Investigations of the thrombogenic and cavitational potentials of a bileaflet mechanical heart valve, using ANSYS-CFX

Detailed flow dynamic analysis in the vicinity of the leaflets and the housing during the valve-closure phase (including the rebound) is of interest for the assessment of both the thrombogenic and the cavitational potential of a candidate valve. A newly developed lumped parameter model of the left ventricle contraction and a computational fluid dynamics (CFD) representation of the fluid structure interaction (FSI) are coupled, allowing for the investigation of the valve closure under different conditions. The platelet activation potential is related to the velocity profile in the clearance region and to the duration for which the platelets are exposed to wall shear stress (WSS). The cavitational potential is related to the negative pressure transients at the leaflet edge and to the vorticity of the flow during valve closure and rebound.

I. Introduction

Mechanical heart valve implant is a common treatment no-wadays, but patients with these implants need to be under longterm anticoagulant therapy in order to minimize problems related to thromboembolic complications [3]. Cavitation bubbles development due to the large negative pressure transients on the inflow side of the leaflet edge and their subsequent collapse may contribute to both the platelet activation and the structural damage of the valve [2].