Computational Fluid Dynamics And PIV Measurements Of Stent Interventional Therapy For Intracranial Aneurysms

The interventional therapy of intracranial aneurysms affects the hemodynamic effects of the aneurysm cavity.The development of stent therapy also promotes the development of new intracranial aneurysm stents.The flow resistance of stents of different structural shapes influences blood flow.One of the factors.In this paper,three kinds of low-porosity stents with different structure types were designed,and the hemodynamics of intracranial aneurysms treated with each stent were numerically simulated by flow-structure coupling to compare the effects of different stents for the treatment of intracranial aneurysms.This article selected a patient with intracranial aneurysm,and reconstructed a three-dimensional model of an individualized intracranial aneurysm using CT angiography data,combined with medical imaging technology and reverse engineering techniques,and applied fluid-solid coupling numerically using ANSYS CFX 15.0.Simulated calculations analyzed the changes in hemodynamic parameters during a cardiac cycle.For the individualized aneurysm model,three stents with the same mesh cross-sectional size,approximately equal permeability,and different structural shapes were designed.These three stents were implanted into individualized intracranial aneurysm models before and after stent implantation.The resulting hemodynamic changes were compared.The calculation results show that in one cardiac cycle,the blood flow impact on the downstream part of the neck of the aneurysm is the largest,and the turbulent phenomenon occurs in the tumor cavity due to the high-speed flow of blood.The high wall shear stress and wall pressure area are also concentrated on the tumor.In the neck region,the wall shear stress in the tumor cavity is relatively small,and the largest deformation area of the aneurysm is located at the top of the tumor.With the gradual increase of the elastic modulus of the aneurysm,the deformation of the wall surface showed a significant decrease,and the influence on the blood flow velocity and wall shear stress was small.After stenting,the overall flow conditions have been significantly improved.Periodic stents have maximally weakened the blood flow velocity in the neck and the tumor cavity.Thespiral stent implantation has resulted in a high wall cut in the neck of the aneurysm tumor.The stress completely disappears and the improvement is best.Wall pressure and wall deformation in the tumor cavity were reduced to varying degrees,of which the interventional treatment of the periodic stent was the best.In combination with rapid prototyping technology,a fully transparent three-dimensional intracranial aneurysm silicone model was constructed,and three kinds of stents were modeled.The particle flow velocity technique was used to accurately measure the flow of the stent before and after the aneurysm silicone model.The experimental results verify the applicability and accuracy of the numerical calculation method.The conclusions of this study can provide a certain reference for accurately predicting the rupture risk of aneurysms and designing and optimizing the stent structure.