Long-term outcome after mitral valve replacement with preservation of continuity between the mitral annulus and the papillary muscle in patients with mitral stenosis.

In 1964, Lillehei first described a reduction in mortality resulting from mitral valve replacement (MVR) with preservation of the posterior mitral leaflet in patients with low cardiac output syndrome. Because of this finding and the results of experimental studies (1), some surgeons began to perform MVR surgery that included the preservation of not only the posterior chordae tendineae and papillary muscles but also the anterior structures (2). Complete preservation of the mitral valve apparatus in MVR (preservation MVR, or PMVR) has frequently been observed to provide good early and long-term clinical results (3-10), primarily in studies of patients with mitral regurgitation (MR). On the other hand, the results of one study showed that the technique did not provide significant early improvements over results obtained with conventional MVR (CMVR) (11). It was reported in other studies that PMVR was effective in groups of patients with a variety of mitral valve disorders, including some with mitral valve stenosis (5,6,8), but few investigations have assessed the use of this technique only in patients with mitral stenosis. In the series of patients with a variety of disorders, complete PMVR was carried out using only autologous tissue; the procedure was difficult to perform in patients with severe mitral stenosis, who may have extensive fusion or hypertrophy (and sometimes also calcification) of the mitral valve apparatus. In other investigations, the preservation method was observed to be effective (12,13), but only the posterior portion of the mitral valve apparatus had been preserved. The present authors first performed PMVR (with preservation of both posterior and anterior structures) in patients with mitral stenosis about 18 years ago, using either autologous chordae tendineae or replacement of the chordae with expanded polytetrafluoroethylene (ePTFE) sutures. Here, the results of a study are reported comparing long-term follow up data from patients who underwent either PMVR or CMVR. Dr. T. Sugita, Department of Cardiovascular Surgery, Tenri Hospital, 200 Mishima, Tenri, Nara, 632-8552 Japan e-mail: taandsa@maple.ocn.ne.jp.