Non-Newtonian Effects on Blood Flow Dynamics in Stented Coronary Artery Bifurcations

From clinical practice, it is known that coronary artery bifurcations are regions where the flow is strongly perturbed, and is prone to the development of atherosclerotic lesions. Bifurcation lesions have always represented a major challenge for placement of stents for treatment of stenosis. Conventional bare metal stents are mostly used in clinical practice of bifurcation lesion treatments since there is no specific commercially available stent dedicated for treating bifurcations. Stent design is strongly influenced by the specific hemodynamic conditions in a given vessel. Therefore, in principal, what was previously assessed for standard stent design, should be re-assessed for stenting bifurcations. In this paper a blood flow model for stented coronary artery bifurcation is presented. The non-Newtonian approach incorporating blood rheology under low shear rates is presented by employing Carreau model. Computational fluid dynamics modeling is used to adapt the model and characterize the non-Newtonian flow patterns and identify the hemodynamic factors that may influence the stent design. The results shows that the flow conditions and particularly shear stress distribution in the vicinity of stent struts and near arterial wall are significantly different compared to the usually assumed Newtonian flow conditions.