Design and Biomechanical Analysis of a Novel Retrievable Peripheral Vascular Stent

Abstract

Structurally retrievable drug-eluting stents may have valuable clinical applications because they do not leave any foreign materials inside the patient's body. This article presents a novel design of retrievable peripheral vascular stent and the results from biomechanical analysis of its performance. Using the finite element analysis method, principal parameters of the stent were studied. Moreover, to ensure the practicability of the retrieval process, simulation, and in vitro experiments were performed. The retrieval force reached the maximum value when the whole retrievable part had been retrieved. Furthermore, the force was gradually increased during the retrieval process and remained constant after the main part had been retrieved. When the stent was being compressed, the maximum strain of the stent occurred at the connection between the stent's retrieval part and the main body part, at a value of 4%. The index of nonuniformity of the stent was too small to be counted both at the end of the compression and self-expansion processes. With the increase of moment, the bending stiffness (EI) of the stent decreased gradually. After bending moment was applied, the large strain region was mainly located in the stent's main body part rather than the retrieval part. The results of preliminary stent retrieval experiments demonstrated that the stent could be retrieved successfully. This novel retrievable stent displays promising biomechanical performance. The preliminary experiments demonstrated that the stent could be retrieved smoothly from the blood vessels.