低侵襲僧帽弁形成術の遠隔期成績と治療ストラテジー

Long-term Outcomes and Treatment Strategies for Minimally Invasive Mitral Valve Repair

僧帽弁閉鎖不全症に対する低侵襲僧帽弁形成術（minimally invasive mitral valve plasty：MICS-MVP）は，患者侵襲の軽減，術後回復の早期化，整容性向上を目的として近年急速に普及している．一方で，限られた術野での繊細な操作を要するため，術者の習熟や安定した形成手技が必要とされる．当院では早期より，変性性僧帽弁閉鎖不全症（degenerative mitral regurgitation：DMR）例に対し，MICS-MVPを積極的に導入してきた．さらに，人工腱索を主体とした形成手技やpartial bandを用いた弁輪形成を標準化することで，術式の再現性向上と遠隔期成績改善をめざしてきた．本研究では，当院におけるMICS-MVPの治療戦略および遠隔期成績について検討した．

We have actively adopted minimally invasive mitral valve plasty （MICS-MVP） since the early phase of its introduction. Between October 2012 and March 2021, we performed MICS-MVP in 264 patients with degenerative mitral regurgitation. The mean age was 58.5 （range, 18～82） years；104 patients （39％） were female, and 60 patients had concomitant atrial fibrillation. Concomitant procedures were performed in 150 patients, including tricuspid valve surgery in 56 patients, arrhythmia surgery in 59, left atrial appendage procedures in 58, and congenital heart disease surgery in 39. The mean operative time was 254 minutes. Regarding repair techniques, artificial chordae were used in 139 cases；annuloplasty was performed using a full ring in 101 cases and a partial band in 162 cases. The 5-year survival rate was 98.1％, and the 5-year freedom from major adverse cardiac and cerebrovascular events （MACCE） was 92.8％. There were no cardiac deaths, and 7 readmissions for heart failure. Compared with the full-ring group, the partial-band group showed a significantly lower mean mitral valve pressure gradient （p＜0.001）. By multivariable analysis for MACCE incidence and readmission for heart failure, none of the factors―including surgical technique and choice of annuloplasty device―were detected as significant predictors. In recent years, annuloplasty with partial band and artificial chordae has become our standard procedure to prevent functional mitral stenosis. Further standardization of surgical techniques may contribute to improve long-term outcomes.