2D and 3D multi-physics models for flow and nonlinear stress/strain analysis of stenotic arteries with lipid cores

Abstract

It has been hypothesized that critical artery stress and strain conditions may be used as indicators to predict possible plaque cap rupture and subsequent onset of cardiovascular diseases. Multiphysics MRI-based 2D nonlinear models are idealized—but yet fairly realistic— nonlinear 3D models based on in vitro experiments with fluid-structure interactions (FSI) and structure-structure interactions (SSI) are introduced and solved by ADINA to perform flow and stress/strain analysis for stenotic arteries with lipid cores. The Navier–Stokes equations are used as the governing equations for the fluid. Hyperelastic Mooney–Rivlin models are used for both the arteries and lipid cores. MRI-based 2D solid models using real patient data, idealized 2D solid models for an eccentric tube with lipid cores, 3D solid and FSI models for tube with asymmetric stenosis, and a lipid core are studied. The results indicate that artery plaque stress/strain distributions are affected considerably by material properties, axial pre-stretch, pressure conditions, lipid core material property, size, position and geometry, and fluid-structure and structure-structure (vessel wall and lipid core) interactions. Sharp angles of lipid cores and thinner plaque cap lead to peak wall stress/strain and may be linked to possible plaque cap rupture.