Influence of geometric parameters on partial compressive force and pushing performance of flow diverter

Abstract

Research on flow diverter (FD) has progressed over the past decades; however, the relationships between parameters such as stent diameter, porosity, and number of wires and the properties of FDs, such as partial compressive force and push resistance, are not well understood. In this study, the partial compressive force and push resistance of braided FDs with varying porosity (61%-75%), diameter (2.5-5.0 mm), and number of wires (48 or 64) were evaluated using finite element analysis (FEA) and bench tests. At a small compression ratio, the 48-wire stents exhibited a larger partial compressive force than 64-wire stents of the same diameter. But when the compression ratio was 50%, the 64-wire stents had better resistance to pressure. The partial compressive force decreased as the stent diameter increased when all other parameters were equal. However, the influence of the diameter decreased as the stent porosity increased. The push resistance decreased as the porosity and diameter increased, and increased with the number of wires. These results provide useful information for FD design. Decreasing the number of wires can reduce the push resistance, while the push resistance is mainly influenced by the porosity and number of wires, and almost has no relationship with the partial compressive force. The FEA model proved very reliable, and corresponded well to the bench test results, which indicates that this model can be utilized to guide the design of FDs.