Computational fluid dynamic studies of endovascular stents for treating cerebral aneurysms
MetadataShow full item record
Endovascular stents provide a potentially viable treatment paradigm for cerebral aneurysms by modifying their hemodynamics. To understand how different endovascular stent designs and number of stents used can differentially influence the hemodynamics in cerebral aneurysms, various stent designs and series of sequential stent placements were investigated. In addition to this, an asymmetric stent designed to block strong inflow jet in an anterior cerebral artery aneurysm of a specific patient geometry was simulated. To evaluate the effect of the endovascular interventions such as porous stents and an asymmetric stent on aneurysmal flow dynamics, we "virtually" implanted those into the idealized aneurysm models as well as patient's aneurysm models and performed Computational Fluid Dynamics (CFD) analysis. The stents were computationally deformed to fit into the vessel lumen. The hemodynamics of untreated and various stented aneurysms models were compared. We found that stent design strongly influences stasis at low vessel curvatures, but at high curvatures both stents did not significantly increase stasis. While aneurysmal stasis seemed to be mainly influenced by the design of the mesh struts in our study, the aneurysmal WSS was more influenced by the design of the mesh holes. Aneurysm hemodynamic parameters were significantly modified by placement of multiple stents. Stent placement lowered the wall shear stress in the aneurysm, and this effect was increased by additional stent deployment. The influence of stent design on hemodynamic parameters was more significant in double-stented models than the other models. It was found from CFD of the patient aneurysm that the asymmetric stent effectively blocked the strong inflow jet into the aneurysm and eliminated the flow impingement on the aneurysm wall at the dome. CFD analysis can offer a useful tool for predicting the effect of stent on aneurysm hemodynamics and evaluating various stent placements.