant independent risk factors for complications. Compared with the patient group without complications, postoperative complications were independently associated with shorter disease‐free survival (P = 0.01). Conclusions Advanced age and pleural adhesion were independent risk factors for complications after complete single‐lobe thoracoscopic lobectomies for clinical stage I NSCLC, and postoperative complications were statistically associated with poor prognosis. Surgical teams should ensure an experienced surgeon leads the operation for patients at higher risk to avoid prolonged postoperative hospitalization and a possible poor prognosis.

These results demonstrate the safety and substantially decreased invasiveness of TT for thymoma. The oncological results were comparable between the TT and OT groups. Furthermore, Masaoka stage III-IV and WHO B3-C were revealed as independent prognostic factors for DFS.

These results demonstrate the decreased invasiveness and feasibility of TT for large-sized thymomas.

As the generation advances, the model provides a more realistic simulation of thoracoscopic surgery. Further improvement of the model is needed.

type classification are valuable predictors of the prognosis of thymoma; hence, the optimal treatment for thymoma should be performed according to these two. TT is less invasive, with equivalent oncological outcomes, when compared with the OT. Minimally invasive surgery including TT for stage I-II thymomas is becoming the mainstay of therapy. (16,(20)(21)(22)(23). In our previous study (24), Masaoka stage III-IV thymoma patients experienced more recurrences than those with stage I-II patients. The 5-year disease-free survival (DFS) for stage III-IV thymomas was significantly poorer than those for stage I and II thymoma (47% vs. 97.5% and 94.1%, respectively). Hence, the Masaoka stage was a valuable predictor of the prognosis of thymoma. Keywords Pathologic classificationThe pathologic classification of thymoma has remained controversial for many years (25). The World Health Organization (WHO) has developed the most widely adopted pathologic classification for epithelial tumor of thymus by taking into consideration both histological and morphological features (26). There are two staging systems for epithelial tumor of thymus (27). Most widely used clinical stage was first described by Masaoka et al. in 1981, and it is a clinical staging system describing thymomas in terms of local extension or invasion of the tumor (6). The TNM staging follows the pattern of T for tumor descriptor, N for nodal spread, and M for distance metastasis. In 1999, the WHO Consensus Committee published a histologic typing system for neoplasms of the thymus (28). Thymomas are classified into types A, AB, B1, B2, B3, and C based on the morphology of epithelial cells and ratio of lymphocyteto-epithelial cells. Recently, the WHO Consensus Committee recommended that epithelial tumors of thymus be classified as thymoma, including type A, AB, B1, B2, and B3 thymoma and thymic carcinoma (29). Most of the WHO type A, AB, B1, and B2 thymomas are benign; however, types B3 and C have malignant potential (30). Our study (24) demonstrated that 16 of 140 thymomas patients experienced recurrences. Of those 16 patients, 12 patients had WHO type B3 or C thymomas. Thus, pathological aggressiveness seems to strongly influence recurrence. Several reports have indicated the impact of the WHO type on the decisionmaking during clinical treatments (26). Surgical treatmentMost patients having Masaoka stage I-II thymoma receive surgical treatment. Recently, TT has been attempted as a surgical treatment for thymoma. TT for thymoma consists of extended thymectomy (ET), total thymectomy, subtotal thymectomy (STT), and partial thymectomy according to the classification of the extent of the thymus resected. In this review, a few authors classified thymectomy by total and partial thymectomy, while some authors do not describe the resected extent of thymus clearly. Total thymectomy was defined as the resection of the entire thymus, and ET was defined as the resection with the thymus and surrounding fat tissues together. ET was usually performed in patients who had MG. F...