Minimally invasive cardiac surgeries in 2023–annual report of the Japanese association for minimally invasive cardiac surgery

Objective To establish updated nationwide perioperative benchmarks for minimally invasive cardiac surgery (MICS) in Japan by presenting the 2023 annual report and summarizing procedural trends from 2021 to 2023. Methods Data on mitral valve (MV) surgery, aortic valve replacement (AVR), coronary artery bypass grafting (CABG), atrial septal defect (ASD) closure, and cardiac tumor resection performed via MICS in 2023 were extracted from the Japan Cardiovascular Surgery Database. Perioperative outcomes, including 30-day mortality, in-hospital mortality, conversion to median sternotomy, and major morbidity, were evaluated. Three-year trends in case volume, institutional distribution, procedural complexity, and early outcomes were descriptively reviewed. Results The 2023 MICS cohort included the following cases: MV surgery (n = 3367), AVR (n = 1352), isolated CABG (n = 564), ASD closure (n = 232), and cardiac tumor resection (n = 126). Thirty-day and in-hospital mortality rates were 0.2% and 0.2%, respectively, in isolated MV repair, 1.3% and 1.9% in isolated MV replacement, 0.1% and 0.3% in isolated AVR, 0.9% and 1.2% in isolated CABG, 0% and 0% in ASD closure, and 0.8% and 1.6% in cardiac tumor resection. Among isolated procedures, the incidence of conversion to median sternotomy ranged from 0% to 2.6%. Over 2021–2023, case volume increased in all major categories, particularly in MV surgery and AVR, whereas MICS-CABG showed increasing complexity while maintaining acceptable early outcomes. Conclusions Nationwide MICS activity in Japan has expanded progressively over the past 3 years in both volume and procedural scope, while generally favorable early outcomes have been maintained. These updated results provide an important benchmark for ongoing quality assessment in contemporary MICS practice.