Number of passes and outcome of endovascular treatment of anterior circulation large core ischemic stroke: insights from the Endovascular Treatment in Ischemic Stroke (ETIS) registry.

Background: The effect of multiple attempts on the outcome of endovascular treatment (EVT) of anterior circulation large ischemic core (LIC) stroke has not been fully explored.

Methods: We analyzed data from the Endovascular Treatment in Ischemic Stroke (ETIS) registry, a prospective, observational, multicenter study of acute ischemic stroke patients treated with EVT at 21 centers in France between January 1, 2015 and June 31, 2023. We included patients with proximal intracranial occlusion and LIC defined as Alberta Stroke Program Early CT Score (ASPECTS) of 0-5 up to 24 hours after last being seen well. We divided patients according to the number of passes with successful reperfusion (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2b) into seven groups, according to the corresponding number of passes. We compared them to the group of patients with unsuccessful reperfusion.

Results: A total of 1235 patients with LIC constituted the study cohort. The rate of a modified Rankin Scale (mRS) score of 0 to 3 at 90 days was significantly higher for the one-pass successful recanalization category compared to no recanalization (48.1% vs 17.2%; adjusted OR (aOR) 7.99, 95% CI 4.30 to 14.8, P<0.001) and remained so even after six or more attempts (27.7% vs 17.2%; aOR 3.59, 95% CI 1.37 to 9.39, P=0.009). The rate of symptomatic intracranial hemorrhage was lower for successful recanalization up to two passes (11.1% vs 18.8%; aOR 0.36, 95% CI 0.18 to 0.69, P=0.002) without any significant differences for a higher number of passes.

Conclusion: In anterior circulation LIC patients, successful reperfusion, even after six passes, is associated with favorable clinical outcomes with no increased hemorrhagic risk when compared to unsuccessful reperfusion.