Wall shear stress and low density lipoprotein concentration in stented arteries

Abstract

Current computational analysis results quantify Wall Shear Stress (WSS) and its impact on Low Density Lipoprotein (LDL) concentration of a fully deployed straight artery stent. Atherosclerosis shows predilection in arterial regions with hemodynamic particularities, as local disturbances of WSS in space, and locally high concentrations of lipoprotein. The WSS and subsequently the LDL distribution are important indicators of stent performance. A typical 6.0 mm diameter straight stented artery is used to elucidate the WSS and the LDL transport under steady flow conditions treating the blood as a non-Newtonian fluid. Struts are 50.0 % embedded into the arterial wall. Emphasis is placed in the LDL distribution at the upstream and downstream flow regions of each strut intersection. Reduced WSS values are observed towards outlet. At the strut intersections, high WSS values are observed possibly causing platelet activation. Prone to plaque development are flow regions located at specific strut intersections (mostly at the vicinity of the curved struts) where increased LDL concentration is observed. The maximum LDL concentration over the stented artery reaches a value of 3.8 % higher than that at the entrance. The concentration at distal to any strut region was higher than proximal to the strut.