MORE THAN 10 YEARS FOLLOW-UP OF THE HANCOCK PORCINE BIOPROSTHESIS IN JAPAN

From February 1975 through October 1981, 256 Hancock porcine bioprostheses (Johnson & Johnson Cardiovascular, King of Prussia, Pa.) (60 aortic, 169 mitral, and 27 pulmonary/tricuspid position) were implanted in 220 patients (104 male and 116 female, aged 9 to 67 years; mean 43.3) at Kyushu University Hospital in Japan. The procedures include 41 aortic valve replacements, 121 mitral valve replacements, 4 pulmonary valve replacements, 6 tricuspid valve replacements, and 48 combined valve replacements (31 aortic plus mitral, 13 mitral plus tricuspid, and 4 aortic plus mitral plus tricuspid). Hospital mortality was 6.4 %. Follow-up was 98 % during 8 to 14 (mean 10.5) years. Cumulative follow-up was 1836 patient-years and 2078 valve-years. At 10 years the overall actuarial survival rate, including hospital mortality, was 70 % +/- 3 %, and freedom from valve-related mortality with sudden death was 87 % +/- 3 %. More than half of the current survivors required no anticoagulant therapy. Freedom from thromboembolism or anticoagulant-related hemorrhage (or both) and prosthetic valve endocarditis was common. Freedom from structural valve failure and reoperation declined more than 9 years after replacement of left-sided heart valves but not after replacement of right-sided heart valves. Sixty-seven patients underwent 68 repeat operations, and there were four deaths (5.9 %). The rate of freedom from overall valve-related complications at 10 years was 62 % +/- 8 % for aortic valve replacement, 53 % +/- 5 % for mitral valve replacement, 80 % +/- 13 % for pulmonary/tricuspid valve replacement, and 42 % +/- 9 % for combined valve replacement. There was a significant difference between pulmonary/tricuspid valve replacement and combined valve replacement (p < 0.05). The Hancock bioprosthesis is suitable for the replacement of valves in the right side of the heart but not for combined valve replacement.