Numerical Simulation of Aortic Valve Leaflets Calcification Influence on Hemodynamic Performance Using Fluid–Structure Interaction Approach

Aortic valve calcification is the process of calcium buildup on the leaflets of the aortic valve, preceding functional insufficiency. Calcification underlies the development of aortic stenosis by stiffening the valve leaflets, leading to restricted aortic valve opening during systole and obstructed blood flow. However, a more comprehensive understanding of the hemodynamic effects of altered valve properties is required. Therefore, it is crucial to investigate the biomechanical properties of aortic valve leaflets susceptible to calcification. To examine fluid flow in an aorta segment with leaflets of different stiffness, a two-way fluid–structure interaction model was developed. The leaflet’s behavior was modeled using two constitutive laws—linear-elastic and isotropic hyperelastic—followed by numerical testing and comparative analysis. Using the material parameter values c01 and c10 within the ranges of 22–60 and 22–60 kPa, respectively, the hyperelastic model was examined. The valve leaflets’ Young’s modulus ranged from 1 to 22 MPa, while their Poisson’s ratio ranged from 0.35 to 0.45. A high correlation between Poisson’s ratio and wall shear stress was found. With an elastic modulus of 22 MPa and the highest Poisson’s ratio of 0.45, the maximum wall shear stress was 81.78 Pa during peak flow velocity and complete valve opening, while the lowest wall shear stress was 0.38 Pa. We can infer from the study’s results that, when considering the isotropic structure and nonlinear characteristics of valve leaflets, the Delfino hyperelastic model more accurately depicts their complex behavior.