A Numerical Study of Stent Expansion

Abstract

Coronary Artery Disease (CAD) is mostly caused by the accumulation of fat and tissue in the artery walls and the obstruction of blood flow within the blood vessels. The narrowing of blood vessels results in symptoms of heart muscle weakness because there is not enough blood to feed. There are three methods of treatment for coronary artery disease including drug therapy, balloon dilation, and stenting (Percutaneous Transluminal Coronary Angioplasty (PTCA), and Coronary Artery Bypass Grafting (CABG) surgery). Several previous research studies found that the stent model created is based on the types of stents used in medicine. The aims of this paper are to conduct a simulation study of the interaction between the stent and the plaque attached to the blood vessels. The 3D model is created by SolidWorks and transferred to Ansys to perform structural analysis, and then the model is transferred to CFX to study the flow over the stent in the blood vessel using the Carreau fluid model. As for structure analysis, it was found that the results achieved using linear simulation and nonlinear simulation were not different. In the stent structure simulation, while the stent expanded over plastic deformation, the maximum stress was on the apex in both the linear and nonlinear studies. Obviously, the nonlinear simulation takes a lot of time to obtain the result when compared to the linear model simulation. The simulation result found that blood flow in the expanded stent is characterized as a loop that necks around struts; this might lead to stent vibration and harm to the blood vessels due to the loop of pressure along the stent length.