Ten-Year Results With Liotta Porcine Bioprostheses in the Mitral Position

The Liotta porcine bioprosthesis is a third generation bioprosthesis with a very low profile supraannular configuration with low-pressure glutaraldehyde-fixed tissue. Between May 1986 and December 1990, 670 patients underwent isolated mitral valve replacement with Liotta porcine bioprosthesis. There were 403 (60%) females and 267 (40%) males; the mean age was 39.03 ± 4.57 years (range, 16 to 75 years). The predominant lesion was combined mitral stenosis and mitral insufficiency in 46% of the patients. The operative mortality rate was 5.9% and the most frequent cause of the mortality was low cardiac output. Total follow-up was 3193.5 patient-years. The average follow-up period was 6.1 ± 2.5 years (range, 1 to 10 years). During the late period, 44 patients (1.4% per patient-year) died. The long-term survival estimate at 10 years was 84.8% ± 2.7%. Structural valve deterioration developed in 198 patients (6.2% per patient-year). Actuarial estimates of freedom from structural valve deterioration at 5 and 10 years were 87.6% ± 1.5% and 28.5% ± 4.5% and it was unrelated to sex or age. Most patients (88%) who developed bioprosthesis dysfunction underwent repeat valve replacement. The period between the implantation and development of structural valve deterioration was 5.9 ± 1.8 years for female patients and 6.2 ± 1.8 years for males (no statistically significant difference). We concluded from the early and high rates of structural valve deterioration in this young age group that the Liotta porcine bioprosthesis has limited long-term durability for mitral valve replacement.