Characterizing Arterial Wall Properties with Plaque and Stent: Elastic, Viscoelastic and Hyper-elastic Models

Determining the mechanical characteristics of the artery is very essential for the production of vascular implants. In the present work, the mechanical characteristics of arterial walls were investigated by considering plaque and stent in a 3D model. This article aims to investigate the effect of the arterial tissue with the same boundary conditions and restrictions for an artery blocked with the plaque and stent, in creating stress in the tissue. An intravascular stent implantation is a treatment method whose success largely depends on the mechanical characteristics of each vascular component, plaque and stent, and blood flow pressure. For opening up the blood flow in the blocked artery, stents could be used as medical devices. In this research, a stent was designed, and its impact on all three models of elastic, viscoelastic, and hyper-elastic arterial tissue with plaque was studied and compared. An ideal finite element model was made to find the effect of three types of the artery tissue (elastic, viscoelastic, hyper-elastic) with the systolic and diastolic blood flow pressure to observe the stress and the deformation of arteries, plaques, and stents. In addition, for the hyper-elastic model, two Mooney-Rivlin and Ogden models were also investigated. It was found that the type of artery had an effective impact on the result of the stress and the deformation created in the stented artery. Moreover, the results illustrated that considering different models for the artery tissue affected the plaque and stent behavior. Arteries exhibit interesting mechanical behaviors. In the present study, an attempt was made to investigate different mechanical behaviors of arteries with the plaque and stent obstruction. In the examined models, the stress for the artery and plaque was higher in the Ogden model and the lowest one was in the viscoelastic model, and the deformation was higher in the viscoelastic model and lower in the Ogden model. It should be noted that the average stress for the vessel in the Ogden model was about 50% higher than the viscoelastic model. Pathological changes in the walls of the vessels can lead to high-risk cardiovascular diseases such as heart attacks and strokes. Understanding arterial mechanical behaviors provides valuable insight into disease. Therefore, the investigation of different behavioral models helps to evaluate the behavior of the arterial wall by considering the composition and function of the tissue.