僧帽弁閉鎖不全症に対する経心尖部アプローチによる人工腱索再建デバイスの提案

New Device for Mitral Valve Repair

現在，僧帽弁閉鎖不全症に対する術式は，可能であれば人工弁置換術よりは弁形成術が選択される傾向にある．弁形成術は一般に抗凝固療法が不要であり，左室機能の温存に優れているとされている1）．通常，僧帽弁形成術は人工心肺を用い，直視下に矩形切除や人工腱索再建，弁輪縫縮などの修復法が行われている．

Purpose：Our objective is to develop a new device for the treatment of mitral regurgitation by transapical chordal implantation, allowing procedures to be conducted while the heart is beating, thus eliminating the need for extracorporeal circulation. This approach promises both simpler and more reliable procedure than existing devices.

Methods：The target disease is mitral valve prolapse, where adequate coaptation of the anterior and posterior leaflets can be achieved solely through chordal implantation. Our treatment approach involves accessing the mitral valve via the left ventricular apex, attaching an artificial chorda tendineae to the prolapsed mitral valve leaflet, and pulling it to an appropriate length towards the left ventricular apex. We propose the design and operational mechanism of a device to facilitate this procedure.

Results：The device utilizes a grasper with a hollow structure to catch the prolapsed valve leaflet and then attaches the artificial chordae tendineae to the valve leaflet by using a clip within the hollow structure. This structure enables visual confirmation of the procedure using a fiber scope, thus ensuring greater procedural reliability.

Conclusion：This device represents a conceptual breakthrough, although several considerations remain, such as the durability of the materials used and their compatibility with tissue.