Numerical simulation of atherosclerotic plaque growth using two-way fluid-structural interaction

Abstract

This paper presents a numerical investigation of plaque growth in a diseased artery using the two-way fluid–structural interaction (FSI) technique. An axis-asymmetric 45% stenosis model is used as the base model to start the plaque growth approximation. The blood is modelled as a non-Newtonian fluid described by the Casson model. The artery tissue is assumed to be a nonlinear material. The two-way FSI simulation is carried out in a way that mimics the unsteady blood flow through a diseased artery by using a pulsatile flow condition. After each flow velocity cycle, the numerical results are extracted and used to modify the stenosis geometry based upon critical wall shear stress (WSS) values and an accepted relationship between the concentration of low density lipoprotein and WSS. The simulation procedure is repeated until the growth- updated stenosis morphology reaches 79% severity. The behaviour of the flow velocity is analysed at each growth stage, together with the WSS, to determine the change of plaque morphology due to growth. The effects of WSS and pressure on the artery wall at the final stage (79% severity) of the plaque growth model are also compared with results from the authors’ previous work, to demonstrate the importance of the morphology change in plaque growth modelling. doi:10.1017/S1446181112000168