Book chapter
The Effect of Uncertainty in Vascular Wall Material Properties on Abdominal Aortic Aneurysm Wall Mechanics
Computational Biomechanics for Medicine, pp 69-86
17 Apr 2014
Abstract
Clinical management of abdominal aortic aneurysms (AAA) can benefit from patient-specific computational biomechanics-based assessment of the disease. Individual variations in shape and aortic material properties are expected to influence the assessment of AAA wall mechanics. While patient-specific geometry can be reproduced using medical images, the accurate individual and regionally varying tissue material property estimation is currently not feasible. This work addresses the relative uncertainties arising from variations in AAA material properties and its effect on the ensuing wall mechanics. Computational simulations were performed with five different isotropic material models based on an ex-vivo AAA wall material characterization and a subject population sample of 28 individuals. Care was taken to exclude the compounding effects of variations in all other geometric and biomechanical factors. To this end, the spatial maxima of the principal stress (σmax), principal strain (εmax), strain-energy density (ψmax), and displacement (δmax) were calculated for the diameter-matched cohort of 28 geometries for each of the five different constitutive materials. This led to 140 quasi-static simulations, the results of which were assessed on the basis of intra-patient (effect of material constants) and inter-patient (effect of individual AAA shape) differences using statistical averages, standard deviations, and Box and Whisker plots. Mean percentage variations for σmax, εmax, ψmax, and δmax for the intra-patient analysis were 1.5, 7.1, 8.0, and 6.1, respectively, whereas for the inter-patient analysis these were 11.1, 4.5, 15.3, and 12.9, respectively. Changes in the material constants of an isotropic constitutive model for the AAA wall have a negligible influence on peak wall stress. Hence, this study endorses the use of population-averaged material properties for the purpose of estimating peak wall stress, strain-energy density, and wall displacement. Conversely, strain is more dependent on the material constant variation than on the differences in AAA shape in a diameter-matched population cohort.
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9 citations in Scopus
Details
- Title
- The Effect of Uncertainty in Vascular Wall Material Properties on Abdominal Aortic Aneurysm Wall Mechanics
- Creators
- Samarth S. Raut - Carnegie Mellon UniversityAnirban Jana - Pittsburgh Supercomputing CenterVictor De Oliveira - The University of Texas at San AntonioSatish C. Muluk - Allegheny General HospitalEnder A. Finol - The University of Texas at San Antonio
- Contributors
- Barry Doyle (Editor)Karol Miller (Editor)Adam Wittek (Editor)Poul M.F. Nielsen (Editor)
- Publication Details
- Computational Biomechanics for Medicine, pp 69-86
- Publisher
- Springer New York; New York, NY
- Number of pages
- 18
- Resource Type
- Book chapter
- Language
- English
- Academic Unit
- Cardiothoracic Surgery
- Scopus ID
- 2-s2.0-84930245769
- Other Identifier
- 991021944604304721