Impact of carotid web orientation on long-term thrombus growth risk: A numerical study using fluid-solid interaction

Abstract

Background

Carotid web (CaW) is a rare fibromuscular dysplasia lesion at the carotid bifurcation linked to thromboembolic events in young patients. CaW-induced hemodynamic disturbances contribute to thrombosis, but the impact of CaW morphology on long-term thrombotic risk remains unclear.

Method

This study developed three-dimensional numerical models based on patient-specific carotid artery anatomy with CaW angles of 30°, 60°, and 90° (models A, B, and C). Unlike prior studies assuming rigid walls, this work incorporated vessel wall elasticity and thrombus growth mechanisms. Fluid–structure interaction simulations analyzed wall deformation, stress, and hemodynamic parameters to assess the effects of CaW angles and wall elasticity on thrombus risk.

Results

Simulations showed that larger CaW angles increased maximum wall deformation at the bifurcation and web region by ∼5 % and maximum stress in the web area by >10 %, indicating higher mechanical load at 90° Flow field analysis revealed that larger angles reduced internal carotid artery velocity and generated recirculation zones. Wall shear stress metrics indicated expanded low-shear and high-residence-time regions in model C, suggesting complex flow patterns. Thrombus growth models showed pronounced thrombus formation at 60° and 90°, with rigid wall simulations underestimating thrombus areas by 15.7 %, 44.5 %, and 85.7 % for models A, B, and C, respectively.

Conclusion

Larger CaW angles are associated with increased flow disturbances and elevated thrombus risk. Variations in the web angle influence thrombus distribution, and incorporating vessel wall elasticity into the analysis enhances risk assessment. Clinically, evaluating carotid geometry and wall elasticity can help optimize thrombus risk evaluation and guide intervention strategies.