A validated 3D microstructure-based constitutive model of coronary artery adventitia

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Materials Science

Background:

• Understanding vascular physiology requires accurate models of blood vessel mechanics.
• Existing models often lack detailed microstructural data for coronary adventitia.
• Coronary adventitia's mechanical behavior is crucial for overall vascular function.

Purpose of the Study:

• To develop and validate a 3D structure-based model of coronary adventitia.
• To incorporate elastin and collagen distributions into the microstructural model.
• To investigate the mechanical role of different adventitial layers and components.

Main Methods:

• Developed a 3D microstructural model based on measured elastin and collagen distributions.
• Assessed the role of ground substance via enzyme degradation of glycosaminoglycans.
• Validated the model against biaxial inflation and extension experiments of coronary adventitia.

Main Results:

• The model accurately predicted nonlinear mechanical responses of coronary adventitia.
• Ground substance was found to be negligible under physiological axial stretch.
• Inner adventitia collagen fibers bear the majority of load at higher pressures.

Conclusions:

• The validated structure-based model provides a deeper understanding of vascular mechanics.
• Accurate fiber distribution measurements are critical for rigorous mechanical analysis.
• The model can be extended to study vascular disease conditions.