Numerical Analysis of Coronary Stent Alloy Materials During Radial Expansion

Abstract

Atherosclerosis has been increasing rapidly in the past couple of decades. To treat this pathology, a stent with an expandable balloon has been mostly utilized among all other techniques. However, the performance of the stent is predominantly contingent upon the materials that are utilized for stent development. Though stainless steel and Co-Cr are used the most in stent manufacturing, there has been the development of new prospective biomaterials, mostly alloys, for coronary stent deployment. In this paper, four different alloys have been selected as those materials are considered to have better properties. The behavior of disparate alloy materials such as Co-Cr, AZ31, WE43 as well as Fe-Mn-Si unprecedentedly in stent development is studied through Finite Element Simulation in COMSOL Multiphysics. For the simulation, Palmaz- Schatz model is used and performance properties of the stent after simulation including stress distribution, dogboning, foreshortening along with recoil are evaluated. With the results of the simulation, it is perceived that WE43 is exhibiting better performance during and after stent expansion than other material alloys. It has lesser Von misses stress (400 MPa) with the lowest dogboning (0.48) and medium ranged foreshortening (-0.29) compared to other material alloys. AZ31 is observed to have shown closer results to WE43 due to their similar mechanical properties. Therefore, WE43 along with AZ31- these Mg alloys can be used as stent materials alongside commercially used materials because of their better performances, with the requirement of testing it experimentally beforehand.