Blood vessel buckling within soft surrounding tissue generates tortuosity

Area of Science:

• Biomechanics
• Vascular Biology
• Biomedical Engineering

Background:

• Vascular stability under pressure is crucial for arterial function.
• Existing models predict simple buckling (half sine wave), but in vivo vessels show complex tortuosity.
• The role of surrounding tissue in blood vessel buckling is not well understood.

Purpose of the Study:

• To analyze the buckling behavior of blood vessels under lumen pressure with surrounding tissue support.
• To investigate how elastic substrate stiffness affects buckling mode shapes and wavelengths.

Main Methods:

• Modeled blood vessels as elastic cylindrical structures within an elastic substrate.
• Developed buckling equations to determine critical pressure and wavelength.
• Utilized simulation results to validate theoretical predictions.

Main Results:

• Blood vessels exhibit higher-order buckling modes when confined within an elastic substrate.
• Without a substrate, vessels buckle into a basal mode shape.
• Increased substrate stiffness leads to a higher wave number (more complex buckling patterns).

Conclusions:

• Mechanical buckling within a supportive elastic substrate is a plausible mechanism for the development of tortuous blood vessels.
• The findings suggest that tissue interaction significantly influences vascular morphology.
• The developed model serves as a valuable tool for future research on arterial and venous tortuosity.