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Fluid-structure interaction of a patient-specific abdominal aortic aneurysm treated with an endovascular stent-graft.
Molony, David S Callanan, Anthony Kavanagh, Eamon G Walsh, Michael T McGloughlin, Tim M
Molony, David S
Callanan, Anthony
Kavanagh, Eamon G
Walsh, Michael T
McGloughlin, Tim M
Advisors
Editors
Other Contributors
Date
2009
Date Submitted
Keywords
Other Subjects
Subject Mesh
Aged
Aortic Aneurysm, Abdominal
Biomechanics
Biomedical Engineering
Blood Vessel Prosthesis
Blood Vessel Prosthesis Implantation
Elastic Modulus
Humans
Male
Models, Anatomic
Models, Theoretical
Pressure
Stents
Stress, Mechanical
Tomography, X-Ray Computed
Aortic Aneurysm, Abdominal
Biomechanics
Biomedical Engineering
Blood Vessel Prosthesis
Blood Vessel Prosthesis Implantation
Elastic Modulus
Humans
Male
Models, Anatomic
Models, Theoretical
Pressure
Stents
Stress, Mechanical
Tomography, X-Ray Computed
Planned Date
Start Date
Collaborators
Principal Investigators
Files
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19807909.pdf
Adobe PDF, 869.01 KB
Alternative Titles
Publisher
Abstract
BACKGROUND: Abdominal aortic aneurysms (AAA) are local dilatations of the infrarenal aorta. If left untreated they may rupture and lead to death. One form of treatment is the minimally invasive insertion of a stent-graft into the aneurysm. Despite this effective treatment aneurysms may occasionally continue to expand and this may eventually result in post-operative rupture of the aneurysm. Fluid-structure interaction (FSI) is a particularly useful tool for investigating aneurysm biomechanics as both the wall stresses and fluid forces can be examined. METHODS: Pre-op, Post-op and Follow-up models were reconstructed from CT scans of a single patient and FSI simulations were performed on each model. The FSI approach involved coupling Abaqus and Fluent via a third-party software - MpCCI. Aneurysm wall stress and compliance were investigated as well as the drag force acting on the stent-graft. RESULTS: Aneurysm wall stress was reduced from 0.38 MPa before surgery to a value of 0.03 MPa after insertion of the stent-graft. Higher stresses were seen in the aneurysm neck and iliac legs post-operatively. The compliance of the aneurysm was also reduced post-operatively. The peak Post-op axial drag force was found to be 4.85 N. This increased to 6.37 N in the Follow-up model. CONCLUSION: In a patient-specific case peak aneurysm wall stress was reduced by 92%. Such a reduction in aneurysm wall stress may lead to shrinkage of the aneurysm over time. Hence, post-operative stress patterns may help in determining the likelihood of aneurysm shrinkage post EVAR. Post-operative remodelling of the aneurysm may lead to increased drag forces.
Language
en
ISSN
1475-925X
eISSN
ISBN
DOI
10.1186/1475-925X-8-24
PMID
19807909