Hemodynamics of intracranial lateral aneurysms : flow simulation studies

Aneurysms develop as a result of abnormal dilation of a blood vessel due to vessel disease, trauma or congenital factors. A fully grown aneurysm can rupture and lead to cerebral hematoma and hemorrhage. In this research, lateral aneurysms of cerebral arteries were studied by simulation and experimental particle image velocimetry (PIV) analysis in glass models. Reynolds numbers of 100, 400 and 700 were used to characterize flow of blood in cranial blood vessels. Results indicate that rupture is likely on the dome or at the base of aneurysm that experience the impingement of flow. Higher shear stresses were noticed on distal end walls of the aneurysm in simulation. PIV results in glass models seem to suggest that the neck of an aneurysm acts in a way to redirect the blood towards dome. In-vivo, such redirected flows could influence the aneurysm growth and cause higher shear on the proximal walls. Thus, rupture could be localized on the walls of the aneurysmal dome where the flow velocities are absorbed or at the base region or where there is more shear.