The Relationship Between Collateral Flow And Outcome After Intravenous Thrombolysis In Acute Ischemic Stroke Patients On Dynamic CTA

Purpose:To evaluate the collateral flow of acute ischemic stroke patients by dynamic CT angiography (CTA), and then to analyze the relationship between collateral flow and severity of ischemia or outcome after intravenous thrombolysis.Methods:We retrospectively analyzed CT perfusion (CTP) imaging of acute ischemic stroke patients with middle cerebral artery (MCA) or internal carotid artery (ICA) occlusion who receiving intravenous thrombolysis, and reconstructed it for dynamic CTA. The total extent and the flow speed of collateral flow based on the dynamic CTA were evaluated. The relationships between collateral flow and radiological variables or neurological outcome after thrombolysis were explored. Results:Compared with the poor collateral flow group, patients with good collateral flow had lower NIHSS within1month after thrombolysis (6.4±5.2vs23.4±14.2, P=0.001).Total condition score of collateral flow had negative correlation with mRS of3month (r=-0.675, P=0.002). Patients with large collateral extent had the tendency of more recanalization and less hemorrhage transformation than those with small collateral extent (63.6%vs25.0%,P=0.061;0%vs31.3%, P=0.06).The score of total collateral condition had negative correlation with baseline and final infarct volume(r=-0.40,P=0.042; r=-0.48, P=0.014).Conclusion:Patients with good collateral flow had a less infarct volume and better outcome after intravenous thrombolysis. Evaluating collateral flow by dynamic CTA may be used to predict clinical outcome.