A 2D constrained mixture model for arterial adaptations to large changes in flow, pressure and axial stretch

Area of Science:

• Biomedical Engineering
• Computational Biology
• Mechanobiology

Background:

• Soft tissue growth and remodeling (G&R) involve complex, time-regulated mechanisms adapting cells and extracellular matrix.
• Vascular adaptation is crucial for maintaining tissue homeostasis under varying physiological conditions.

Purpose of the Study:

• To present a constrained mixture model for simulating vascular adaptations to perturbations in flow rate, pressure, and axial extension.
• To investigate the role of homeostatic stresses in the production of structural constituents during G&R.

Main Methods:

• Development of a constrained mixture model for simulating G&R in evolving configurations.
• Incorporation of hypotheses regarding vasoregulatory mechanisms and constituent turnover rates.
• Simulation of G&R under altered luminal flow rate, transmural pressure, and axial extension.

Main Results:

• Simulations show G&R occurring in dynamically changing loaded configurations.
• The model illustrates that materials produced under different configurations possess distinct natural states and structural contributions.
• Evolving reference states of individual constituents enables adaptation of blood vessel structure and function.

Conclusions:

• The constrained mixture model effectively describes vascular adaptations to significant physiological perturbations.
• The study highlights the importance of evolving reference states for structural constituents in blood vessel homeostasis.
• This modeling approach provides insights into the mechanisms underlying vascular G&R and stress restoration.