Evaluation of Modified Oscillatory Shear Index and Recirculation Zone in a Deployed Coronary Stent

A major consequence of stent implantation is restenosis which occurs due to neointimal formation. There are several factors affecting restenosis among which wall shear stress plays a significant role. The present computational study of developing pulsatile flow through the entrance region of a deployed Palmaz stent in a coronary artery analyzes the local wall shear distribution and its effect on restenosis. A variation from low positive wall shear stress of around 10 dyn/cm² at the upstream of stent strut intersection to a very high positive wall shear stress of 300 dyn/cm² at strut intersection and then to a negative wall shear stress of −10 dyn/cm² at the downstream of strut intersection was observed. Modified oscillatory shear index was calculated which showed persistent recirculation at the downstream of strut intersection indicating it as a highly prone region to restenosis.