Abstract
We have developed a novel microporous covered stent (MCS) for the endovascular embolization treatment of intracranial aneurysm (IA). This stent promotes progressive thrombosis by flow divertion and facilitates IA embolization treatment by clotting of whole blood in the IA. However, difference of geometric configuration of each aneurysms affects the performance. In this study, we investigated intra-aneurysmal flow with various aneurysm position at a curved parent vessel by using in-vitro flow simulator. The IA models were placed at the outer-sidewall at the U-bend parent vessel, of which curvature was as same as that of human carotid siphon. The IA opening position on U-bend vessel was located at θa = 30, 60, 90, 120, 150 and 180 deg. Reynolds number of the parent vessel flow was set at 190 - 970 to simulate CCA blood flow. Microporous sheet (pore diameter: 100μm, aperture ratio: 30%) was placed as a model of a MCS at opening of IA. Flow velocity field at the IA model were measured by PIV. As the results, by MCS stenting, volumetric mean share rate (VMSR) in IA model became about 15 times smaller than before stenting. Dimensionless VMSR was increased proportionally by dimensionless IA in-coming/out-going flow rate increasing. These results suggest that our developed MCS has one of the best embolization device for IA therapy and is expected high embolic effects due to obstruction of direction flow in aneurysm.
