Endovascular Edge-to-Edge Mitral Valve Repair: Short-Term Results in a Porcine Model

Background—The edge-to-edge technique is an accepted method for the surgical repair of a regurgitant mitral valve. This study reports the initial use of an endovascular technology that enables a double-orifice edge-to-edge mitral valve repair without cardiopulmonary bypass in an animal model. Methods and Results—Adult pigs (n=14) were anesthetized, and left thoracotomy was performed for epicardial echo imaging. Using femoral vein access, a steerable guide catheter was placed transseptally into the left atrium. An implantable clip designed to grasp and approximate the middle scallops of the anterior and posterior mitral leaflets was introduced through the guide catheter. The clip was opened in the left atrium, advanced through the mitral orifice, and retracted to grasp the leaflet edges. When a functional double-orifice valve was confirmed by echo, the clip was closed to coapt the leaflets and detached from the delivery catheter. Before final clip detachment, echo demonstrated a double orifice in all 14 animals. In 2 studies, the clip released from the anterior mitral leaflet. Retrospective analysis of echo images indicated an incomplete grasp of the anterior leaflet. Immediate postmortem examination revealed that the clip successfully approximated the middle scallops of the anterior and posterior leaflets in all 12 double-orifice studies. Conclusions—This study demonstrates for the first time that an endovascular system can be successfully used to perform the edge-to-edge repair technique in a nondiseased porcine model. This technique is potentially applicable as a percutaneous catheterization laboratory procedure for the treatment of mitral regurgitation in humans.