The design of coronary stents has evolved significantly<br/>over the past two decades. However, they still face the<br/>problem of in-stent restenosis, formation of neointima within<br/>12 months of the implant. The biological response after stent<br/>implantation depends on various factors including the stent<br/>geometry which alters the hemodynamics. This study takes<br/>five different coronary stent designs, used in clinical practice,<br/>and explores the hemodynamic differences arising due to the<br/>difference in their design. Of particular interest is the design<br/>of the segments (connectors) that connect two struts.<br/>Pulsatile blood flow analysis is performed for each stent,<br/>using 3-D computational fluid dynamics (CFD), and various<br/>flow features viz. recirculation zones, velocity profiles, wall<br/>shear stress (WSS) patterns, and oscillatory shear indices are<br/>extracted for comparison. Vessel wall regions with abnormal<br/>flow features, particularly low, reverse, and oscillating WSS,<br/>are usually more susceptible to restenosis. Unlike previous<br/>studies, which have tried to study the effect of design<br/>parameters such as strut thickness and strut spacing on<br/>hemodynamics, this work investigates the differences in the<br/>flow arising purely due to differences in stent-shape, other<br/>parameters being similar. Two factors, the length of the<br/>connectors in the cross-flow direction and their alignment<br/>with the main flow, are found to affect the hemodynamic<br/>performance. This study also formulates a design index<br/>(varying from 18.81% to 24.91% for stents used in this<br/>study) that quantifies the flow features that could affect<br/>restenosis rates and which, in future, could be used for<br/>optimization studies
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.