Effects of Cardiovascular Stent Design on Wall Shear Stress Distribution in Straight and Curved Arteries

Abstract

he stent is a major breakthrough in the treatment of coronary artery diseases. The permanent vascular implant of a stent, however, changes the intra-stent blood hemodynamics. There is a growing consensus that the stent implant may change the artery wall shear stress distribution and therefore trigger the restenosis process. Several studies have suggested that low shear stress, particularly the shear stress less than 5 dyne/cm2, may lead to endothelial proliferation of smooth muscle cells. Computational fluid dynamics (CFD) has been widely used to analyze hemodynamics in stented arteries. In this paper, CFD models were developed to investigate the effects of cardiovascular stent design on the wall shear stress distribution in straight and curved arteries. Results show that the stent design pattern alone did not have a significant impact on the stent hemodynamics; however, stenting in curved arteries increased the low shear stress area which may lead to higher restenosis rate. The low shear stress area was almost doubled when the degree of artery curvature increased from 0o to 90o. The proposed methodology and findings will provide great insight for future optimization of stent design to reduce the risk of restenosis.