Mechanical Characterization and In-silico Flow Analysis of a Flow Diverter

Abstract

Flow diverters have become an efficient and promising endovascular strategy for treatment of aneurysm. However mismatch in flow diverters’ mechanical properties with aneurysm morphologies can cause restenosis, late thrombosis, rupture of aneurysm and other vascular complications. The objective of this research is to develop functional relationship among mechanical properties of flow diverters, aneurysm morphologies and fluid dynamic parameters using silicon model. A transparent PDMS carotid artery model of 5.0-5.92 mm in diameter with varying sizes aneurysm (10 mm – 25 mm) was developed using lost sucrose casting method. Flow diverters were fabricated from metallic and polymer wire. The three main mechanical tests of flow diverter were three-point bend test using the expansion and compression testing machine with specially constructed metal holder. The radial and longitudinal tensile test using the Universal Testing Machine (UTM). Fluid tests using a micro-PIV were conducted to measure the velocity and the wall shear stress of a PED. The tests were specifically chosen to replicate the performance of the PED inside a living blood vessel. The results show that flexible, higher pore density and lower pore sizes can block the fluid into the aneurysm by 80%. These results can help better understand and use flow diverters for aneurysm treatment.