The Hemodynamic Study Of Ruptured Intracranial Aneurysm Using Fluid-structure Interaction Simulations

Objective:The relative hemodynamic parameters and mechanics of ruptured aneurysm with computational fluid dynamic simulations method were explored to provide theoretical support for the prediction on aneurysm rupture risk and treatment.Methods:Age,sex,smoking and alcohol habits,history of diabetes and hypertension,Hunt-Hess grade,transcranial doppler(TCD),the location of ruptured points observed at the time of clipping,and a 3D rotational angiographic set of images were collected in this retrospective study.The vascular and aneurysm models were constructed to identify the sizes,shape and location of aneurysm with 3D reconstruction technology.Computational fluid dynamic simulations with ANAYS software were performed to compute the hemodynamic parameters involving wall shear stress(WSS),shear stress oscillation index(OSI),and blood flow velocity(BFV).The observation results of rupture points and blood flow dynamics simulation parameters were compared together to elaborated the characteristic of hemodynamics parameters and the relationship between the location of rupture points and hemodynamics parameters.Results:About 54 anterior communicating aneurysms,77 posterior communicating aneurysms,and 28 middle cerebral aneurysms were diagnosed in the Affiliated Nanchong Central Hospital of North Sichuan Medical College from January 2018 to June 2019.Sixty cases had a microsurgical clipping procedure by the same doctor,while only twenty-one rupture points were identified in 21 patients.In the 21 cases,the averaged WSS of the rupture point was 0.215±0.047Pa,which is significantly lower than that(0.464±0.148Pa)of the aneurysm sac(t=6.897,P<0.001).No significant difference in OSI was found between the rupture point and the aneurysm sac(t=1.853,P=0.079).The average OSI is 0.035±0.024 for at the rupture point and 0.030±0.016 for at the aneurysm sac.Conclusion:The hemodynamic characteristics of the rupture point are different from that of the aneurysm sac.Lower WSS at the rupture point was observed and may be associated with the risk of intracranial aneurysm rupture.