Longitudinal displacement in viscoelastic arteries: a novel fluid-structure interaction computational model, and...

Area of Science:

• Biomechanics
• Computational Fluid Dynamics
• Cardiovascular Mechanics

Background:

• Recent in vivo studies reveal significant longitudinal displacements and viscoelastic properties of the arterial wall during the cardiac cycle.
• Existing computational models are limited, primarily capturing only radial displacements due to thin structure approximations.

Purpose of the Study:

• To present a novel, simple fluid-structure interaction (FSI) model capable of simulating both longitudinal and radial arterial wall displacements.
• To incorporate viscoelastic arterial wall properties into the computational model.
• To validate the model against experimental data for common carotid and stenosed coronary arteries.

Main Methods:

• Development of a stable, partitioned numerical scheme for fluid-structure interaction (FSI) analysis.
• Implementation of a model that accounts for both longitudinal and radial displacements and viscoelasticity.
• Comparison of computational results with published in vivo ultrasound data for carotid and coronary arteries.

Main Results:

• The computational model demonstrated excellent agreement with experimental data for longitudinal displacement.
• Longitudinal displacement in stenotic lesions was found to be highly dependent on the specific geometry of the stenosis.
• A reduction in longitudinal displacement was observed in atherosclerotic arteries compared to healthy arteries, correlating with plaque burden.

Conclusions:

• The developed FSI model provides a robust tool for analyzing complex arterial wall mechanics, including longitudinal displacements.
• Longitudinal displacement is a critical factor in arterial wall mechanics, significantly influenced by stenosis geometry and plaque presence.
• This work represents a foundational step towards understanding the physiological and pathophysiological roles of longitudinal displacement in arterial disease using computational simulations.