Effect of Strut thickness on the Inflation Behaviour of Coronary Artery Stent using FEM

Abstract

Abstract Stent implantation is one of the most accepted method in treating coronary artery diseases due to their simplicity and faster patient recovery. Coronary stents are highly patient specific and the implantation success greatly relies on the design and clinical procedure. Studies confirm that, performance characteristics like radial strength, maximum expansion, stress concentration, recoil etc. are highly governed by the physical design of the stent. This paper focuses on finite element analysis using ABAQUS package to investigate the effect of varying strut thickness on the expansion behavior of a commercially available coronary stent. Envision Scientific Coronary Stent was adopted for this study. Total of five stent designs, one with actual size, two models with a strut thickness lesser than actual thickness and two with higher values were considered. The expansion behavior of the models under consideration was compared to the model with original dimensions. It may be noted that the thickness is one of important design parameter that affects the expansion and stress directly. With 15% reduction in thickness, the expansion increases by 10%. While, for an increase of 15% in thickness resulted in decrease in expansion by 10%. It may be noted that the percentage of increment in stress is linear and inversely proportional. Whereas, the increment in expansion is non linear and is minimal for low thickness. The present approach can be used for selecting the design parameters of stent to arrive in an optimum design.