Prediction of strength and radial recoil of various stents using FE analysis

Abstract

The recent developments in engineering and technology over the past few decades have brought many devices that makes human life very comfortable and to cure acute ailments. In current life style, the probability of Coronary Artery Diseases (CAD) is very high even at the younger age throughout the globe. Coronary artery stent implantation is one of the effective and usually used strategies for treatment of coronary heart diseases. The main purpose for stent implantation is to provide mechanical support to the blood vessel wall. Thus, various mechanical properties of different stent materials become important parameters to design and select suitable stent. Inappropriate mechanical properties may cause harm to the vessel wall and in turn human life. This study provides a guideline to understand the mechanical behaviour of various stent materials generally used in terms of selected properties. Deformation behaviour has been studied numerically for various stents using Finite element analysis (FEA) to predict Equivalent Von-Mises Stress, Radial Recoil and Factor of Safety using ANSYS work bench software. Stent of different geometry are modeled using SOLIDWORKS and then structural analysis is performed on Stents of seven different materials viz. SS 316L Stent, Cobalt Chromium L-605 Stent, Bio-Degradable Stent (PCL), Nitinol Stent (Austenite), Elgiloy Stent, Tantalum Stent, Cobalt Chromium MP35 N Stent under normal blood pressure. The ‘Radial recoil’, Equivalent ‘Von-Mises Stress’ and ‘Factor of Safety’ of various stent materials using same stent design and same boundary conditions are compared. The results reveal that the L-605 Cobalt Chromium has low radial recoil and 316 L Stainless Steel is having highest factor of safety among the selected stent materials.