Intracranial aneurysms are local dilations of the arterial wall which have a
very high morbidity rate if they rupture. Although the mechanism initiation, growth, and
rupture of intracranial aneurysms are still unknown yet, it is believed to be closely
related to both biosolid and biofluid mechanics. Therefore, a multi-physical model is
needed to study the pathophysiology of intracranial aneurysms. In this study, we
introduce a numerical model on the development of intracranial aneurysms considering
the interaction between fluid and structure interaction. The blood flow is considered to
be incompressible, Newtonian, and laminar. The vessel wall is considered to be elastic
and isotropic. The coupling between the structural and fluid domain is performed using
a two-way weak coupling method. Three general shapes are adopted in this study,
namely a straight vessel, a curved vessel, and a vessel with bifurcations. They represent
vessel geometries that are most typical to the cerebral vasculature. The numerical model
is a "rule-base" one in a sense that different kinds of rules can be tested. In our study,
we adopt the high wall shear stress hypothesis as a cause for aneurysm initiation and
development. A threshold value is used for the wall shear stress. It is shown that
aneurysm initiation and development can be realized using our numerical model. And
the influence of WSS threshold, the Reynolds number and some other parameters are
also discussed.
Keywords: Intracranial aneurysms, arterial wall, biosolid and biofluid mechanics,
numerical model, fluid and structure interaction, straight vessel, curved vessel,
vessel with bifurcations, cerebral vasculature, wall shear stress, aneurysm
initiation and development, blood flow.