Realistic finite element-based stent design: the impact of balloon folding

At present, the deployment of an intravascular stent has become a common and widely used minimally invasive treatment for coronary heart disease. To improve these coronary revascularization procedures (e.g. reduce in-stent restenosis rates) the optimal strategy lies in the further development of stent design, material and coatings. In the context of optimizing the stent design, computational models can provide an excellent research tool. In this study, the hypothesis that the free expansion of a stent is determined by the unfolding and expansion of the balloon is examined. Different expansion modeling strategies are studied and compared for a new generation balloon-expandable coronary stent. The trifolded balloon methodology presented in this paper shows very good qualitative and quantitative agreement with both manufacturer's data and experiments. Therefore, the proposed numerical expansion strategy appears to be a very promising optimization methodology in stent design.