Complete Preservation of the Mitral Valve Apparatus during Mitral Valve Replacement for Rheumatic Mitral Regurgitation in Patients with an Enlarged Left Ventricular Chamber

Abstract

<p><b>Background and Aims:</b> The merits of retaining the subvalvular apparatus during mitral valve replacement (MVR) for chronic mitral regurgitation have been demonstrated in clinical investigations. This study was to investigate the feasibility of total preservation of the leaflet and subvalvular apparatus at the native anatomic position during MVR in a rheumatic population with enlarged left ventricular chamber.</p><p><b>Material and Methods:</b> The techniques of valvular apparatus preservation used during MVR with or without aortic valve replacement were investigated in 128 patients with an enlarged left ventricular chamber suffering from rheumatic mitral regurgitation between October 2003 and December 2007. Seventy patients had the anterior leaflet and subvalvular apparatus excised but the posterior leaflet and subvlvular apparatus preserved during the mitral valve replacement (P-MVR group), and 58 patients had the anterior and posterior mitral leaflets and the subvalvalur apparatus completely preserved at the native anatomical position during the mitral valve replacement (C-MVR group). Echocardiography was performed preoperatively, at discharge, and after 3 months, 1 year, and 3 years to determine the left ventricular dimensions and function.</p><p><b>Results:</b> There were 2 cases (3.4%) of early death in the C-MVR group, and there were 4 cases (5.7%) of early death in the P-MVR group. There were 3 cases of late death 1 year after surgery, of which 1 case in the C-MVR group was caused by congestive heart failure and the other 2 cases in the P-MVR group were due to sudden death. Both groups exhibited significant improvement (<i>P <</i> .05) in left ventricular function instantly and late postoperatively. The reduction of the left ventricular end-diastolic diameter was more significant in the C-MVR group as compared to the P-MVR group (<i>P <</i> .05). A statistically significant increase in fractional shortening (FS) occurred in the C-MVR group compared to the P-MVR group.</p><p><b>Conclusion:</b> This study shows that complete mitral leaflet preservation at the native anatomical position during MVR is feasible in rheumatic patients with an enlarged left ventricular chamber and confers significant short-term and long-term advantages by preserving left ventricular function and geometry. Therefore, it is a safe, simple, and effective surgical technique and should be individualized during clinical use.</p>