Mitral web--a new concept for mitral valve repair: improved engineering design and in-vitro studies.

BACKGROUND AND AIM OF THE STUDY A new mitral valve repair concept to treat mitral regurgitation (MR) due to valve prolapse was recently proposed. In this study, an improved design of this concept is presented, and the results of preliminary hemodynamic studies conducted in an in-vitro prolapse model are reported. METHODS The new repair approach is based on using a web/net attached to a standard annuloplasty ring spanning the annulus of the mitral valve. Experiments were conducted in a left ventricular simulator, using native porcine mitral valves. Severe MR was created by transecting the marginal chordae to induce P2 prolapse, and also by displacing the papillary muscles basally to induce bileaflet prolapse. RESULTS Implantation of the mitral web prevented leaflet prolapse and restored leaflet coaptation with trace mitral insufficiency, in both posterior and bileaflet prolapse. In posterior leaflet prolapse, implantation of the mitral web reduced the regurgitation volume from 10.43 +/- 3.76 ml to 2.13 +/- 1.83 ml per beat (p < 0.05). No visual damage was observed on the mitral valve leaflets after 4 h of continuous operation. CONCLUSION Based on the study results, the mitral web may represent a feasible option to repair different types of mitral valve prolapse. The mitral web may also significantly simplify mitral valve repair for complex lesions.