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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/10854
Title: A structural finite element model for lamellar unit of aortic media indicates heterogeneous stress field after collagen recruitment
Authors: Thunes J.R.
Pal, Siladitya
Fortunato R.N.
Phillippi J.A.
Gleason T.G.
Vorp D.A.
Maiti S.
Published in: Journal of Biomechanics
Abstract: Incorporation of collagen structural information into the study of biomechanical behavior of ascending thoracic aortic (ATA) wall tissue should provide better insight into the pathophysiology of ATA. Structurally motivated constitutive models that include fiber dispersion and recruitment can successfully capture overall mechanical response of the arterial wall tissue. However, these models cannot examine local microarchitectural features of the collagen network, such as the effect of fiber disruptions and interaction between fibrous and non-fibrous components, which may influence emergent biomechanical properties of the tissue. Motivated by this need, we developed a finite element based three-dimensional structural model of the lamellar units of the ATA media that directly incorporates the collagen fiber microarchitecture. The fiber architecture was computer generated utilizing network features, namely fiber orientation distribution, intersection density and areal concentration, obtained from image analysis of multiphoton microscopy images taken from human aneurysmal ascending thoracic aortic media specimens with bicuspid aortic valve (BAV) phenotype. Our model reproduces the typical J-shaped constitutive response of the aortic wall tissue. We found that the stress state in the non-fibrous matrix was homogeneous until the collagen fibers were recruited, but became highly heterogeneous after that event. The degree of heterogeneity was dependent upon local network architecture with high stresses observed near disrupted fibers. The magnitude of non-fibrous matrix stress at higher stretch levels was negatively correlated with local fiber density. The localized stress concentrations, elucidated by this model, may be a factor in the degenerative changes in aneurysmal ATA tissue. © 2016 Elsevier Ltd.
Citation: Journal of Biomechanics (2016), 49(9): 1562-1569
URI: https://doi.org/10.1016/j.jbiomech.2016.03.034
http://repository.iitr.ac.in/handle/123456789/10854
Issue Date: 2016
Publisher: Elsevier Ltd
ISSN: 219290
Author Scopus IDs: 56050124700
35321222100
57188926714
22235590100
7007069675
7005301469
7202014965
Author Affiliations: Thunes, J.R., Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
Pal, S., Mechanical and Industrial Engineering Department, Indian Institute of Technology Roorkee, Roorkee, India
Fortunato, R.N., Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
Phillippi, J.A., Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, PA, United States, Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States, Center for Vascular Remodeling and Regeneration, University of Pittsburgh, Pittsburgh, PA, United States, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
Gleason, T.G., Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, PA, United States, Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States, Center for Vascular Remodeling and Regeneration, University of Pittsburgh, Pittsburgh, PA, United States, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
Vorp, D.A., Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, PA, United States, Department of Surgery, University of Pittsburgh, Pittsburgh, PA, United States, Center for Vascular Remodeling and Regeneration, University of Pittsburgh, Pittsburgh, PA, United States, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
Maiti, S., Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
Funding Details: Research reported in this publication was supported in part by the National Heart, Lung and Blood Institute of the National Institutes of Health under Award Number R01HL109132 (TGG), the National Science Foundation under Award Number CBET 1511504 (JRT and SM)​​, and an NPSC fellowship (JRT). Appendix A
Corresponding Author: Maiti, S.; Department of Bioengineering, University of PittsburghUnited States; email: spm54@pitt.edu
Appears in Collections:Journal Publications [ME]

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