Modelling evolution and the evolving mechanical environment of saccular cerebral aneurysms
2011 (English)In: Biomechanics and Modeling in Mechanobiology, ISSN 1617-7959, E-ISSN 1617-7940, Vol. 10, no 1, 109-132 p.Article in journal (Refereed) Published
A fluid-solid-growth (FSG) model of saccular cerebral aneurysm evolution is developed. It utilises a realistic two-layered structural model of the internal carotid artery and explicitly accounts for the degradation of the elastinous constituents and growth and remodelling (G&R) of the collagen fabric. Aneurysm inception is prescribed: a localised degradation of elastin results in a perturbation in the arterial geometry; the collagen fabric adapts, and the artery achieves a new homeostatic configuration. The perturbation to the geometry creates an altered haemodynamic environment. Subsequent degradation of elastin is explicitly linked to low wall shear stress (WSS) in a confined region of the arterial domain. A sidewall saccular aneurysm develops, the collagen fabric adapts and the aneurysm stabilises in size. A quasi-static analysis is performed to determine the geometry at diastolic pressure. This enables the cyclic stretching of the tissue to be quantified, and we propose a novel index to quantify the degree of biaxial stretching of the tissue. Whilst growth is linked to low WSS from a steady (systolic) flow analysis, a pulsatile flow analysis is performed to compare steady and pulsatile flow parameters during evolution. This model illustrates the evolving mechanical environment for an idealised saccular cerebral aneurysm developing on a cylindrical parent artery and provides the guidance to more sophisticated FSG models of aneurysm evolution which link G&R to the local mechanical stimuli of vascular cells.
Place, publisher, year, edition, pages
2011. Vol. 10, no 1, 109-132 p.
Aneurysm, Finite elasticity, Cerebral, Growth, Remodelling, Haemodynamics, Cyclic stretch, WSS, WSSG, OSI, RRT
IdentifiersURN: urn:nbn:se:kth:diva-30567DOI: 10.1007/s10237-010-0221-yISI: 000286611200008ScopusID: 2-s2.0-79551553780OAI: oai:DiVA.org:kth-30567DiVA: diva2:401011
FunderEU, European Research Council, FP6-2004-IST-4
QC 201103012011-03-012011-02-282012-03-22Bibliographically approved