Simulation of bileaflet mechanical heart valves flow dynamics

Abstract

The major disadvantage associated with the implantation of mechanical heart valves (MHVs) is the need for life long anti-coagulant therapy to prevent complications from thrombosis. Such patients with valve implants are affected by an increased risk of bleeding, infection and/or autoimmune response. High blood flow through the mechanical may activate blood elements and initiate platelet aggregation, which will lead to thrombos formation. Understanding hemodynamics of mechanical heart valves play a key role in the performance assessment and valve design. In this work, we developed a numerical method to evaluate a full three-dimensional simulation of a bileaflet mechanical heart valve implanted at aortic position. An arbitrary Langrangian Eulerian (ALE) solver has been used to simulate the blood flow subjected to the moving valve leaflets. The leaflets are assumed tobe non-deformable and that their periodic motions are prescribed. We are able to show the complex 3D fluid structures downstream of the leaflets. Fluctuating wall shear stress was observed along the leaflet surface during the cardiac cycle. The solution yields a dynamically complicated vortical flow structures downstream of the heart valve. The significance of this study is to allow the development an accurate computational model to serve as a tool to access the hemodynamic characteristics of artificial heart valves.