经导管二尖瓣置换术的应用现状与展望

Current status and future prospect of transcatheter mitral valve replacement

经导管二尖瓣置换术(transcatheter mitral valve replacement,TMVR)是指将人工瓣膜在体外压缩、装载至输送系统,然后沿着血管路径或经心尖途径送达二尖瓣瓣环处以替代病变瓣膜的一种介入手术,目前仅限于在有外科手术禁忌的二尖瓣反流患者中作探索性研究。TMVR包括瓣中瓣、环中瓣、自体环中瓣和自体瓣中瓣手术。在前3种手术中,人工瓣环或钙化的自体瓣环能起到径向支撑作用,使用现经导管主动脉瓣置换术所用人工瓣膜即可完成TMVR,且技术也较成熟。用于自体瓣环无明显钙化的二尖瓣反流患者(占二尖瓣病变患者的绝大多数)的自体瓣中瓣手术是真正意义上的TMVR。不过,目前大多数TMVR所用人工瓣膜的功能还不令人满意,只有Tendyne瓣膜的临床效果较为令人乐观。预期在不久的将来,TMVR可能成为对外科手术有禁忌或高危的二尖瓣反流患者的有效治疗手段。但距TMVR广泛用于临床,特别是用于外科手术风险相对较低的二尖瓣反流患者,还面临诸多挑战。

Transcatheter mitral valve replacement （TMVR） is an interventional surgery compressing the artificial valve in vitro, loading it on delivery system and delivering it to mitral annulus through the vessel or apex to replace valve in situ and is currently only limited to surgical contraindications for exploratory research in patients with mitral regurgitation. TMVR includes four techniques such as valve in valve, valve in ring, valve in native ring, and valve in native valve. In the first three techniques that are relatively mature, the artificial valve ring or calcification of the valve ring can provide a radial force support and therefore a TMVR procedure can be completed using the current TAVR valve. Autologous mitral valve regurgitation for patients with mitral valve regurgitation but without obvious calcification is a true sense of TMVR （the vast majority of mitral valve regurgitation patients suffer from autologous mitral valve regurgitation）. The performance of most of the TMVR valve is not satisfactory at present, however the clinical results of Tendyne valve are relatively optimistic. It is expected that TMVR may be an effective treatment for patients with mitral regurgitation who are contraindicated or at high risk for surgery in the near future and however, there are many challenges to be faced before its wide application in clinical practice, especially in patients with mitral regurgitation and relatively low risk of surgical intervention.