Radial capacity and hemodynamics evaluation in vitro and implantable feasibility validation in vivo of thinner bioresorbable polymer vascular stents

Abstract The major issue of bioresorbable polymer vascular stents (BRPSs) is their insufficient radial capacity relative to metal stents. As a result, BRPSs are always designed with a larger thickness. However, the thicker struts substantially increase the risk of adverse events. Therefore, the clinical demand for thinner BRPSs is becoming increasingly urgent. In this study, we built on our previous research to develop BRPSs with only 100 μm thickness. Through in vitro experiments and numerical simulations, we evaluated the compression, expansion, vessel dilation processes, and hemodynamics of thinner BRPSs. We also validated the feasibility and benefits by in vivo experiments. The results demonstrated that during compression, expansion, and vessel dilation, the thinner BRPSs maintained sufficient Radial strength (RS) and decreased residual stress and plastic strain. They also mitigated intima damage, the recirculation region, and low wall shear stress distribution induced by stent implantation. In vivo experiments showed that thinner BRPSs effectively alleviated concerns related to thicker BRPSs, such as intimal hyperplasia, inflammatory response, and delayed endothelialization. In conclusion, the thinner BRPSs with 100 μm thickness in this study maintain adequate RS and reduce the risks of thicker stents, thereby exhibiting the potential for clinical application.