A Computational Fluid–Structure Interaction Study for Carotids With Different Atherosclerotic Plaques

Abstract

Atherosclerosis is a systemic disease that leads to accumulation of deposits, known as atherosclerotic plaques, within the walls of the carotids. In particular, three types of plaque can be distinguished: soft, fibrous and calcific. Most of the computational studies who investigated the interplay between the plaque and the blood flow on patient-specific geometries, used non standard medical images to directly delineate and segment the plaque and its components. However these techniques are not so widely available in the clinical practice. In this context the aim of our work was twofold: i) to propose a new geometric tool that allowed to reconstruct a plausible plaque in the carotids from standard images and ii) to perform 3D FSI simulations where we compared some fluid-dynamic and structural quantities among 15 patients characterized by different typologies of plaque. Our results highlighted that both the morphology and the mechanical properties of different plaque components play a crucial role in determining the vulnerability of the plaque.

The Need to Shift from Morphological to Structural Assessment for Carotid Plaque Vulnerability

“…Our results are consistent with those of previous studies [ 30 , 43 ] that highlighted the crucial role of considering both the morphology and the mechanical properties of different plaque components in addition to the degree of carotid stenosis in determining plaque vulnerability. Although the American Heart Association (AHA) has summarized a classification of atherosclerosis [ 51 ], the understanding of why such a morphological classification is linked with plaque vulnerability has not been fully illustrated.…”

“…The interaction between the blood domain and deforming arterial walls is not typically considered, and CFD simulations are usually restricted only to the blood flow analysis. However, fluid–structure interaction (FSI) models combining CFD with structural finite element analysis (FEA) have been provided to give a more accurate estimation of the real vascular system and have been used to assess both fluid dynamic and structural behaviors in human atherosclerotic carotid plaques [ 28 , 29 , 30 ].…”

Hemodynamic evaluation of endarterectomy and stenting treatments for carotid web

“…In addition, some studies considered fluid-structure interaction (FSI) modeling for stenotic carotids. Bennati et al studied the carotids with different atherosclerotic plaques using FSI ( 44 ). Gao et al performed stress analysis on four subjects with different plaque burdens by FSI simulations ( 45 ).…”

On the Choice of Interface Parameters in Robin–Robin Loosely Coupled Schemes for Fluid–Structure Interaction

“…FSI results could provide important clinical indications about the evolution of a disease or the improvement of a therapy. We mention, for example, studies that quantified the stresses in carotid atherosclerotic plaques [46,47] or compared different surgical strategies for coronary bypasses [48,49]. However, often the application of FSI methods in such contexts has been limited due to the very high computational effort needed to numerically solve such problem.…”