Hematocrit dispersion in asymmetrically bifurcating vascular networks

Area of Science:

• Physiological modeling
• Vascular network analysis
• Microcirculation dynamics

Background:

• Accurate quantitative modeling of physiological processes in vasculatures necessitates precise representation of network topology and vessel branching.
• Understanding red blood cell (RBC) distribution at vessel bifurcations is crucial for microcirculation.

Purpose of the Study:

• To propose a new approach for reconstructing vascular networks that determines red blood cell distribution at bifurcations.
• To incorporate non-Newtonian blood behavior and optimize for physiological cost of oxygen supply.

Main Methods:

• Developed a reconstruction method based on Murray's law and functional optimality.
• Accounted for non-Newtonian blood viscosity varying with discharge hematocrit and vessel radius.
• Defined bifurcation asymmetry by oxygen consumption of supplied tissue volumes.

Main Results:

• The constructed vascular networks exhibit non-uniform wall shear stress and increased pressure gradients in terminal sections.
• Observed non-uniform hematocrit partitioning at bifurcations and across the capillary bed.
• Demonstrated a linear relationship between red blood cell flux fraction and blood flow fraction at bifurcations.

Conclusions:

• The proposed method successfully reconstructs vascular networks that align with observed physiological characteristics.
• The model provides insights into the functional optimality and hematocrit distribution within microcirculation.