Numerical investigation of the effect of hypertensive blood pressure on cerebral aneurysm - Dependence of the effect on the aneurysm shape

Fluid-structure interaction (FSI) computations of two cerebral aneurysms are carried out under hypertensive and normotensive blood pressures. Hypertensive blood pressure is one of the major risk factors in subarachnoid hemorrhage, which is mostly caused by the rupture of cerebral aneurysm. Since hemodynamic wall shear stress (WSS) is known to play an important role in aneurysm progression, investigating the WSS distribution in conjunction with hypertensive blood pressure is expected to provide a better understanding of aneurysms. The WSS distributions obtained from the simulations show that hypertensive blood pressure considerably affects one of the subjects but not the other. The effect is a wider spreading of the high WSS region on the aneurysm wall, which prevents the wall from weakening. It is also shown that the deformation of the aneurysm wall can alter the flow patterns in the aneurysm to diminish the stagnant flow near the apex, which is linked to the weakening of the wall. The effect of hypertensive blood pressure and wall deformation is shown to be highly dependent on individual aneurysm geometry, and that stresses the importance of subject-specific simulations.