A thick-walled fluid–solid-growth model of abdominal aortic aneurysm evolution: application to a patient-specific geometry

Grytsan, A., Watton, P. N. and Holzapfel, G. (2015) A thick-walled fluid–solid-growth model of abdominal aortic aneurysm evolution: application to a patient-specific geometry. Journal of Biomechanical Engineering, 137(3), 031008. (doi: 10.1115/1.4029279) (PMID:25473877)

Full text not currently available from Enlighten.

Abstract

We propose a novel thick-walled fluid–solid-growth (FSG) computational framework for modeling vascular disease evolution. The arterial wall is modeled as a thick-walled nonlinearly elastic cylindrical tube consisting of two layers corresponding to the media-intima and adventitia, where each layer is treated as a fiber-reinforced material with the fibers corresponding to the collagenous component. Blood is modeled as a Newtonian fluid with constant density and viscosity; no slip and no-flux conditions are applied at the arterial wall. Disease progression is simulated by growth and remodeling (G&R) of the load bearing constituents of the wall. Adaptions of the natural reference configurations and mass densities of constituents are driven by deviations of mechanical stimuli from homeostatic levels. We apply the novel framework to model abdominal aortic aneurysm (AAA) evolution. Elastin degradation is initially prescribed to create a perturbation to the geometry which results in a local decrease in wall shear stress (WSS). Subsequent degradation of elastin is driven by low WSS and an aneurysm evolves as the elastin degrades and the collagen adapts. The influence of transmural G&R of constituents on the aneurysm development is analyzed. We observe that elastin and collagen strains evolve to be transmurally heterogeneous and this may facilitate the development of tortuosity. This multiphysics framework provides the basis for exploring the influence of transmural metabolic activity on the progression of vascular disease.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Holzapfel, Professor Gerhard and Watton, Dr Paul
Authors: Grytsan, A., Watton, P. N., and Holzapfel, G.
College/School:College of Science and Engineering > School of Mathematics and Statistics > Mathematics
Journal Name:Journal of Biomechanical Engineering
Publisher:American Society of Mechanical Engineers
ISSN:0148-0731
ISSN (Online):1528-8951
Published Online:29 January 2015

University Staff: Request a correction | Enlighten Editors: Update this record