Mastering Mitral Leaflets Coaptation After Valve Repair with Adjustable Mitral Annuloplasty Ring: Proof of Concept in Mock Loop Study.

Abstract

This investigation sought to determine the feasibility of a novel mitral ring designed to reshape mitral annulus on beating heart, after surgery. The mitral ring is intended to improve mitral leaflets coaptation to correct residual and recurrent mitral regurgitations. It could also provide progressive correction of mitral regurgitation. The device was tested in ex vivo beating heart model. The novel mitral ring is selectively deformable in P1, P2, and P3 segments using a dedicated angioplasty-type balloon. The deformation should increase leaflets coaptation, reducing distance between the two leaflets. It was implanted using standard surgical techniques. The mock loop is based on passive beating heart. Mitral valve (MV) functioning was evaluated in terms of leaflets coaptation height at P2 level using epicardial echocardiography. The test has been completed on eight swine hearts. Ring size was 30 mm. The balloons were inserted in the connecting line. Each segment of the posterior annulus was independently activated over three progressive positions. Balloon inflation pressures were between 15 and 21 bar. Maximum coaptation height increase was 7 mm. Mean pressure gradient across the MV was 1.7 ± 0.3 mm Hg after complete activation of the device. The device allowed significant increase in coaptation height at P2 level after adjustments at P1, P2, and P3. Results were consistent and reproducible. This feasibility study demonstrates the possibility to reshape the mitral annulus on beating heart to precisely increase MV leaflets coaptation height.