Parametric Design and Finite Element Simulation of Coronary Stents

The high prevalence of cardiovascular diseases has increased the demand for using different stents. To prevent instent restenosis, the design and fabrication of safer stents for coronary angioplasty is essential. However, prototyping and mechanical testing of new stent designs are challenging, time-consuming, and expensive procedures. Therefore, parametric models and finite element simulations are used to help designers improve stent designs. In this study, three commercially available coronary stents are parametrically designed and modeled based on their diameter, number of rings, number of peaks, and strut thickness. Moreover, a finite element simulation of the expansion of each model in the artery is performed to investigate the effect of links on stent function and vascular injury. The results demonstrate that the applied stresses on the stent during its placement in the coronary artery are beyond elastic limits, and the stent's material enters its plastic zone accordingly. The applied strain is less than the failure strain of the material. By comparing maximum Von-Mises stress, foreshortening, and dogboning of different types of stents, it can be concluded that the closed-cell stent is a safer model and causes fewer side effects regarding vascular injuries. However, open-cell stents provide more flexibility and can be advantageous in curved vessels. It is noteworthy that parametric modeling of stents can be beneficial in future studies and finite element analysis of stents for understanding the effect of the geometric parameters on stent function.