Coupled Hemodynamics and Oxygen Diffusion in Abdominal Aortic Aneurysm: A Computational Sensitivity Study

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Medical Physics

Background:

• Abdominal Aortic Aneurysms (AAA) are a major cause of mortality, often asymptomatic until rupture.
• Localized oxygen loss (hypoxia) in the AAA wall is linked to rupture risk.
• Intraluminal thrombus (ILT) is frequently present in AAAs and may contribute to hypoxia.

Purpose of the Study:

• To investigate the key factors influencing oxygen diffusion and hypoxia within AAAs.
• To understand the role of intraluminal thrombus (ILT) in AAA oxygen transport.
• To analyze the relationship between AAA geometry, hemodynamics, and oxygen levels.

Main Methods:

• Development of a 3D computational model of AAA with ILT.
• Numerical simulations of blood flow and oxygen distribution.
• Analysis of oxygen transport in the lumen, ILT, and arterial wall.
• Sensitivity analysis of oxygen flow to various parameters.

Main Results:

• AAA bulge diameter has minimal impact on oxygen flow.
• ILT thickness significantly affects oxygen transport to the AAA wall.
• Oxygen supply from vasa vasorum plays a crucial role in AAA oxygenation.
• Arterial wall oxygen concentration shows low variability with reaction rates.

Conclusions:

• Intraluminal thrombus (ILT) presence significantly hinders oxygen transport from the lumen to the AAA wall.
• ILT size and anatomy are important considerations for AAA severity assessment.
• Other parameters beyond ILT also influence thrombus-mediated oxygen delivery in AAAs.