經導管MitraClip治療二尖瓣閉鎖不全

Transcatheter MitraClip Therapy for Mitral Regurgitation

二尖瓣的閉鎖不全（mitral regurgitation, MR）是最常見的瓣膜疾病之一，它也是心衰竭非常見的病因或合併症。二尖瓣閉鎖不全大分為兩類：一類是原發性（primary），也就是瓣葉本身（leaflets）、腱索（chordae tendineae）、或乳突肌（pupillary muscles）不正常造成的二尖瓣閉鎖不全；另一類更常見的則是所謂的續發 性（secondary）或者功能性（functional）的二尖瓣閉鎖不全，其二尖瓣瓣葉解剖正常，閉鎖不全的成因主要是左心室心肌病變所導致。對於嚴重二尖瓣的閉鎖不全，藥物治療是無法根治的，要徹底治療過去只有外科手術開心手術做二尖瓣修復（repair），或者是置換新的人工瓣膜（replacement）—途。近年來二尖瓣的閉鎖不全進入經導管治療（transcatheter interventions）的時代。經導管處理二尖瓣閉鎖不全技術的設計理念也都是基於外科的觀念，主要有經導管二尖瓣置換術（transcatheter mitral valve replacement）及經導管二尖瓣修復術（transcatheter mitral valve repair）兩大類術式。其中最普遍使用的是經導管MitraClip夾合器技術，將前後兩個瓣葉邊緣對接（edge-to-edge repair）來治療二尖瓣閉鎖不全，這也是唯一同時通過歐洲CE及美國FDA認證的技術。本文旨在介紹當前經導管治療二尖瓣閉鎖不全的現況，並聚焦於經導管MitraClip夾合器技術的使用及未來展望。 Mitral regurgitation (MR) is a leading cause of valvular heart disease worldwide and is also commonly seen in patients with heart failure. MR is classified as primary regurgitation from intrinsic valvular disease or secondary regurgitation resulting from left ventricular dysfunction. Severe symptomatic regurgitation of both types carries a poor prognosis. Surgical valve repair or replacement is the current recommended therapy for severe symptomatic primary MR and asymptomatic MR when associated with left ventricular dysfunction, atrial fibrillation, or pulmonary hypertension. Open-heart surgery is the gold standard for the treatment of severe MR as excellent outcomes can be achieved in most patients, often adopting minimally invasive approaches. However, in many patients with severe MR surgical treatment is not performed owing to increased risk related to comorbidities. Thus, there is a clear need for a less-invasive intervention in this high-risk population. Transcatheter mitral interventions including repair and replacement technologies are being developed to expand the transcatheter intervention armamentarium and may be an alternative therapeutic option. Among them, transcatheter edge-to-edge repair with the MitraClip system (Abbott Vascular Inc, Menlo Park, CA, USA) has demonstrated safety and efficacy in different clinical settings and has been an alternative to surgery since 2013. However, many questions must still be answered about the most appropriate patient population to treat and when to treat them. With time and further research, these questions can be answered, and the future of the MitraClip will be determined.