Multi-Scale Modelling of Vascular Disease: Abdominal Aortic Aneurysm Evolution - Computational Modeling in Tissue Engineering - page 298

Multi-Scale Modelling of Vascular
Disease: Abdominal Aortic Aneurysm
Evolution

Paul N. Watton, Huifeng Huang and Yiannis Ventikos

Abstract We present a fluid-solid-growth (FSG) computational framework to
simulate the mechanobiology of the arterial wall. The model utilises a realistic
constitutive model that accounts for the structural arrangement of collagen fibres
in the medial and adventitial layers, the natural reference configurations in which
the collagen fibres are recruited to load bearing and the (normalised) mass-density
of the elastinous and collagenous constituents. Growth and remodelling (G&R) of
constituents is explicitly linked to mechanical stimuli: computational fluid
dynamic analysis produces snapshots of the frictional forces acting on the endo-
thelial cells; a quasi-static structural analysis is employed to quantify the cyclic
deformation of the vascular cells. We apply the computational framework to
simulate the evolution of a specific vascular pathology: abdominal aortic aneurysm
(AAA). Two illustrative models of AAA evolution are presented. Firstly, the
degradation of elastin (that is observed to accompany AAA evolution) is pre-
scribed, and secondly, it is linked to low levels of wall shear stress (WSS). In the
first example, we predict the development of tortuosity that accompanies AAA
enlargement, whilst in the latter, we illustrate that linking elastin degradation to
low WSS leads to enlarging fusiform AAAs. We conclude that this computational
framework

provides the basis for further investigating and elucidating the

P. N. Watton ( & ) Y. Ventikos
Department of Engineering Science, Institute of Biomedical Engineering,
University of Oxford, Oxford, UK
e-mail: [e-mail]
Y. Ventikos
e-mail: [e-mail]
H. Huang
Department of Mathematics, Imperial College, London, UK
e-mail: [e-mail]