Hemodynamic Parameters and Early Intimal Thickening in Branching Blood Vessels

Area of Science:

• Cardiovascular Science
• Biomedical Engineering
• Fluid Dynamics

Background:

• Intimal thickening in blood vessels contributes significantly to heart disease.
• Current treatments for occluded vessels include angioplasty, bypass surgery, and endarterectomy.
• Disturbed blood flow patterns are implicated in the development and progression of atherosclerosis and intimal hyperplasia.

Purpose of the Study:

• To analyze hemodynamic wall parameters that indicate sites susceptible to intimal thickening.
• To interpret clinical and experimental observations of intimal thickening using these parameters.
• To explore vessel redesign strategies for improved long-term patency.

Main Methods:

• Analysis of internal branching blood vessel geometries using hemodynamic parameters.
• Comparison of time-averaged wall shear stress (WSS), WSS gradient (WSSG), oscillatory shear index (OSI), and WSS angle gradient (WSSAG) with experimental data.
• Segmental averaging of OSI, wall particle density (WPD), and WSSAG for carotid artery bifurcations and comparison with clinical data.

Main Results:

• Identification of susceptible sites in branching blood vessels.
• Comparison of hemodynamic parameters with experimental and clinical data for aortoceliac junction and carotid artery bifurcations.
• Demonstration that suggested redesigns can reduce hemodynamic parameters like WSSG, WSSAG, and normal pressure gradient (NPG).

Conclusions:

• Hemodynamic wall parameters serve as indicators for intimal thickening.
• Vessel redesign based on these parameters can reduce the likelihood of restenosis, particularly in critical regions like the toe region of vascular access grafts.