LONG-TERM RESULTS OF MITRAL-VALVE REPLACEMENT WITH PRESERVATION OF THE POSTERIOR LEAFLET

Background and aims of the study: It is commonly held that preservatio n of the annulo-ventricular continuity during mitral valve replacement has a beneficial effect on postoperative ventricular function. This p aper presents our eight-year experience with this technique. Materials and methods: From 1986 to December 1992, 120 patients with rheumatic valve disease underwent mitral valve replacement (MVR) combined with p reservation of the posterior leaflet of the mitral valve. The mean age was 33.87 years (range 16 to 63). The preoperative New York Heart Ass ociation (NYHA) class was III in 64 % of the patients and IV in 3%. Th e early (30 day) mortality rate was 2.5% (3/120). Follow up was 100% c omplete. The total cumulative follow up was 477 patient-years (pty) wi th a mean 3.94 years (range: 2-8 years). Results: The actuarial surviv al rate (including hospital mortality) was 87.6% at eight years. Advan ced age (p = 0.0457), increased preoperative functional capacity (p = 0.0251), increased preoperative end-systolic diameter (p = 0.0352) and combined tricuspid reconstruction (p = 0.0001) were found to be indep endent parameters for a lower actuarial survival rate. Six patients (1 .25%/pty) developed thromboembolic complications. Two of these were ce rebrovascular accidents (0.41/pty) and four were caused by mechanical valve thrombosis (1.83%/pty). Freedom from thromboembolic complication s (including mechanical valve thrombosis) was 89.8% +/- 7.9%. Fifteen patients (3.14%/pty) developed valve failure, four (0.83%/pty) mechani cal valve thrombosis and nine (1.88%/pty) bioprosthetic valve failure. Freedom from reoperation was 60,7% +/- 16.1%. One patient with a St. Jude Medical valve (0.2%/pty) suffered from prosthetic valve endocardi tis. Three patients (0.62%/pty) died during the follow up period, and freedom from all valve related complications was 51.4% +/- 16.1% at ei ght years. Conclusion: Preservation of the posterior leaflet during mi tral valve replacement reduces the risk of early mortality and did not cause additional complications to the patients. Despite the beneficia l effects of this technique in the long term, this technique did not i ncrease the long term survival in patients with associated impaired va lvular and/or ventricular function.