Characterization of Explanted Bileaflet Mechanical Heart Valves and Correlation with Patients' Clinical Data

The analysis of explanted mechanical heart valves (MHVs) is an essential source of information about the effects of their in vivo working. In order to better understand the mechanisms arising from the interaction between MHVs and biological environment, in this study fourteen bileaflet valves were considered. From clinical data, all the malfunctioning valves showed a high degree of stenosis. By investigations on the MHVs components and the study of the clinical data, it was possible to establish that the ordinary abrasive wear does not involve clinical disease. On the contrary, impact wear and/or surface defects, due to improper surface finishing, can generate rough areas and consequently thrombogenic sites. The growth of fibrotic tissue can modify the cinematic coupling with serious alteration of the leaflet motion. This work demonstrates the feasibility of creating a database to statistically analyze the results with the aim of improving valves design and surgical operation.