Unfavorable clinical outcomes in patients with good collateral scores following endovascular treatment for acute ischemic stroke of the anterior circulation: The UNCLOSE study.

Despite good collaterals, defined through the American Society for Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale, poor outcomes occurred in almost half of the patients. Patients with good collaterals not receiving intravenous thrombolysis were significantly associated with unfavorable outcomes, whereas first pass effect was not significantly correlated with clinical outcome in this specific cohort of patients. Different methods to assess collaterals should also be investigated.