CLINICAL-PERFORMANCE OF BJORK-SHILEY MECHANICAL HEART-VALVES - A PERSPECTIVE ON OUTLET STRUT FRACTURES IN THE 60-DEGREES AND 70-DEGREES CONVEXO-CONCAVE DISK MODELS

The convexo-concave disc model of Bjork-Shiley mechanical heart valve is a significant improvement over the spherical disc model and compares favourably to other valves, including bioprostheses, with respect to hemodynamics, thromboembolism, anticoagulant related hemorrhage and prosthetic endocarditis. A small number of the 60 degrees and 70 degrees welded outlet strut Bjork-Shiley convexo-concave valves are at risk of sudden structural failure. The risk is constant or decreasing with time. Elective explanation is not recommended. The integral outlet monostrut 70 degrees Bjork-Shiley convexo-concave valve demonstrates further improvements in design and durability, and is recommended for use in patients who are appropriate candidates for mechanical cardiac prostheses.