[Finite element analysis of the expansion behavior of coronary stents].

Coronary stent is an important device used in Percutaneous Transluminal Coronary Angioplasty (PTCA) which is usually implanted to support the stenosed artery. Its expansion behavior depending on inflating of balloon and characters of recoil happening while the balloon is retrieved is the most important aspects which should be concerned in operation. In this paper, the finite element method was applied to systematically analyze the influence of strut width and thickness and the scale of dilatation of stent on its performance in expansion. The results show that increasing the strut width or thickness can improve the critical internal pressure needed for stent to expand fast. And the change of stent length while expanded is only associated with its structure and final dilatation state. If stent geometry is the same, it is the stent material that may be the main aspect to affect the recoil of stent. Experiment result is well consistent with simulation which indicates that the finite element method can substitute for the stent prototype testing to some extent.