6. 大動脈弁置換術後僧帽弁手術

Mitral Valve Surgery after Previous Aortic Valve Replacement

僧帽弁に対するカテーテル治療デバイス（MitraClip：アボットメディカルジャパン社，東京）は2018年4月から本邦でも使用可能であるが，その適応は限定的であり，主に外科的手術の危険性が高い症例や不可能な症例にのみ使用されている．特に大動脈弁置換術後のMitraClipの成績は良好とはいえず1），現時点では大動脈弁置換術後の僧帽弁手術は体得すべき手術の一つである．再手術に伴うポイントについて述べたい．

Transcatheter mitral valve intervention, including repair and replacement, has been developed as an alternative treatment to mitral valve surgery with advanced technology in recent years, but the therapeutic indication is still limited to only a part of all, high-risk or inoperable patients. Although reoperative valve surgery is generally known to be associated with increased morbidity and mortality, conventional mitral valve surgery after previous aortic valve replacement is needed due to limited usage of catheter intervention as increasing of aged population. It is usually necessary to undergo redo median sternotomy with care as same as other reoperation, or right thoracotomy approach in some cases. In any cases, there is a tendency to poor visualization of the mitral valve, in especially, a view of anterior annulus due to rigid aortic prosthetic cuff. Of course, optimal visualization of the mitral valve is a successful key factor in reliable maneuver for either repair or replacement. Here we describe operative tips and pitfalls including operative indication, re-opening of the chest, left atrial approach.