Structural Features of Microvascular Networks Trigger Blood Flow Oscillations

Area of Science:

• Mathematical modeling
• Fluid dynamics
• Biophysics

Background:

• Vascular networks exhibit complex microstructural features.
• Understanding blood flow dynamics is crucial for biological systems.
• Identifying factors promoting flow instability is an ongoing research area.

Purpose of the Study:

• To analyze mathematical models of vascular networks.
• To understand how microstructural features influence blood flow dynamics.
• To identify characteristics promoting self-sustained oscillations in blood flow.

Main Methods:

• Analysis of a simple three-node vascular network motif.
• Utilized mathematical descriptions for blood rheology and haematocrit splitting.
• Employed numerical simulations and stability analysis.
• Investigated system dynamics and multiple steady-state solutions.

Main Results:

• Network redundancy and differing haemodynamic resistances promote oscillatory dynamics.
• A Hopf bifurcation leads to oscillatory states from non-trivial steady states.
• Oscillations require sufficiently different branch diameters for significant redundant vessel flow.
• A two-parameter stability diagram (branch diameter ratio, inlet haematocrit) delineates oscillatory regimes.

Conclusions:

• Microstructural properties like network redundancy and varied branch resistance can drive blood flow oscillations.
• Sufficiently different branch diameters are key to initiating flow oscillations.
• These findings can help explore sources of flow instability in biological microvascular networks.