Computational and experimental studies into the hemodynamics of cerebral aneurysms

Rupture of cerebral aneurysms (CAs) is a major cause of life-threatening subarachnoid hemorrhage. It is still difficult to predict CA rupture since little is known about the risk factors. Although the mechanism of development, enlargement and rupture of CAs remains unclear, a series of pioneering investigations using animal models of experimentally induced CAs have revealed that hemodynamics are significant in the development of CAs. There have been a number of investigations into the hemodynamics of CAs, which have provided insight into the mechanisms of CA formation. Here, we review experimental and computational work in this field. We first introduce animal models of experimentally induced CAs and studies into the role of hemodynamic stress in the formation of CAs. We also discuss the animal model-based studies on biochemical contributors to CA induction at the cellular and molecular level. We go on to describe hemodynamic studies of CAs using computational fluid dynamics (CFD), including patient-specific CFD models of blood flow, the non-Newtonian viscous nature of blood, and the elastic properties of vessel walls, as well as boundary conditions for CFD simulations. Finally, we review computational studies into risk factors for the development, enlargement and rupture of CAs, and discuss endovascular treatments.