Insights into the formation and characteristics of leakage flow structures through bileaflet mechanical heart valve prostheses

The retrograde flow fields surrounding one hinge of Saint Jude Medical (SJM) and Medtronic Parallel (MP) bileaflet mechanical heart valve designs are studied. This study allows a detailed characterization of the washout capacity, squeeze flow, and leakage jets of each valve. The closing flow field of the SJM is found to be dominated by secondary flows, suggesting a scouring of nearby leaflet surfaces. In contrast, the closing flow field of the MP is more static, particularly around the hinge recess of this valve design. The comparative lack of reverse flow around the MP hinge recess may indicate a potential for entrapment or deposition of blood elements.