Primary failure of Hancock porcine bioprosthetic valves: two dimensional echocardiographic assessment

To reveal the process of primary failure of the Hancock porcine bioprosthetic heart valve, a real-time two-dimensional echocardiography was undertaken. There were 75 cases (84 valves) with 26 in the aortic valve position, 39 in the mitral valve position, 9 in both the aortic and mitral valve positions, and 1 in the tricuspid valve position. The subjects comprised 35 males and 40 females, whose ages ranged from 18 to 65 years with a mean of 44.7 years. Valvular changes such as thickened valve cusps or abnormal valve movement were observed in 27 (32%) of the 84 valves; more specifically, in 5 (14.3%) of the 35 aortic valves and in 22 (45.8%) of the 48 mitral valves, indicating that valvular changes occurred most frequently in the mitral valve position (p less than 0.01). In the period between valve replacement surgery and the appearance of valvular changes, no significant difference was noted between aortic and mitral valve bioprostheses. The duration ranged from 14.5 to 74.5 months with a mean of 50.2 months. Valvular changes were evident in more than 50% of the valve bioprostheses implanted 6 or more years ago. In the mitral valve position, valve cusp changes appeared more frequently at the anterior cusp than at the inner and outer cusps. The frequency was 17 cases at the anterior cusp, 6 at the inner and 9 at the outer. In 7 of the 11 cases followed up after the appearance of valvular changes, an increase in the changes was recognized 7.5 to 29.5 months (a mean of 16.4 months) later.(ABSTRACT TRUNCATED AT 250 WORDS)