Hemodynamics of asymmetrically stenotic vertebral arteries based on fluid-solid coupling

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Medical Imaging Analysis

Background:

• Vertebral artery stenosis (VAS) is a critical condition affecting cerebral blood flow.
• Understanding the hemodynamics and biomechanics of stenosis is essential for clinical management.
• Current models require further refinement to capture complex flow-structure interactions.

Purpose of the Study:

• To investigate the mechanical properties and internal dynamics of pulsatile blood flow in the vertebral artery with stenosis.
• To establish a mathematical model for asymmetrical stenosis and analyze its relationship with hemodynamic parameters.
• To evaluate the impact of stenosis geometry on blood flow, vessel wall stress, and potential complications.

Main Methods:

• Development of an asymmetrical stenosis mathematical model.
• Construction of patient-specific stenosis models using medical imaging data.
• Analysis using computational fluid dynamics (CFD) and fluid-structure interaction (FSI) simulations.
• Evaluation of hemodynamic parameters (e.g., velocity, TAWSS) and solid mechanics indicators (e.g., deformation, von Mises stress).

Main Results:

• Stenosis height and length significantly influence resistance and shear stress ratios.
• Whole-segment stenosis can lead to thrombosis and intimal damage.
• Ostial stenosis increases the risk of platelet deposition and atherosclerosis.
• FSI simulations show elastic vessel walls are sensitive to high-velocity flows in stenotic regions.

Conclusions:

• Stenosis geometry critically affects vertebral artery hemodynamics and biomechanics.
• Specific stenosis locations pose distinct risks for vascular complications like thrombosis and atherosclerosis.
• Findings offer vital insights for developing clinical interventions for vertebral artery stenosis.
• Understanding flow-structure interactions is key to mitigating risks of impaired brain blood supply.