A New Approach for Assessing the LDL Species in Arterial Wall Layers

Abstract

In the present study, a numerical model for the convective and diffusive transport of LDL in various layers of the arterial wall is developed. The transport in the lumen, endothelium, intima, internal elastic lamina, and media of a straight axisymmetric arterial segment has been considered in the model. The endothelium, intima, internal elastic lamina (iel), and media have been considered as a homogeneous porous media. Navier–stokes equation and Darcy’s equation have been used for modeling the fluid flow in the lumen and the arterial wall, respectively. The mass transport in the lumen has been implemented through the convective–diffusion equation, whereas volume-averaged convective–diffusion–reaction equation has been used for modeling the mass transport through porous layers. The relevant physiological parameters have been taken from various studies. Fluent 12.1 has been used for the solution and analysis of the problem. This study demonstrates that this numerical model can be used efficiently for evaluating the distribution of concentration of LDL in the different layer under the conditions of high LDL concentration in blood (hyperlipidemia) and hypertension. Finally, a new approach for estimating the possible LDL species depositions rate in intima and media layers has been presented. This may demonstrate a possible prediction for extent of progression of the disease with respect to available clinical parameters. The results have shown that rate of accumulation is higher in the intima layer than media layer and pointed out intima layer as a possible prone location of plaque formation. The results also have indicated that both the clinical parameters hypertension and hyperlipidemia are responsible for higher deposition rate of LDL species in intima and media.