Percutaneous reduction of septal-to-lateral mitral annular distance to increase mitral leaflet coaptation length: Preclinical study results

OBJECTIVES: Percutaneous indirect annuloplasty has emerged as a treatment strategy for functional/ischemic mitral regurgitation. This study sought to evaluate the feasibility of percutaneous indirect annuloplasty technique using a new device. METHODS: The device has 3 components: the “saddle” inserted into the great cardiac vein, the “plug” positioned in the left ventricular outflow tract, and the “bridge,” a transatrial suture connecting the 2 holding elements. The aim was to shorten the septal-to-lateral distance of the mitral annulus by pulling on the saddle element. The procedure was performed through venous access in healthy adult sheep. A dedicated catheter holding a needle was used to deploy the saddle into the great cardiac vein and pierce its wall toward the left atrium to deploy the expanded polytetrafluoroethylene suture that is part of the bridge. A catheter for transseptal puncture was inserted for crossing the interatrial septum and piercing the aortic-mitral curtain, thereby allowing the plug to be deployed. The plug was held in place by the second part of the expanded polytetrafluoroethylene bridge. The 2 parts of the bridge were then joined to reduce the septal-to-lateral mitral annular distance. The septal-to-lateral distance and the coaptation length at P2 level were measured before and after the procedure using echocardiography. RESULTS: Overall, 10 animals were treated, 7 successfully. The mean procedure duration was 110 ± 81 minutes. Septal-to-lateral distance decreased from 3.8 mm to 2.6 mm (30%), and maximum increase of mitral leaflet coaptation was 4 mm. CONCLUSIONS: This new approach seems promising for percutaneous treatment of functional mitral regurgitation.