Fluid–structure computational analysis to investigate the link between early atherogenic events and the hemodynamic environment in an experimental model of intimal thickening

The main hemodynamic forces acting on the vessel wall are the wall shear stress (WSS), caused by the friction of the flowing blood on the endothelial surface, and the circumferential stress caused by blood pressure, acting on endothelial cells and on smooth muscle cells. Experimental studies on the effects of disturbed flow contribute to our understanding of the pathophysiological mechanisms of vascular diseases, helping in ameliorating therapeutic interventions. The perivascular placement of a silastic collar around the carotid artery represents an established model of intimal thickening in rabbits and mice for testing mechanistic hypothesis on the pathogenesis of atherosclerosis and for assessment of anti-atherosclerotic interventions. In this work we adopted a one-way coupled, fluid-structure interaction approach to investigate the immediate fluid-dynamic alterations induced by perivascular collar placement on rabbit common carotid artery and establish a correlation between the early atherogenic events and the modifications of the hemodynamic environment. The results from this computational study help quantify the role of the local fluid-dynamics among the possible factors promoting the atherogenic processes in this experimental model. In particular, values of WSS and circumferential stress lower than in the physiological situation were found in the arterial region between the two collar-vessel contact points.