Association between Bilateral Vertebral Artery Blood Flow Changes and Posterior Circulation Infarction in Patients with Severe Intracranial Stenosis

Introduction: The objective of this study was to explore the association between net vertebral artery flow volume (NVAFV), calculated through color duplex ultrasonography, and posterior circulation infarction (PCI) in patients with severe intracranial vertebral artery (VA) stenosis. Methods: 234 patients with severe intracranial VA stenosis (≥70%) were categorized into the PCI group (n = 139) and the non-PCI group (n = 95) based on cranial MRI diagnosis. The correlation between NVAFV and CT perfusion data was analyzed, and the occurrence of PCI under diverse PCI mechanisms was also investigated. Multifactorial logistic regression and stratified analysis was performed to analyze the association between NVAFV and PCI. Lastly, generalized additive models and smooth curve fitting was utilized to outline relationship between NVAFV and PCI. Results: NVAFV showed a significant correlation with cerebral blood flow, mean transmit time, and time to peak. In the large artery atherosclerosis mechanism, a reduction in NVAFV correlated with a gradual rise in PCI cases (p = 0.002), while this trend lacked significance in the branch artery occlusive disease mechanism (p = 0.993). In the fully adjusted model, each 10 mL/min increase in NVAFV reduced PCI incidence by 11% (OR 0.890, 95% CI 0.840–0.943, p < 0.001), Sensitivity analysis showed similar results; NVAFV presented different PCI risks among various glucose level subgroups, the OR (95% CI) for PCI was 0.788 (0.684, 0.906) in low-glucose group (T1), 0.968 (0.878, 1.066) in moderate-glucose group (T2), and 0.886 (0.801, 0.979) in high-glucose group (T3). Smooth curve fitting demonstrated a linear negative association between NVAFV and PCI. Conclusion: NVAFV demonstrated an association with PCI in patients with severe intracranial VA stenosis, it can serve as a reference for identifying high-risk populations of PCI; however, it must be considered in combination with glucose.