Presenter Information
Tanja Cupac1, Rana Zakerzadeh1
1 Department of Engineering
Duquesne University
Pittsburgh, PA, USA
Abstract
The abdominal aortic aneurysm (AAA) mostly affects men between the ages 65-85 and is very common with more than 3 million cases in the United States per year. AAA is defined as the weakening of the arterial wall producing a blood-filled bulge in the body’s largest blood vessel. AAA is progressive, asymptomatic, and can eventually lead to rupture which is a catastrophic event leading to massive internal bleeding and possibly death. Of the males within this age range, 1-3% will die from this disease. About 75% of AAA cases will be characterized by the development of an intraluminal thrombus (ILT). The ILT correlates with the progression of hypoxia in the arterial wall. Some previous numerical studies have shown the effect of ILT on oxygen diffusion. However, the extent that ILT presence reduces oxygen flux to the wall has not been quantified and there is rather a poor understanding of key parameters that can affect thrombus-mediated mass transport in AAA. The purpose of this study is to address this gap and to assess the effects of different AAA geometric and physical features on the oxygen flow. We develop a modeling approach to investigate the association of ILT in AAA with local hypoxia. We extended our model to account for fluid dynamics in the lumen and oxygen transport in the lumen, thrombus and arterial wall. A sensitivity study was then performed to project oxygen fluctuations dependent on ILT diffusivity, AAA geometric features, and the effect of the vasa vasorum. We observed that the presence of an ILT significantly impairs oxygen transport from the lumen to the wall. We also analyzed the results of a parametric study to investigate how physiologically meaningful variations in model parameters affect oxygen transport within an AAA.
School
Rangos School of Health Sciences
Advisor
Rana Zakerzadeh
Submission Type
Poster
Included in
Multiphysics Computational Model of Fluid Flow and Mass Transfer in Aneurysm
The abdominal aortic aneurysm (AAA) mostly affects men between the ages 65-85 and is very common with more than 3 million cases in the United States per year. AAA is defined as the weakening of the arterial wall producing a blood-filled bulge in the body’s largest blood vessel. AAA is progressive, asymptomatic, and can eventually lead to rupture which is a catastrophic event leading to massive internal bleeding and possibly death. Of the males within this age range, 1-3% will die from this disease. About 75% of AAA cases will be characterized by the development of an intraluminal thrombus (ILT). The ILT correlates with the progression of hypoxia in the arterial wall. Some previous numerical studies have shown the effect of ILT on oxygen diffusion. However, the extent that ILT presence reduces oxygen flux to the wall has not been quantified and there is rather a poor understanding of key parameters that can affect thrombus-mediated mass transport in AAA. The purpose of this study is to address this gap and to assess the effects of different AAA geometric and physical features on the oxygen flow. We develop a modeling approach to investigate the association of ILT in AAA with local hypoxia. We extended our model to account for fluid dynamics in the lumen and oxygen transport in the lumen, thrombus and arterial wall. A sensitivity study was then performed to project oxygen fluctuations dependent on ILT diffusivity, AAA geometric features, and the effect of the vasa vasorum. We observed that the presence of an ILT significantly impairs oxygen transport from the lumen to the wall. We also analyzed the results of a parametric study to investigate how physiologically meaningful variations in model parameters affect oxygen transport within an AAA.