3D Printing and Characterization of the Biodegradable Vascular Stent

Abstract

Vascular stent is an important kind of medical device for the treatment of the vessel occlusion. In this work, we designed and fabricated a kind of biodegradable vascular stent. The dynamics of expanding, compressing and bending process for the single "sine", "60 degrees sine" and "U" type stent unites were analyzed with Finite Element Method (FEA) respectively, and furthermore, the expanding characters of polylactic acid (PLA) stent models with length of 4mm, 6mm, and 8mm were simulated. The "sine" type bracket had a better dynamic property and thus was more suitable for medical stent implantation in terms of mechanical properties. Then, the stent errors including the movement, the nozzle deposition and the shrinkage of the material were analyzed which provided experimental basis for the designing of the stent. The brachial artery stent implantation on pig experimental animals was carried out using the 3D printed PLA vascular stents. Results showed that the 3D printed vascular could be transported into the stenosis place and expand the vessel after pulling out of the balloon. The blood supply function was normal and the biodegradation could be observed after 30 days. This paper provided a novel method for clinical transformation of biodegradable vascular stents.