Performance of glutaraldehyde-preserved porcine bioprosthesis as a mitral valve substitute in a young population group.

Porcine bioprostheses were implanted in the mitral position in 289 patients. The mean age was 25.8 +/- 13.7 years. One hundred thirty-five patients (47%) were 20 years old or younger. Most patients had chronic rheumatic valvulitis (74%). Mitral regurgitation and mixed mitral valve disease were the dominant lesions. Hancock, Angell-Shiley, and Carpentier-Edwards prostheses were implanted in 84, 14, and 191 patients, respectively. There were 19 early and 64 late deaths. Mean follow-up was 5.04 +/- 1.03 patient-years. Fifty-eight patients (6.71% per patient-year) were reoperated on for degenerated prostheses, with 13 deaths. Twelve patients died without reoperation, and 17 await reoperation for degenerated valves. The rate of structural failure (total, 87 patients) was 21.07% and 3.04% per patient-year for patients less than and older than 20 years, respectively (p less than 0.001). The 6-year actuarial survival for these two groups was 50% and 68%, respectively. However, for patients 20 years old or younger, survival free from degeneration was only 20% at 6 years (p less than 0.001). Bioprostheses have a high failure rate and should not be implanted in young patients or in patients with a life expectancy exceeding 10 years.