MITRAL-VALVE REPLACEMENT WITH GLUTARALDEHYDE PRESERVED AORTIC ALLOGRAFTS

Objective: To present long-term results after mitral valve replacement with stent mounted glutaraldehyde preserved aortic allografts in pati ents older than 15 years. The clinical support for this study was to c ombine the glutaraldehyde technique of biological tissue preservation with the advantages of allografts when compared to xenografts. This wa s demonstrated in previous studies using other methods of tissue proce ssing. Methods: Between September 1984 and November 1994, 70 patients aged 16-77 years (mean 35.4 years) underwent mitral valve replacement with this preserved and mounted allograft. Of these, 40 patients (57.2 %) were aged 16-35 years and 15 (21.4%) were 20 years old or younger; 46 (65.7%) were females and 24 (34.3%) males. Single mitral valve repl acement was performed in 60 patients and 10 were also subjected to oth er combined cardiac procedures. Human aortic valves were obtained duri ng routine autopsy, processed in glutaraldehyde and mounted into flexi ble stents, using the same technique as that used for porcine bioprost heses. Results: Hospital mortality was 1.4%. Total follow-up was 543.1 patient-years, corresponding to a mean follow-up of 7.9 years per pat ient. Echocardiography demonstrated a hemodynamic performance similar to porcine bioprostheses. Late mortality was 0.7 +/- 0.6% per patient- year and the causes were congestive heart failure in 2, prosthetic end ocarditis in 1 and acute myocardial infarction in 1. The 12-year actua rial survival was 92.4 +/- 3.2%. The incidence of late complications w as 5.2 +/- 1.2% per patient-year, including congestive heart failure, prosthetic endocarditis, periprosthetic leak, thromboembolic episodes, recurrence of rheumatic disease, coronary artery disease and allograf t failure. Complications related to heart disease represented 2.8 +/- 0.6% and allobioprosthesis-related 2.4 +/- 0.5% per patient-year. The 12-year actuarial freedom from primary valve failure was 81.0 +/- 15.0 %. The incidence of reoperations was 1.5 +/- 0.8% per patient-year and the main indication was prosthetic endocarditis. Other causes were pe riprosthetic leak, aortic insufficiency in the native aortic valve and allobioprosthesis dysfunction. Functional results demonstrated a sign ificant improvement in patients clinical condition. Conclusion: This 1 2-year follow-up shows a very low incidence of primary allograft failu re for patients older than 15 years undergoing mitral valve replacemen t, and much superior than our results with porcine bioprosthesis in th e same age group. This supports our assumption that this investigation al valve represents a new advance in cardiac valve surgery. (C) 1998 E lsevier Science B.V. All rights reserved.