Simulation Of Intervention For Sinuous Aneurysms With Different Structural Stent

As a minimally invasive treatment technique, endovascular stent intervention technology has been accepted by modern medicine, which has broad prospective for development. However, the efficacy of stent intervention is affected by many factors, including the stent shape (spiral, grid, etc), cross-section of stent wire, porosity, stent placement, stent connector, stent flexibility and so on.Endovascular stents with different stent shapes or wire cross-section shapes have different effects on the hemodynamics of basilar aneurysms. In order to get quantitative understanding of this kind of difference, geometrically virtual models of three-dimensional sinuous aneurysms and four types of mesh stents (different porosity and different wire cross-section shapes) were constructed using CAD software, and simulations of stented and nonstented models were performed respectively using finite element software ANSYS11.0 according to CFD method. Hemodynamics data were extracted and analyzed in terms of flow field, pressure and wall shear stress.The result demonstrated that the velocity of blood flow in stented model is greatly weaken than the nonstented model, and the pressure along the wall of the distal aneurysm is also decreased and more uniform, and the locally elevated WSSs at the proximal lip of the distal aneurysm disappeared, instead small and uniform WSSs distribute along a majority of the aneurismal wall after stent intervention.It can be concluded that the new type of trianglualr stent with lower porosity has more superiority than other stents in weakening impact of blood to aneurismal wall and decreasing local high pressure and WSS. The flow resistance of the new stent with triangular cross-section is different when blood flows in and out of the aneurismal sac, and thus brings about different hemodynamics in aneurysms after the stent intervention. The stent with triangle section is more suitable for sinuous basilar aneurysms comparatively. The present study can provide some theoretical guidance to structural design of endovascular stent.