Computer modeling of stent deployment in the coronary artery coupled with plaque progression

Abstract

© Springer International Publishing AG 2018. All rights reserved. In this chapter a complex problem of stent deployment with plaque formation and progression for specific patient in coronary arteries is described. Stent enables widening of the stenosed part of the blood vessel. We firstly describe state of the art for blood flow in the stented arteries. Blood flow simulation is described by Navier-Stokes and continuity equations. Blood vessel tissue is modeled with nonlinear viscoelastic material properties. The governing finite element equations used in modeling wall tissue deformation with emphasis on implementation of nonlinear constitutive models are described. Continuum based methods for modeling the evolution of plaque is derived. The LDL penetration is defined by the convection-diffusion equation, while the endothelial permeability is shear stress dependent. The Kedem-Katchalsky equations are employed for the coupling of solute dynamics and fluid dynamics at the endothelium while three additional reaction-diffusion partial differential equations are used for modeling the inflammatory process. The recruitment of macrophages is based on the probabilistic functions with cellular automata approach. Detailed software components for stent deployment and blood flow analysis are described. We present examples with rigid and deformable arterial wall with stented and unstented arteries. Effective stress analysis results for stent deployment are shown as well. As it can be noted, areas near the connectors between the stent struts are marked with the highest stress and these parts can undergo plastic deformation. Moreover, wall shear stress is considerably reduced after stent deployment due to the reduction of the narrowing and the opening of the artery.