Thrombectomy for proximal intracranial occlusion beyond 24 hours after time last seen normal: A narrative review

Endovascular thrombectomy (EVT) revolutionized the treatment for acute ischemic stroke due to large vessel occlusion (LVO). Current guidelines published by multiple academic societies recommend EVT for eligible patients who present within 24 hours of the time last seen well. However, more recent data suggests that extending this window past 24 hours produces more favorable outcomes in specific patients presenting with anterior circulation LVO. More specifically, recent observational data indicates a higher probability of functional independence, functional improvement, and long-term survival with EVT when compared to best medical management. Based on the available data, there is unclear equipoise in randomizing all patients with acute ischemic stroke due to LVO to EVT or medical management. However, for those patients with large established infarction, distal occlusions, or well beyond the 24-hour window, randomized clinical trials are called upon to determine whether there is benefit of EVT in these patient groups. In this narrative review, we will summarize the most recent data on EVT in the ultra extended window (>24 hours after time last seen normal) and discuss further considerations of this treatment.