Safety and Learning Curve of Totally Endoscopic Mitral Valve Plasty: Initial 125 Cases Evaluated by Operative Time and RA-CUSUM Method

Objective: Totally endoscopic mitral valve plasty (TEMVP) requires technical proficiency, which may be insufficient during the initial adoption phase. This study evaluated the learning curve and perioperative outcomes during the early experience with TEMVP, using operation time and complications as key metrics. Methods: We retrospectively analyzed 125 consecutive patients who underwent TEMVP between October 2021 and April 2025. Despite the early adoption phase, 40 patients met criteria for complex pathology (i.e., concomitant procedures, infective endocarditis, reoperation, narrow thoracic cage, or difficult aortic cross-clamping) and were defined as the complex group. The remaining 85 patients formed the control group. Surgical outcomes were compared between groups. The learning curve was assessed using operation time and risk-adjusted cumulative sum (RA-CUSUM) analysis based on predicted morbidity (Japan Score). Results: The complex group had longer operative times (335 ± 71 vs 282 ± 61 min, P < 0.001) and higher complication rates (17.5% vs 3.5%, P = 0.012). Two-year survival was 94.7% in the complex group and 100% in the control group ( P = 0.03); freedom from reoperation was 100% and 94.2%, respectively ( P = 0.30). Operation time significantly decreased over time in the overall and control groups but not in the complex group. RA-CUSUM analysis showed favorable cumulative trends below the predicted risk threshold, with no group exceeding the sequential probability ratio test decision limit of ±3.74. Conclusions: Despite the inclusion of complex cases, early TEMVP outcomes were favorable and within acceptable safety limits. RA-CUSUM and operation time analysis supported the presence of a manageable learning curve at our institution.