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Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics

An attempt has been made to evaluate the effects of wall shear stress (WSS) on thoracic aortic aneurysm (TAA) using Computational Fluid Dynamics (CFD). Aneurysm is an excessive localized swelling of the arterial wall due to many physiological factors and it may rupture causing shock or sudden death....

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Detalles Bibliográficos
Autores principales: Febina, J., Sikkandar, Mohamed Yacin, Sudharsan, N. M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Hindawi 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6008891/
https://www.ncbi.nlm.nih.gov/pubmed/30008797
http://dx.doi.org/10.1155/2018/7126532
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author Febina, J.
Sikkandar, Mohamed Yacin
Sudharsan, N. M.
author_facet Febina, J.
Sikkandar, Mohamed Yacin
Sudharsan, N. M.
author_sort Febina, J.
collection PubMed
description An attempt has been made to evaluate the effects of wall shear stress (WSS) on thoracic aortic aneurysm (TAA) using Computational Fluid Dynamics (CFD). Aneurysm is an excessive localized swelling of the arterial wall due to many physiological factors and it may rupture causing shock or sudden death. The existing imaging modalities such as MRI and CT assist in the visualization of anomalies in internal organs. However, the expected dynamic behaviour of arterial bulge under stressed condition can only be effectively evaluated through mathematical modelling. In this work, a 3D aneurysm model is reconstructed from the CT scan slices and eventually the model is imported to Star CCM+ (Siemens, USA) for intensive CFD analysis. The domain is discretized using polyhedral mesh with prism layers to capture the weakening boundary more accurately. When there is flow reversal in TAA as seen in the velocity vector plot, there is a chance of cell damage causing clots. This is because of the shear created in the system due to the flow pattern. It is observed from the proposed mathematical modelling that the deteriorating WSS is an indicator for possible rupture and its value oscillates over a cardiac cycle as well as over different stress conditions. In this model, the vortex formation pattern and flow reversals are also captured. The non-Newtonian model, including a pulsatile flow instead of a steady average flow, does not overpredict the WSS (15.29 Pa compared to 16 Pa for the Newtonian model). Although in a cycle the flow behaviour is laminar-turbulent-laminar (LTL), utilizing the non-Newtonian model along with LTL model also overpredicted the WSS with a value of 20.1 Pa. The numerical study presented here provides good insight of TAA using a systematic approach to numerical modelling and analysis.
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spelling pubmed-60088912018-07-15 Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics Febina, J. Sikkandar, Mohamed Yacin Sudharsan, N. M. Comput Math Methods Med Research Article An attempt has been made to evaluate the effects of wall shear stress (WSS) on thoracic aortic aneurysm (TAA) using Computational Fluid Dynamics (CFD). Aneurysm is an excessive localized swelling of the arterial wall due to many physiological factors and it may rupture causing shock or sudden death. The existing imaging modalities such as MRI and CT assist in the visualization of anomalies in internal organs. However, the expected dynamic behaviour of arterial bulge under stressed condition can only be effectively evaluated through mathematical modelling. In this work, a 3D aneurysm model is reconstructed from the CT scan slices and eventually the model is imported to Star CCM+ (Siemens, USA) for intensive CFD analysis. The domain is discretized using polyhedral mesh with prism layers to capture the weakening boundary more accurately. When there is flow reversal in TAA as seen in the velocity vector plot, there is a chance of cell damage causing clots. This is because of the shear created in the system due to the flow pattern. It is observed from the proposed mathematical modelling that the deteriorating WSS is an indicator for possible rupture and its value oscillates over a cardiac cycle as well as over different stress conditions. In this model, the vortex formation pattern and flow reversals are also captured. The non-Newtonian model, including a pulsatile flow instead of a steady average flow, does not overpredict the WSS (15.29 Pa compared to 16 Pa for the Newtonian model). Although in a cycle the flow behaviour is laminar-turbulent-laminar (LTL), utilizing the non-Newtonian model along with LTL model also overpredicted the WSS with a value of 20.1 Pa. The numerical study presented here provides good insight of TAA using a systematic approach to numerical modelling and analysis. Hindawi 2018-06-03 /pmc/articles/PMC6008891/ /pubmed/30008797 http://dx.doi.org/10.1155/2018/7126532 Text en Copyright © 2018 J. Febina et al. https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Febina, J.
Sikkandar, Mohamed Yacin
Sudharsan, N. M.
Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics
title Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics
title_full Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics
title_fullStr Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics
title_full_unstemmed Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics
title_short Wall Shear Stress Estimation of Thoracic Aortic Aneurysm Using Computational Fluid Dynamics
title_sort wall shear stress estimation of thoracic aortic aneurysm using computational fluid dynamics
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6008891/
https://www.ncbi.nlm.nih.gov/pubmed/30008797
http://dx.doi.org/10.1155/2018/7126532
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