Abstract 77: Collateral Status And Recanalization After Endovascular Treatment For Acute Ischemic Stroke

Abstract

Background: Successful recanalization and good collateral status are associated with good clinical outcome in patients with acute ischemic stroke treated with endovascular treatment, but the relationships among them are unclear. Methods: We analysed data from the MR CLEAN Registry, a multicenter prospective cohort study of patients with acute ischemic stroke who underwent endovascular treatment in the Netherlands. Collateral status was assessed using a common 4-point visual grading scale. Successful recanalization was defined as an extended Thrombolysis in Cerebral Infarction score ≥ 2B. Functional outcome at 90 days was determined with the modified Rankin Scale score. We assessed, in multivariable (ordinal) logistic regression models, the associations between 1) collateral status and successful recanalization, 2) successful recanalization and functional outcome, 3) collateral status and functional outcome. An interaction term (successful recanalization*collateral grade) was added to the latter model, to assess effect modification. Subgroup analyses were performed for patients treated with intravenous thrombolysis. Results: We included 2717 patients, 1898 (70%) with successful recanalization. There was no relationship between collateral status and successful recanalization. Successful recanalization (acOR 2.15, 95% CI 1.84-2.52) and better collateral grades (Grade 1, acOR 2.12, 95% CI 1.47-3.05; Grade 2, acOR 3.46, 95% CI 2.43-4.92; Grade 3, acOR 4.16, 95% CI 2.89-5.99) were both associated with a shift towards better functional outcome. There was no significant interaction between collateral status and successful recanalization. Results were similar for patients treated with intravenous thrombolysis. Conclusions: Collateral status is not associated with the probability of successful recanalization after endovascular treatment and does not modify the association between successful recanalization and functional outcome.