The vertebro-subclavian artery angle modulates hemodynamic mechanisms of atherosclerosis in vertebral artery origin: a combined clinical and computational fluid dynamics study

Objective: By dictating local hemodynamics, vascular geometry played a critical role in atherosclerosis (AS). The objective of this research was to clarify how the vertebro-subclavian artery (VA-SCA) angle affected local blood flow patterns in the pathophysiology of AS at the vertebral artery origin (VAO). Methods: This research integrated clinical retrospective analysis with computational fluid dynamics (CFD) simulation. The clinical component examined 364 VAs and classified them into Plaque/Stenosis-free and Plaque/Stenosis groups based on DSA images. Baseline data and morphological parameters (VAO length, tortuosity, VA-SCA angles, and lateralisation) were analysed and compared between the two groups. For the CFD component, idealised geometric models with variable VA-SCA angles were established, and a comprehensive investigation was conducted to elucidate the effects of angle variations on the medial and lateral walls of the VAO region with respect to time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and hemodynamic flow field characteristics. Furthermore, these hemodynamic trends derived from parametric modelling have been validated by patient-specific data. Results: = 0.011) were independent risk factors for AS at the VAO. CFD simulations indicated that across all angle configurations, the lateral VAO wall consistently showed lower TAWSS and higher OSI than the medial wall, with vortex formation observed in all models. With an increase in the VA-SCA angle, the lateral wall TAWSS initially decreased before increasing again, attaining its minimum at 50°, whereas the OSI displayed an opposite trend, peaking at 70°. Analysis of patient-specific data further confirmed that, as the VA-SCA angle increases, TAWSS initially decreases, then increases. At the same time, OSI shows an initial increase followed by a decline. Conclusion: The VA-SCA angle may influence the pathogenesis of AS at the VAO through hemodynamic factors and could serve as a new imaging biomarker to assess hemodynamics in this context.