RETRIEVAL ANALYSIS OF MECHANICAL HEART-VALVES - IMPACT ON DESIGN AND CLINICAL-PRACTICE

Explanted mechanical heart valves were examined nondestructively, and the findings were related to guidelines, technical reports, and other information to judge the risk of failure and its possible impact on va lve design and clinical practice. Diagnoses for single valves could be made, but risks and rates of failure for patient populations could no t be predicted due to insufficient information concerning the manufact uring process and valve and patient numbers. Eased on the results of t his study and the principle that decisions on recalls and patient coun seling must be based on scientific knowledge rather than on wait and s ee policies, the following is recommended: registration of all implant ed valves, follow-up of a large cohort of valve carriers, comparison o f wear test results of preimplant and postretrieval valves, maintenanc e of a reference stock of valves and materials, and submission of fail ure scenarios to certifying bodies.