単結紮ロック手技による僧帽弁人工腱索長の調整

A Single-knot Lock Procedure for Adjustment of Artificial Chordae in Mitral Valve Repair

僧帽弁形成術での人工腱索長の決定は，弁の接合や予後にかかわる重要な問題である．さまざまな方法が提案されているものの，的確な腱索長の決定はむずかしく，技術的にも挑戦的な手技の一面をもつ1，2）．われわれは，糸結びの単結紮での縫合糸のロックを利用した，簡易な人工腱索長の調整法を考案したので報告する．

We describe a simple and reproducible technique for adjustment of neochordal length in mitral valve repair with a single-knot lock procedure. A small loop with polytetra fluoroethylene （CV-4）is secured on the papillary muscle as an anchor for the neochordae. A needle with CV-5 suture is passed through the anchor loop, and both ends of the suture are passed through the free edge of the prolapsed mitral leaflet. A single knot is made on the leaflet with the 2 ends of each suture thread, and the ends of each pair of suture threads are secured with small hemostatic clamps. The hemostatic clamps are suspended over the edge of the wound to apply traction to the single knot. The knot is locked with this tension and the friction between the threads. The saline injection test is applied, and the height of the artificial chordae is adjusted by sliding the knot to the appropriate position. After valve competency is obtained, the knot is held by curved hemostatic forceps, and the threads of the suture are tied on the leaflet. This technique for adjustment of neochordal length is quick, reliable, reproducible, and increases the technical possibilities for mitral valve repair.