Preoperative in silico analysis of atherosclerotic calcification vulnerability in carotid artery stenting using Finite Element Analysis by considering Agatston score

Abstract

Abstract-The role of calcification inside fibroatheroma during carotid artery stenting operation is controversial. Cardiologists face a major problem of "plaque vulnerability" during the placement of both balloon and stent, with stiff plaques containing advanced calcifications that break the arterial wall or give rise to unstable thromboembolic stroke. The aim of this work is to evaluate the role of calcification (in terms of material and mechanical properties) in plaque vulnerability and wall rupture and to find plaque maximum resistance before breaking. Image-based models of carotid artery stenting were used and Finite Element Analysis (FEA) was performed to simulate the impact of balloon and stent expansion in the presence of calcified plaques. In detail, a nonlinear static structural analysis was performed on 20 patients acquired using in vivo MDCT angiography. The Agatston Calcium score was obtained for each patient and subject-specific local Elastic Modulus was calculated. The in silico results showed that by imposing maximum ultimate external load of 1.2MPa and 4.2MPa on balloon and stent respectively, average ultimate stress of 55.