Bjork-Shiley cardiac valves long term results: Winnipeg experience

Between April 1970 and December 1984, 1183 Bjork-Shiley cardiac valve prostheses were implanted in 915 patients (470 males, 445 females). Four types of valves were used; Delrin disc prostheses in 75 patients, pyrolytic carbon spherical disc valves in 645 patients, the 60 degrees convexo-concave disc model in 197 patients and the 70 degrees model in seven patients. Isolated mitral valve replacement was performed in 278 patients, isolated aortic valve replacement in 363 and double valve replacement in 153. Concomitant surgery was performed in 121 patients, including a modified Bentall procedure in 15. Perioperative mortality was 6.4% (nine patients undergoing isolated aortic valve replacement; 16 in mitral valve group, 18 with double valve replacement and 16 undergoing concomitant surgery). The cumulative follow-up was 4592 patient-years, to a maximum of 15 years. There were 130 late deaths, 60% due to cardiac events. Actuarial survival for the mitral valve group was as follows: four of six patients with Delrin disc valves were alive at 13.4 years; in the pyrolytic group, survival was 82% at 10 years; in the 60 degrees convexo-concave group survival was 87.5% at seven years. In the aortic valve replacement group, 83% of patients with pyrolytic valves were alive at 10 years and 85.7% of the 60 degree convexo-concave group were alive at seven years. For patients undergoing double valve replacement, 72% were still alive after seven years. Thromboembolic events averaged 1.4 per 100 patient-years. There were seven complete valve thromboses in the mitral position requiring reoperation; six of these patients were long term survivors.(ABSTRACT TRUNCATED AT 250 WORDS)