Wall Elasticity Effects on Carotid Hemodynamics and LDL Mass Transport; a Computational Approach

Abstract

Cardiovascular diseases takes many lives yearly, whereas atherosclerosis is on the top. Carotid atherosclerosis disease considered as a multi-aspects disease and only by considering all of its aspects, a comprehensive insight can be achieved. It seems that wall motion has great effects on arterial hemodynamics and Low Density Lipoprotein (LDL)mass transport and concentration while LDL concentration is believed to be highly associated with atherosclerosis plaque formation. The primary goal of this study is to investigate the wall elasticity effects on carotid hemodynamics and LDL mass transport through carotid artery bifurcation as a challenging case due to its geometry and location. The blood is modeled as Carreau fluid which is considered as a well-behavior model for blood. A pulsatile speed profile applied as the inlet boundary and two-ways Fluid Structure Interaction (FSI) transient analysis is performed to achieve more accurate. In order to investigate wall elasticity effects, the carotid bifurcation modeled as solid, linear elastic and hyperelastic (Mooney-Rivlin). As the high LDL concentration can be considered as atherogenes is region indicator, therefore, it is used as the criterion for assessing the different arterial wall assumption. The wall elasticity effects on the hemodynamics are presented in three-time steps; early systole, end systole and end diastole. Results show that linear elastic and hyperelastic models predict very alike flow pattern however wall deformation and behavior are totally different. Results indicatet hat solid wall assumption is not appropriate for large and complicated arteries such as carotid bifurcation. Hyperelastic model (Mooney-Rivlin) seems more relevant and one the second place, the linear wall elastic model may be a good choice.