A new meta-analysis in The Lancet finds that endovascular thrombectomy significantly improves functional outcomes and reduces mortality compared to medical management alone for patients with large-core ischemic stroke treated up to 24 hours after symptom onset. The study, which pooled individual patient data from multiple trials, used central imaging adjudication to ensure consistency. This extends the therapeutic window beyond the standard 6- to 16-hour limits for certain patients.
The findings challenge current guidelines that often restrict thrombectomy to patients with smaller core volumes or earlier treatment windows. Large-core strokes, which involve substantial brain tissue already damaged, have historically been considered poor candidates for intervention due to bleeding risks. The analysis suggests many such patients still benefit from clot removal, potentially changing emergency stroke protocols worldwide.
Benefits were observed across nearly all subgroups defined by the Alberta Stroke Program Early CT Score (ASPECTS) and ischemic core volumes, with one key exception: patients with core volumes of 150 mL or greater who presented more than 6 hours after onset did not show clear improvement. For others, the procedure reduced disability and death regardless of time up to 24 hours, though earlier treatment still correlated with better results.
The results could expand thrombectomy eligibility to thousands more patients annually, particularly in regions with delayed hospital access. Hospitals may need to invest in advanced imaging to identify suitable candidates quickly. The authors urge updated clinical guidelines to reflect these data and call for further research on the excluded subgroup with very large cores beyond 6 hours.
Experts caution that real-world outcomes may vary from trial settings, and patient selection must remain rigorous. The study did not evaluate long-term cognitive effects or quality of life, leaving some questions unanswered.