Biomechanics and Modeling in Mechanobiology

, Volume 10, Issue 1, pp 109–132 | Cite as

Modelling evolution and the evolving mechanical environment of saccular cerebral aneurysms

  • P. N. WattonEmail author
  • A. Selimovic
  • N. B. Raberger
  • P. Huang
  • G. A. Holzapfel
  • Y. Ventikos
Original Paper


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.


Aneurysm Finite elasticity Cerebral Growth Remodelling Haemodynamics Cyclic stretch WSS WSSG OSI RRT 


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • P. N. Watton
    • 1
    Email author
  • A. Selimovic
    • 1
  • N. B. Raberger
    • 2
  • P. Huang
    • 1
  • G. A. Holzapfel
    • 3
    • 4
  • Y. Ventikos
    • 1
  1. 1.Institute of Biomedical Engineering and Department of Engineering ScienceUniversity of OxfordOxfordUK
  2. 2.ETHZurichSwitzerland
  3. 3.Institute of Biomechanics, Center of Biomedical EngineeringGraz University of TechnologyGrazAustria
  4. 4.Department of Solid Mechanics, School of Engineering SciencesRoyal Institute of Technology (KTH)StockholmSweden

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