February 10, 2025Scientific ReportsOpen Access

Hemodynamic effects of stenosis with varying severity in different segments of the carotid artery using computational fluid dynamics

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Why the study?

Carotid atherosclerosis narrows the lumen and alters hemodynamics, which can contribute to subsequent lesions, but the effects of varying stenosis severity across different segments require clarification.

How do varying degrees and locations of carotid artery stenosis affect hemodynamic parameters such as wall shear stress, oscillatory shear index, and relative residence time in computational models?

Structured PICO

How do varying degrees and locations of carotid artery stenosis affect hemodynamic parameters such as wall shear stress, oscillatory shear index, and relative residence time in computational models?

Population

54 idealized carotid artery stenosis (CAS) models built from a single healthy carotid artery

Intervention

Simulation of six different degrees of stenosis (10%, 30%, 40%, 60%, 70%, 90%) at nine various locations (proximal, middle, and distal segments of the CCA, ECA, and ICA) using computational fluid dynamics (CFD)

Comparator

Healthy carotid artery model and comparisons across varying degrees and locations of stenosis

Outcome

Hemodynamic indicators: wall shear stress (WSS), oscillatory shear index (OSI), and relative residence time (RRT)surrogate

Computational fluid dynamics modeling demonstrates that increasing carotid stenosis severity elevates wall shear stress at the stenosis site while reducing it at bifurcations, providing insights into regions at high risk for plaque rupture or progression.

Limitations

Relies on idealized, simplified models of stenosis that may not fully capture anatomical and pathological complexities in real patients
Does not reflect irregular, asymmetric stenotic regions caused by patient-specific factors
Modeling stenosis at predefined locations limits the ability to capture the variability of stenosis formation
Adoption of a rigid wall model neglects arterial wall elasticity

Implication

These patterns may flag rupture-prone carotid sites; leaves open translation from animal models to human plaque risk assessment.

Abstract

Carotid atherosclerosis is a leading cause of ischemic stroke. As a result of atherosclerotic plaque formation, the carotid artery lumen narrows, leading to significant hemodynamic alterations. These changes can further contribute to the development of subsequent lesions. In this study, we built 54 idealized carotid artery stenosis (CAS) models by using a single healthy carotid artery to simulate six different degrees of stenosis at nine various locations. Computational fluid dynamics (CFD) was applied to analyze blood flow changes, focusing on three key hemodynamic indicators: wall shear stress (WSS), oscillatory shear index (OSI), and relative residence time (RRT). Numerical simulations and model validations were conducted to ensure the correctness and validity of the results. The results show that increasing stenosis severity leads to higher WSS values at the site of stenosis, which may facilitate plaque rupture, while OSI and RRT decrease at the stenosis site. In the external carotid artery (ECA) and internal carotid artery (ICA), increasing stenosis severity results in a reduction in WSS at bifurcation sites, promoting plaque formation. These findings offer new insights into the hemodynamic changes associated with carotid artery stenosis and provide a solid foundation for future research and clinical applications.