低侵襲僧帽弁形成術におけるセットアップ―体外循環中のピットフォールを中心に

Setup for Minimally Invasive Mitral Valve Repair：Pitfalls During Cardiopulmonary Bypass

低侵襲心臓手術（minimally invasive cardiac surgery：MICS）は，小切開による整容性の向上に加え，正中開胸手術と比較して出血量の減少，集中治療室（ICU）滞在期間の短縮，早期離床および早期社会復帰などの利点を有する術式として発展してきた．近年は内視鏡機器や人工心肺（CPB）の進歩により安全性が向上し，本邦でも標準的治療として普及している．さらに，術前評価から人工心肺確立時のカニュレーション部位の選択，体外循環管理，合併症対策まで標準化がすすみ，安全性および再現性の向上が期待されている1）．MICS僧帽弁手術についても標準化がすすみ，低侵襲性のみならず安全性や長期成績において従来手術と同等以上の成績が報告されている2）．

Minimally invasive mitral valve plasty （MICS-MVP） through a right mini-thoracotomy offers several advantages over conventional median sternotomy, including reduced surgical trauma and faster postoperative recovery. However, achieving repair quality equivalent to that of open surgery requires meticulous operative planning, secure exposure, and optimized cardiopulmonary bypass （CPB） management. At our institution, 96％ of isolated mitral valve repairs performed between 2018 and 2025 were completed using a MICS approach. Based on this experience, we describe the surgical outcomes and key technical considerations specific to right mini-thoracotomy MVP. This review focuses particularly on preoperative imaging findings essential for patient selection and procedural planning, as well as practical strategies for establishing peripheral CPB. We discuss common pitfalls and troubleshooting techniques associated with femoral cannulation and lower-extremity perfusion, including representative clinical cases illustrating intraoperative complications and their prevention. In addition, we outline important aspects of intraoperative management unique to MICS, emphasizing methods to maintain procedural safety and stable operative fields while preserving repair quality. Furthermore, we describe the learning process for acquiring MICS-specific skills and summarize our institutional pathway toward certification in minimally invasive cardiac surgery. By sharing these experiences, we aim to provide practical guidance for standardizing MICS-MVP techniques without compromising safety. Ultimately, dissemination of these technical insights may help reduce inter-institutional and inter-operator variability and contribute to the broader adoption of safe and high-quality minimally invasive mitral valve repair.