Modelling evolution of saccular cerebral aneurysms

Abstract

A computational model for the evolution of a saccular cerebral aneurysm of the internal carotid artery is developed. The artery is modelled as a two-layered non-linear elastic cylindrical membrane using a physiologically realistic constitutive model. It is subject to a constant systolic pressure and a physiological axial prestretch. The development of the aneurysm is assumed to be a consequence of the growth and remodelling of its material constituents. The elastinous constituents are prescribed to degrade in a localized circular patch. Microstructural recruitment and fibre concentration variables for the collagen fibres enable the growth and remodelling of collagen fabric to be simulated. The model predicts realistic saccular aneurysm geometries that stabilize in size. It provides the foundations for the development of more sophisticated models of cerebral aneurysm evolution.