Fluid Structure Interaction Analysis in Abdominal Aortic Aneurysms: Influence of Diameter, Length, and Distal Neck

Giuma, S. K. Badreddin; Osman, Kahar; Kadir, Mohammed Rafiq Abdul

doi:10.1166/jmihi.2013.1201

Cited by 2 publications

(2 citation statements)

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“…Currently, AAA intervention approaches include open surgery, endovascular aneurysm repair and endovascular aneurysm sealing and are based on the diameter size of the aneurysm sac with a follow up routines [11][12][13][14][15]. However, the aneurysm diameter is still a poor indicator of rupture since some reported aneurysms with larger diameter remain intact, while aneurysms of a smaller size have been reported to rupture [5,10,16]. Thus, AAA rupture is ranked as the 13 th leading cause of mortality in the US alone with approximately 15,000 patients every year, and reports of more than 8,000 cases of death in the UK [7,17].…”

Section: Introductionmentioning

confidence: 99%

Computational study on hemodynamic changes in patient-specific proximal neck angulation of abdominal aortic aneurysm with time-varying velocity

Algabri

Rookkapan

Gramigna

et al. 2019

Australas Phys Eng Sci Med

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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.

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Section: Introductionmentioning

confidence: 99%

Computational study on hemodynamic changes in patient-specific proximal neck angulation of abdominal aortic aneurysm with time-varying velocity

Algabri

Rookkapan

Gramigna

et al. 2019

Australas Phys Eng Sci Med

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“…FSI simulations, in which a fully coupled dynamic interaction between the AAA hemodynamics and wall deformations is modeled, were conducted by our group 31, 32 and others to simulate the biomechanical behavior of the AAA wall 10, 29, 33-40 . Most previous FSI studies were based on isotropic material models that exclude the directional response of abdominal aortic tissue to stresses.…”

Section: Introductionmentioning

confidence: 99%

Progression of Abdominal Aortic Aneurysm Towards Rupture: Refining Clinical Risk Assessment Using a Fully Coupled Fluid–Structure Interaction Method

et al. 2014

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Rupture of abdominal aortic aneurysm (AAA) is associated with high mortality rates. Risk of rupture is multi-factorial involving AAA geometric configuration, vessel tortuosity, and the presence of intraluminal pathology. Fluid structure interaction (FSI) simulations were conducted in Patient based computed tomography (CT) scans reconstructed geometries in order to monitor aneurysmal disease progression from normal aortas to non-ruptured and contained ruptured AAA (rAAA), and the AAA risk of rupture was assessed. Three groups of 8 subjects each were studied: 8 normal and 16 pathological (8 non-ruptured and 8 ruptured AAA). The AAA anatomical structures segmented included the blood lumen, intraluminal thrombus (ILT), vessel wall, and embedded calcifications. The vessel wall was described with anisotropic material model that was matched to experimental measurements of AAA tissue specimens. A statistical model for estimating the local wall strength distribution was employed to generate a map of a rupture potential index (RPI), representing the ratio between the local stress and local strength distribution. The FSI simulations followed a clear trend of increasing wall stresses from normal to pathological cases. The maximal stresses were observed in the areas where the ILT was not present, indicating a potential protective effect of the ILT. Statistically significant differences was observed between the peak systolic stress (PSS) and the peak stress at the mean arterial pressure (MAP) between the three groups. For the ruptured aneurysms, where the geometry of intact aneurysm was reconstructed, results of the FSI simulations clearly depicted maximum wall stress at the a-priori known location of rupture. The RPI mapping indicated several distinct regions of high RPI coinciding with the actual location of rupture. The FSI methodology demonstrates that the aneurysmal disease can be described by numerical simulations, as indicated by a clear trend of increasing aortic wall stresses in the studied groups, (normal aortas, AAAs and ruptured AAAs). Ultimately, the results demonstrate that FSI wall stress mapping and RPI can be used as a tool for predicting the potential rupture of an AAA by predicting the actual rupture location, complementing current clinical practice by offering a predictive diagnostic tool for deciding whether to intervene surgically or spare the patient from an unnecessary risky operation.

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Fluid Structure Interaction Analysis in Abdominal Aortic Aneurysms: Influence of Diameter, Length, and Distal Neck

Cited by 2 publications

References 0 publications

Computational study on hemodynamic changes in patient-specific proximal neck angulation of abdominal aortic aneurysm with time-varying velocity

Computational study on hemodynamic changes in patient-specific proximal neck angulation of abdominal aortic aneurysm with time-varying velocity

Progression of Abdominal Aortic Aneurysm Towards Rupture: Refining Clinical Risk Assessment Using a Fully Coupled Fluid–Structure Interaction Method

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