Normal basilar artery structure and biaxial mechanical behaviour

Area of Science:

• Biomedical Engineering
• Vascular Biology
• Biomechanics

Background:

• Cerebral vasospasm following ruptured intracranial aneurysms is a severe complication with unclear mechanisms and limited treatment options.
• Understanding the mechanical properties and structure of healthy cerebral arteries is essential for elucidating vasospasm pathogenesis.

Purpose of the Study:

• To investigate the structure and mechanical behavior of normal rabbit basilar arteries.
• To develop a constitutive model for predicting arterial mechanical responses based on collagen fiber distribution.

Main Methods:

• Mechanical testing of basilar artery segments under biaxial loading with and without active tone.
• Intravital nonlinear optical microscopy to quantify transmural collagen fibril orientations.
• Fitting passive mechanical data to a four-fiber family stress-stretch constitutive model.

Main Results:

• The developed constitutive model accurately predicted the overall mechanical behavior of the basilar arteries.
• The model successfully correlated mechanical data with mean collagen fiber distributions across the arterial wall.

Conclusions:

• The constitutive model provides a promising tool for analyzing the biochemomechanics of cerebral vasospasm.
• Future research should focus on mathematical models incorporating growth and remodeling of collagen to understand vasospasm mechanisms.