Pulsatile albumin transport in large arteries: a numerical simulation study

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Mass Transport Phenomena

Background:

• Atherosclerosis leads to arterial stenosis, altering blood flow dynamics.
• Albumin transport across the endothelium is crucial for vascular health.
• Understanding solute transport in stenosed arteries is vital for disease progression assessment.

Purpose of the Study:

• To numerically analyze albumin transport in a stenosed artery under steady and pulsatile flow.
• To investigate the influence of flow patterns and geometry on albumin wall flux.
• To evaluate endothelial resistance and concentration boundary layer resistance.

Main Methods:

• Incompressible Navier-Stokes and convection-diffusion equations were solved using the finite element method.
• A shear-dependent permeability model incorporated endothelial resistance.
• Simulations focused on a 75% area reduction stenosis model.

Main Results:

• Albumin wall flux demonstrated significant variation along the stenosed artery.
• Flux was highly dependent on flow regimes and varied considerably during the cardiac cycle.
• Pulsatile flow resulted in up to 30% higher time-averaged flux than steady flow in separated regions.

Conclusions:

• Flow dynamics and vascular geometry critically influence albumin transport in stenosed arteries.
• Pulsatile flow significantly alters albumin flux compared to steady flow, particularly in post-stenotic regions.
• Numerical simulations provide valuable insights into atherosclerotic disease progression and solute transport mechanisms.