Flow diversion within seven days after stroke onset is associated with favorable outcome in anterior circulation stroke

Abstract

Anterior cerebral artery (ACA) flow diversion (FD), defined as ipsilateral mean velocity (MV) of at least 30% greater than the contralateral artery, could be seen an indirect sign of leptomeningeal collateralization in the setting of middle cerebral artery occlusion. The purpose of the study was to evaluate the association between dynamic FD and functional outcome in acute anterior stroke patients with large artery occlusion. Acute middle cerebral artery (MCA) or internal carotid artery (ICA) occlusive stroke patients within 12h were recruited. Transcranial Doppler ultrasound was done at baseline, 24h and 7d after onset and velocities of MCA and ACA were recorded. FD ratio was calculated by dividing the ipsilateral ACA MV by the contralateral ACA MV. FD was determined positive when FD ratio ≥1.3. Outcome was assessed by 90-day modified Rankin’s Scale (mRS). The association between FD at different time points and functional outcome were analyzed. 16 patients (median age of 67 and 75% were male) were recruited. FD ratio showed a trend of decline but did not reach statistical significance (p=0.056). The proportion of FD at baseline (p=0.026), 24h (p=0.001) and 7d (p=0.044) was significantly higher in patients with favorable outcome. Higher FD ratio at baseline (p=0.02) and 24h (p=0.003) were significantly associated with favorable outcome. These results suggested that FD ratio showed a trend of decline after stroke onset. Presence of FD within 7days was associated with favorable functional outcome in acute MCA/ICA occlusive stroke patients.