Background The current staging systems do not consider the tumor location of thymomas, and its clinical relevance is poorly understood. This study aimed to evaluate the impact of tumor location on the clinicopathological features and prognosis of thymomas. Methods We performed a retrospective review of patients at our institution who underwent an extended thymectomy for a thymoma from 1976 to 2015. The tumor location was classified as either the superior or inferior mediastinum based on the maximum tumor diameter. The clinicopathological characteristics of the thymoma were also evaluated. Kaplan‐Meier estimates and Cox proportional hazards models were used to analyze the survival outcomes and risk factors for recurrence. Results A total of 194 patients with thymoma were eligible for this study. Compared with the inferior mediastinum group (n = 167), the superior mediastinum group (n = 27) had a higher frequency of myasthenia gravis (MG), advanced Masaoka‐Koga staging, disease progression and recurrence (P < 0.05). The Kaplan‐Meier analysis demonstrated thymomas in the superior mediastinum had worse survival outcomes that included overall survival, progression‐free survival and disease‐free survival (P < 0.05). The multivariate analysis showed tumor location was an independent prognostic factor for all the survival outcomes (P < 0.05). Furthermore, the tumor location (P = 0.004) and Masaoka‐Koga stage (P < 0.001) were the only two independent risk factors for recurrence in the multivariate analysis. Conclusions The clinicopathological features of thymomas on MG, Masaoka‐Koga staging, disease progression, and recurrence were different between locations of superior and inferior mediastinum locations. Thymomas in the superior mediastinum tended to be associated with worse survival and increased recurrence.

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Background: Although the cuff technique in rat lung transplantation (LTx) has a long history, it remains technically challenging. We have developed key tricks and modifications in the devices and the cuff technique that optimize the rat LTx model to achieve successful operations during a short learning period. Methods: Altogether, 180 consecutive rats underwent orthotopic left LTx performed by a single surgeon using our modified devices and procedures. Allogeneic and syngeneic transplantation were performed using Lewis rats as recipients and Brown Norway and Lewis rats as donors. Allogeneic recipients were treated with cyclosporine during the first week. Recipients were sacrificed at various time points after ≥2 weeks. Results: A special cuff-preparation plate was created using a petri dish and two foam blocks. This modified plate stabilizes the preparation and prevents donor lung compression. A "┴"-shaped incision was carved into the front wall of the pulmonary artery (PA) using micro-scissors. "V"-shaped incisions were made from the inferior-to-superior branches of the pulmonary vein (PV) and bronchus. A "pendulum model" was applied at implantation to make the hilar anastomosis tension-free and technically easier to perform. There were no intraoperative complications. Ten rats (5.6%) experienced partial or full pulmonary atelectasis. Five deaths (2.8%) due to pleural effusion occurred during the follow-up period. The operative times for heartlung block retrieval, cuff preparation, cold ischemia, warm ischemia, and total procedure time were 8. 4±0.8, 11.6±1.5, 25.1±2.2, 8.1±1.2, and 46.7±2.8 min, respectively. Conclusions: The key tricks and improvements we made in the cuff technique for rat LTx provided the advantages of expeditiousness, a low complication rate, and a high success rate.