Computational study on hemodynamic changes in patient-specific proximal neck angulation of abdominal aortic aneurysm with time-varying velocity
Aneurysms are considered as a critical cardiovascular disease worldwide when they rupture. The clinical understanding of geometrical impact on the flow behaviour and biomechanics of abdominal aortic aneurysm (AAA) is progressively developing. Proximal neck angulations of AAAs are believed to influence the hemodynamic changes and wall shear stress (WSS) within AAAs. Our aim was to perform pulsatile simulations using computational fluid dynamics (CFD) for patient-specific geometry to investigate the influence of severe angular (≥ 60°) neck on AAA’s hemodynamic and wall shear stress. The patient’s geometrical characteristics were obtained from a computed tomography images database of AAA patients. The AAA geometry was reconstructed using Mimics software. In computational method, blood was assumed Newtonian fluid and an inlet varying velocity waveform in a cardiac cycle was assigned. The CFD study was performed with ANSYS software. The results of flow behaviours indicated that the blood flow through severe bending of angular neck leads to high turbulence and asymmetry of flows within the aneurysm sac resulting in blood recirculation. The high wall shear stress (WSS) occurred near the AAA neck and on surface of aneurysm sac. This study explained and showed flow behaviours and WSS progression within high angular neck AAA and risk prediction of abdominal aorta rupture. We expect that the visualization of blood flow and hemodynamic changes resulted from CFD simulation could be as an extra tool to assist clinicians during a decision making when estimation the risks of interventional procedures.
KeywordsAbdominal aortic aneurysm Angulated neck Computational fluid dynamics Wall shear stress Hemodynamic Computed tomography
Abdominal aortic aneurysms
Computational fluid dynamics
Digital imaging and communications in medicine
Endovascular aortic aneurysm repair
Region of interest
Wall shear stress
The authors wish to thank Mr. Sumrit Ruangchan and the radiology department, faculty of medicine, Prince of Songkla University for assisting with and providing the patient CT images, data and clinical suggestions.
This study was funded by the Thailand’s Education Hub for Southern Region of ASEAN Countries (TEH-AC) scholarship given to the Mr. Yousif A. Algabri and the thesis support funding from the graduate school, Prince of Songkla University. This work was also supported by a Researcher Links grant, ID 2017-RLTG8-10538, under the Newton-TRF Fund partnership. The grant is funded by the UK Department for Business, Energy and Industrial Strategy and Thailand Research Fund (TRF) (PDG61W0013) and delivered by the British Council.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors. Only images from patient-specific data were used in this study under the ethical approval acquired from Faculty of Medicine Ethics Committee, Prince of Songkla University under number REC.61-010-25-2.
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