A Novel Metamaterial-Based Stent with Dual Properties of Auxetic and Self-Expanding

Abstract

Vascular stents have been widely used in various cardiovascular diseases associated with atherosclerosis, while the potential risks of in-stent restenosis (ISR) and stent thrombosis (ST) still restrict its further development. Here, by combining the self-expanding (SE) mechanism and auxetic metamaterial, a novel SE stent called MBS was proposed and systematically studied. Through the finite element (FE) method, a stent-artery coupling model was established to study the crimping, expanding, and pulsating behaviors of the proposed MBS. Results show that the MBS well retains various advantages, including a large recoverable strain, a large radial resistance force (RRF), and a smaller radial opening force (ROF). Meanwhile, due to the auxetic effect of the adopted re-entrant honeycomb, the MBS shows a significant negative foreshortening behavior, which can be designed from about -5% to about -50%. Besides, fatigue analysis also shows that all strain-based points are within the design criteria. Geometric parameter of RE cell shows a great effect on the comprehensive performance of the MBS, which needs a further optimal design for ideal radial force, foreshortening effect and fatigue performance. In conclusion, the novel design is expected to improve the mechanical properties of the traditional stent, which should be given more attention in further research.