Finite Element Analysis of Cardiovascular Stents

Abstract

The cardiovascular diseases have become contemporary and continuously growing healthcare problems. The main reasons for such problems are the intra-vessel depositions of plaque, cholesterol, etc., that give rise to thrombus formation, arterial blockage and stenosis. A traditional cure for said problems is to implant a stent. According to the “Guidance for Industry and FDA Staff - Non-Clinical Engineering Tests and Recommended Labeling for Intravascular Stents and Associated Delivery Systems”, an intravascular stent is a tubular structure intended for permanent implant in native or graft vasculature. The stent is designed to provide mechanical radial support after deployment. This support is meant to enhance vessel patency over the life of the device. Once the stent reaches the intended location, it is expanded by a balloon or self-expanding mechanisms described below. There are two types of stents: the so-called balloon-expandable stents and self-expanding stents. The balloon-expandable stents are expanded by a catheter. They retain the required diameter after deflation of the catheter. The self-expandable stents are expanded from the pre-deployed to the post-deployed diameter size in absence of a catheter. This can be a result of the properties of the material or/and geometry. This work presents the finite element analysis (FEA) of mechanical behavior of balloon-expandable stents, produced from stainless steel 316L and Cobalt-Chromium alloy L-605.