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. Plain Language Summary<br /> This study investigates the relationship between vertebral artery (VA) blood flow and posterior circulation infarctions (PCI), which are strokes in the back of the brain. VAs play a crucial role in supplying blood to this area. Using color duplex ultrasonography, we measured blood flow in 234 patients with severe VA narrowing (>= 70%). These patients were divided into two groups: those who had experienced PCI and those who had not. We analyzed the correlation between blood flow in the VAs and various brain imaging data to understand the occurrence of PCI under different conditions. The findings showed that lower blood flow through the VAs was significantly associated with a higher risk of PCI, particularly in cases involving large artery atherosclerosis (a type of artery disease). However, this association was not observed in cases of branch artery occlusive disease. A detailed analysis revealed that for every 10 mL/min increase in blood flow, the risk of PCI decreased by 11%. This relationship also varied according to the patients' blood glucose levels: patients with lower blood glucose levels showed a stronger link between increased blood flow and reduced PCI risk compared to those with moderate or high blood glucose levels. In conclusion, measuring the blood flow in the VAs can help identify patients at high risk of strokes in the back part of the brain. However, it is important to consider this measurement in combination with blood glucose levels to improve the identification of high-risk patients. (c) 2024 S. Karger AG, Basel