Fluid structure interaction of patient specific abdominal aortic aneurysms: a comparison with solid stress models

Title: Fluid structure interaction of patient specific abdominal aortic aneurysms: a comparison with solid stress models
Authors: Leung, JH
Wright, AR
Cheshire, N
Crane, J
Thom, SA
Hughes, AD
Xu, Y
Item Type: Journal Article
Abstract: Background Abdominal aortic aneurysm (AAA) is a dilatation of the aortic wall, which can rupture, if left untreated. Previous work has shown that, maximum diameter is not a reliable determinant of AAA rupture. However, it is currently the most widely accepted indicator. Wall stress may be a better indicator and promising patient specific results from structural models using static pressure, have been published. Since flow and pressure inside AAA are non-uniform, the dynamic interaction between the pulsatile flow and wall may influence the predicted wall stress. The purpose of the present study was to compare static and dynamic wall stress analysis of patient specific AAAs. Method Patient-specific AAA models were created from CT scans of three patients. Two simulations were performed on each lumen model, fluid structure interaction (FSI) model and static structural (SS) model. The AAA wall was created by dilating the lumen with a uniform 1.5 mm thickness, and was modeled as a non-linear hyperelastic material. Commercial finite element code Adina 8.2 was used for all simulations. The results were compared between the FSI and SS simulations. Results Results are presented for the wall stress patterns, wall shear stress patterns, pressure, and velocity fields within the lumen. It is demonstrated that including fluid flow can change local wall stresses slightly. However, as far as the peak wall stress is concerned, this effect is negligible as the difference between SS and FSI models is less than 1%. Conclusion The results suggest that fully coupled FSI simulation, which requires considerable computational power to run, adds little to rupture risk prediction. This justifies the use of SS models in previous studies.
Issue Date: 19-May-2006
Date of Acceptance: 19-May-2006
URI: http://hdl.handle.net/10044/1/43735
DOI: http://dx.doi.org/10.1186/1475-925X-5-33
ISSN: 1475-925X
Publisher: BioMed Central
Journal / Book Title: Biomedical Engineering Online
Volume: 5
Copyright Statement: © 2006 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Keywords: Science & Technology
Engineering, Biomedical
Aged, 80 and over
Aorta, Abdominal
Aortic Aneurysm, Abdominal
Aortic Rupture
Computer Simulation
Contrast Media
Models, Anatomic
Models, Biological
Models, Theoretical
Stress, Mechanical
Tomography, X-Ray Computed
Biomedical Engineering
0903 Biomedical Engineering
Publication Status: Published
Article Number: ARTN 33
Appears in Collections:Faculty of Engineering
National Heart and Lung Institute
Chemical Engineering
Faculty of Medicine

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