Mechanical thrombectomy failure in anterior circulation strokes: Outcomes and predictors of favorable outcome

Background and purpose Despite continuous improvement and growing knowledge in the endovascular therapy of large vessel occlusion stroke (LVOS), mechanical thrombectomy (MT) still fails to obtain satisfying intracranial recanalization in 10% to 15% of cases. However, little is known regarding clinical and radiological outcomes among this singularly underexplored subpopulation undergoing failed MT. We aimed to investigate the outcome after failed MT and identify predictive factors of favorable outcome despite recanalization failure. Methods We conducted a retrospective analysis of consecutive patients prospectively included in the ongoing observational multicenter Endovascular Treatment in Ischemic Stroke registry from January 2015 to September 2020. Patients presenting with anterior circulation LVOS treated with MT but experiencing failed intracranial recanalization defined as final modified Thrombolysis In Cerebral Infarction (mTICI) score of 0, 1 and 2a were included. Clinical and radiological outcomes were assessed along with the exploration of predictive factors of Day‐90 favorable outcome. Results The study population comprised 533 patients. Mean age was 68.8 ± 16 years, and median admission National Institutes of Health Stroke Scale (NIHSS) and Alberta Stroke Program Early Computed Tomography Score (ASPECTS) were 17 (IQR 12–21) and 7 (IQR 5–8), respectively. Favorable outcomes were observed in 85 patients (18.2%) and 186 died (39.0%). The rate of symptomatic intracranial hemorrhage was 14.1%. In multivariable analysis, younger age (odds ratio [OR] 0.96, 95% CI 0.94–0.98, p