One of the main problems that cause stenting procedures to eventually fail is a phenomenon called restenosis. Restenosis occurs when the internal arterial wall layer is injured due to stent expansion inside the artery, which triggers biological reactions that cause clogging of the artery and failure of the stent.
It is known from previous studies that there is a strong correlation between a stent`s mechanical properties and restenosis rates of the stented artery. One of the most important properties of stents is their radial stiffness, which strongly relates to the magnitude of the contact stress between a stent and an artery and can be used to estimate it.
This objective of this study is to provide a reliable analytical model for quick estimation of the elastic radial stiffness of different stents. Such a model can serve as a preliminary design tool of stents. An analytical model was developed for a family of self-expanding, open-cell, z-shaped stents. This structure is common for many stents used in peripheral arteries. The model is based on analysis of the elastic deflections of the stent`s struts.
The radial stiffness of several different stents and stent-grafts was evaluated using the analytical model and the results were compared against numerical (Finite Element Method) models and radial loading experiments. Good matches were found between all models. It is concluded that the analytical model provides relevant and usable estimates for the radial stiffness.
