A NEW RING STENT WITH GRADED GEOMETRY FOR TREATING COARCTATION OF CURVED AORTA ARTERIES

Abstract

Ring stent implantation has been widely used to treat coarctation of the aorta (CoA) as an alternative to surgery. Currently adopted stents with uniform geometry may cause uneven stress distribution and high stress concentration in curved vessels, leading to in-stent restenosis (ISR). Inspired by functional graded material, here we propose a new ring-and-link stent, which has graded geometry in order to achieve a reduced peak stress when deployed in curved arteries. Numerical simulation of a single ring of the graded stent indicated that by varying the circumferential spacing of wave crest, the maximum stress exerted on the artery was reduced by as much as 27.86% in comparison with the uniform one. The effects of stent geometric parameters and artery curvature were also obtained through a parametric study. Finally, a whole stent was studied to verify the design, and a maximum stress reduction by 31.96% was achieved. In summary, the proposed graded ring stent shows great potential in clinical applications to reduce the risk of ISR.