BACKGROUND: The benefit of endovascular thrombectomy (EVT) beyond 24 hours from last known well in acute ischemic stroke remains uncertain. Although some slow progressors may retain salvageable tissue, supporting evidence in this ultra-late window comes mainly from small observational studies. METHODS: We systematically searched PubMed, Embase, Scopus, Web of Science, and Cochrane Central up to February 2025 for studies comparing EVT and best medical therapy in patients with acute ischemic stroke treated >24 hours from last known well. Eligible studies reported functional independence (90-day 0–2 modified Rankin Scale score), excellent clinical outcome (90-day 0–1 modified Rankin Scale score), symptomatic intracranial hemorrhage, or 90-day mortality. Pooled unadjusted and adjusted odds ratios (ORs) with 95% CIs were calculated using random-effects meta-analyses. Subgroup analyses were performed by study design, stroke severity, imaging modality, and occlusion territory. Statistical heterogeneity was assessed using the I² statistic and the Cochran Q test, and the certainty of evidence (CoE) was assessed using the Grading of Recommendation, Assessment, Development, and Evaluation approach. RESULTS: Ten observational studies (3 prospective and 7 retrospective) comprising 1871 patients (EVT: 866; best medical therapy: 1009) were included. EVT was associated with significantly higher odds of functional independence (8 studies; adjusted OR, 4.62 95% CI, 3.30–6.47; I ²=0%; low CoE) and excellent clinical outcome (2 studies; adjusted OR, 5.68 95% CI, 2.49–12.97; I ²=0%; very-low CoE). EVT increased the risk of symptomatic intracranial hemorrhage (4 studies; adjusted OR, 9.54 95% CI, 3.78–21.07; I ²=0%; low CoE), but 90-day mortality did not differ significantly between groups (4 studies; adjusted OR, 0.63 95% CI, 0.30–1.31; I ²=41.2%; very-low CoE). All subgroup analyses aligned with the main findings. CONCLUSIONS: Our results revealed that EVT was associated with improved functional outcomes without an increase in 90-day mortality, despite a higher symptomatic intracranial hemorrhage risk. Given the limited CoE and overall study quality, ongoing randomized trials are essential to confirm these findings and guide patient selection in the ultra-late time window.
Rodríguez-Calienes et al. (Fri,) studied this question.