Principles of reconstructive surgery in degenerative mitral valve disease.

Degenerative mitral valve disease is the most common cause of mitral regurgitation (MR) in developed countries. The most common etiologies of valvular regurgitation are Barlow's disease and fibroelastic deficiency. The mechanism of MR is type II dysfunction (leaflet prolapse) due to chordae elongation or rupture in most patients. Associated annular dilation is a common lesion in almost all patients with chronic MR. By means of segmental valve analysis, isolated posterior leaflet prolapse (P2 segment) is often observed in patients with fibroelastic deficiency, whereas the prolapse of multiple segments or bileaflet prolapse is typically seen in patients with Barlow's disease. In patients with degenerative mitral valve disease and severe MR, reconstructive surgery should be performed before the occurrence of clinical symptoms, atrial fibrillation, pulmonary hypertension, and left ventricular dysfunction or enlargement. The goals of reconstructive surgery are preservation or restoration of normal leaflet motion, creation of a large surface of coaptation, and stabilization of the entire annulus with a remodeling annuloplasty. Today, reconstructive techniques are standardized, reliable, and reproducible, and therefore should be applied systematically to all patients with degenerative valvular disease.