Robotic thymectomy for large thymomas: a multicenter study

: This study aimed to evaluate surgical and oncological outcomes of robot-assisted (RATS) thymectomy in the treatment of large (diameter >  = 5 cm) resectable thymomas. Clinical data of 301 thymectomies for thymoma, performed in 7 high-volume centers from 2010 to 2023, were retrospectively reviewed. 132 RATS thymectomies were performed: 59 (44.7%) for small and 73 (55.3%) for large thymomas. Conversion (p = 0.48), significant complications (p = 0.26), and hospital stay (p = 0.79) were similar in both groups. Overall, 191 large thymomas were operated on: 73(38.2%) by RATS, 118 (61.8%) by open approach. Comparing the RATS approach with the open standard approach for the treatment of large thymomas, more post-operative complications (p < 0.001) but similar major complications (p = 0.11) and a longer in-hospital stay (p < 0.001) were recorded in the open group. Five-year OS (95% vs 85%, p = 0.14) and DFS (86 vs 93%, p = 0.18) of patients affected by large thymomas were comparable between RATS and the open group. To minimize selection-confounding factors between the two large thymoma groups (RATS vs open) in relation to the outcomes, a 1:1 propensity score match (PSM) analysis was performed, and surgical and oncological outcomes reassessed. Chest tube length (p < 0.001) and in-hospital stay (p < 0.001) were confirmed to be longer in the open group. Prognostic factors for oncological outcomes for large thymomas were also confirmed after PSM analysis. Adjuvant radiotherapy was the only predictive factor (p = 0.033) affecting DFS, while no factor was confirmed for OS at multivariable analysis. RATS seems to be a safe and effective alternative to open surgery for treating large thymomas.