Competitive blood flow from the contralateral vertebral artery signifies a favorable outcome after successful recanalization for acute posterior circulation ischemic stroke.

Abstract

Early prognosis prediction is challenging after endovascular treatment (EVT) for acute posterior circulation ischemic stroke (PCIS). We evaluated the frequency and prognostic impact of competitive blood flow from the contralateral vertebral artery (CBF-cVA), observed post-recanalization. We retrospectively screened patients with acute PCIS who underwent EVT with successful recanalization. CBF-cVA was defined as the rapid clearing of the basilar artery and posterior cerebral arteries previously opacified by antegrade reperfusion. The good functional outcomes are defined as a score of 0-3 on the modified Rankin scale (mRS) at 90 days. Logistic regression was used to investigate the association of CBF-cVA and good functional outcomes at 90 days. A total of 259 patients (median age, 64 years, 74.9% male) were included. CBF-cVA was observable in 44.0% of patients and more frequently in patients with good status of the non-operated vertebral artery which was categorized as good or bad based on the presence of hypoplasia, occlusion, slow flow, or lack of opacification (14.9% vs. 62.1%; p < 0.001) and better collateral score (median 6 vs. 4; p < 0.001). CBF-cVA was associated with good functional outcomes (adjusted OR [95% CI], 3.410 [1.636, 7.105]; p = 0.001), but not with 90-day mortality and symptomatic intracranial hemorrhage (both p > 0.05). CBF-cVA was associated with better functional outcomes in patients with PCIS who underwent EVT with successful recanalization. The presence of CBF-cVA was related to the status of the non-operated vertebral artery and better collateral flow. Question The prediction of early prognosis continues to pose a significant challenge in the clinical management of patients undergoing thrombectomy for posterior circulation strokes. Findings The presence of competitive blood flow from the contralateral vertebral artery (CBF-cVA) was significantly associated with more favorable 90-day functional outcomes. Clinical relevance CBF-cVA provided a practical, binary imaging assessment after endovascular treatment in patients with acute posterior circulation ischemic stroke. This straightforward tool improved the prediction of favorable clinical outcomes, aiding in guiding treatment strategies after recanalization.