Investigation of Plaque Effects on Cardiovascular Stent System

A 3D composite stent model, which consists of the stent, plaque, and artery wall, is generated to characterize stent transient expansion and deflection behavior using Finite Element Method (FEM) approach. Two types (flat and central-thicker) of plaque models have been employed to evaluate the geometrical effects of atherosclerotic artery on the cardiovascular stent deployment system. Simulation results demonstrated that the artery wall sustained a higher value of stress near the distal end of stent for both plaque models. In addition, the dog-boning factor increased significantly (more than 20-fold) and artery injury index was much higher for the central-thicker model. Comparatively, the effects resulted from the foreshortening, recoil rate and expansion rate were much less profound for both plaque models. However, the expansion rates for both plaque models did not meet the requirement of clinical practices. Further study to include plaque rupture mechanics for overcoming the shortcoming of the current models is currently proceeding.