Finite element structural analysis of self-expandable stent deployment in a curved stenotic artery

Abstract

A self-expandable stent is a tube-like structure that is expanded into the stenotic arteries to normalize the blood stream. Selfexpandable stents are expected to have superelastic properties of restoration after mechanical strain, restoring capability by at least 5% since the stents in operation may suffer large deformations, as each is folded and crimped into a catheter for insertion into a stenotic area in an artery and expands to the original diameter of the artery. Therefore, the shape of a stent is an important factor to control its desired tension and flexibility. In the present study, as a basic step to model the geometry of a stent and to design parameters for stent performance development, finite element analysis of a typical self-expandable stent was conducted to understand stent influence on arteries and plaques. A numerical analysis model to predict the stress and strain of the artery and plaque is presented with three steps of stent operation: Crimping the stent in a catheter, positioning the catheter in the stenotic area, and deploying the stent inside arteries with three different curvatures (κ = 0, 0.2 and 0.4). The results of this study showed the influence of the geometry of commercially available stents on an artery with plaque and the radial direction of plastic deformation of the plaque, which indicates the recovery of the stenotic artery.