Finite element analysis of the implantation of a balloon-expandable stent in a stenosed artery

Intracoronary stent implantation (ICSI) has been widely used in interventional procedures. It can induce an even greater increment in intervention effectiveness and in success rate than traditional percutaneous transluminal coronary angioplasty (PTCA). However, owing to the complexities in geometries, material properties and interactions seen in ICSI, analyses of the complete stenting system composed of balloon, stent, plaque and artery are limited. In order to investigate the biomechanical characteristics of ICSI, a three-dimensional model of the complete stenting system and self-defined constitutive models for the plaque and the balloon were developed, which made the simulation well close to the real situation. Finite element method (FEM) was used to simulate the stent implantation under the balloon inflation and deflation. The simulated results show that the distal end of stent, which tilts after expansion, may injure the artery wall. High stress concentrates in the contacting areas between the stent and the plaque. The recoil ratios of the balloon-stent model, the balloon-stent-plaque-artery model (representing ICSI) and the balloon-plaque-artery model (representing PTCA) are 3.1%, 12.3% and 22.9%, respectively. In conclusion, FEM can help illustrate and quantify some biomechanical characteristics of ICSI. And it would be helpful for the general understanding of ICSI.