Subacute recanalization and reocclusion in patients with acute ischemic stroke following endovascular treatment

Objective: To determine the rate of subacute recanalization and reocclusion and its effect on clinical outcomes among patients with ischemic stroke treated with endovascular treatment. Subacute recanalization and reocclusion occurring hours after completion of the intravenous or intra-arterial thrombolysis for acute ischemic stroke has been reported in anecdotal cases. Methods: We performed cerebral angiography at 24 h to determine the status of occlusion after endovascular treatment (compared with immediate post-procedure angiogram) in a series of patients with ischemic stroke treated with endovascular treatment. Clinical and radiological evaluations were performed before and 24 h, and prior to discharge or 1-3 months after treatment. We performed multivariate analysis to evaluate the effect of subacute recanalization on clinical outcome graded using modified Rankin scale (mRS). Favorable outcome was defined by mRS of 0-2. Results: A total of 56 patients (mean age 66 ± 14 years; 22 were men) were analyzed. Subacute recanalization was observed in 16 (29%) patients and consisted of additional recanalization in 8 patients with early recanalization. Subacute recanalization was associated with a trend toward a higher rate of favorable outcome (Wald chi-square 3.3, P = 0.19) after adjusting for other covariates. Subacute recanalization was not associated with either neurological deterioration or symptomatic intracranial hemorrhage. Subacute reocclusion was observed in 5 (9%) patients. Subacute reocclusion was associated with a trend toward higher rate of neurological deterioration within 24 h (Wald chi-square 2.1, P = 0.15) after adjusting for other covariates. Conclusion: We found that new or additional recanalization occurs in one-fourth of the patients within 24 h of endovascular treatment and is not associated with any adverse consequences. Subacute reocclusion occurs infrequently after endovascular treatment.