Hemodynamic Analysis of Aortic Valve Stenosis via Fluid-Structure Interaction Modeling

Aortic valve stenosis is a prevalent cardiovascular disease characterized by the narrowing of the valve orifice, which restricts blood flow and leads to elevated flow velocities and shear stresses. Modeling the complex motion of the valve leaflets during the cardiac cycle and their intricate influence on hemodynamics remains a significant challenge. Hence, the progression of hemodynamic abnormalities and their relationship to stenosis severity are not fully understood, while critical for early detection and intervention. To address this, a fluid-structure interaction (FSI) model was developed to replicate the leaflet motion and flow dynamics in stenotic aortic valves. Structural simulations were performed using Ansys Mechanical APDL, while fluid dynamic simulations were solved in Ansys Fluent, with both domains coupled via the Ansys System Coupling module. Furthermore, the valve stiffness was assigned according to vary Young's modulus from 2 to 20 MPa, representing healthy to severely calcified valve conditions. A pulsatile plug velocity profile from the literature was prescribed at the inlet, and simulations was conducted over an entire cardiac cycle. The model demonstrated strong agreement with experimental data from the literature, accurately capturing velocity profiles, peak velocities, and turbulent flow features. As stenosis severity increased, the valve jet became more constricted, while the downstream recirculation region enlarged. In addition, the wall shear stress (WSS) and pressure distributions also aligned well with the existing findings. This modeling approach enhances the understanding of the hemodynamic effects on aortic valve stenosis and offers valuable insights for future clinical assessment and intervention strategies.