Abstract TP3: Early Reocclusion After Mechanical Thrombectomy for Acute Stroke Due to Intracranial Atherosclerotic Stenosis-Related Occlusions

Background: In acute ischemic stroke (AIS) patients due to intracranial atherosclerosis-related occlusions (ICAS-O), despite successful reperfusion with mechanical thrombectomy (MT), unexpected early reocclusion sometimes occurs and worsens clinical outcome. We investigated prevalence, outcomes, and predictors of early reocclusion within 48 hours of MT in AIS due to ICAS-O. Methods: In 557 consecutive AIS patients who underwent MT from January, 2016 to March, 2019 in two stroke centers, 71 patients due to ICAS-O were retrospectively evaluated. We divided them into two groups: patients with early reocclusion and those without. Clinical and angiographical findings and outcomes were compared between the 2 groups. Multivariable logistic regression analysis was used to investigate predictors of early reocclusion after MT. Results: Of 71 patients (aged 72 ± 10 years; 23 women; median NIHSS score, 15), early reocclusion was observed in 11 (15%). The first procedure for recanalization was stent retriever in 25 patients (35%), Penumbra system in 25 patients (35%), and balloon angioplasty in 21 patients (30%). Of these, 63 patients (88%) received rescue therapy (balloon angioplasty, 50; intracranial stenting, 13). In the early reocclusion group, more number of intraprocedural reocclusion (median [IQR], 3 [2-3] vs. 1 [0-1], p < 0.001), a higher rate of remaining stenosis on the final angiography (67.6 ± 5.9% vs 57.3 ± 15.9%, p = 0.044), and a higher rate of procedure-related adverse events (27% vs 5%, p = 0.043) were observed compared to the other group. On logistic regression analysis, a total number of intraprocedural reocclusion was independently associated with early reocclusion (odds ratio, 31.4; 95% confidence interval, 2.6-375.2). Early reocclusion was related to a low rate of favorable outcome at 90 days (modified Rankin Scale ≤ 2, 9% vs 54%, p = 0.007). Conclusions: In AIS patients due to ICAS-O, early reocclusion within 48 hours was not rare and associated with unfavorable outcome. Patients with repeated intraprocedural reocclusion are at high risk for early reocclusion; they might need follow-up angiographical assessment and intensive antithrombotic treatment.