Thrombectomy shows gains one year after severe stroke

At the one-year mark, the difference was no longer easy to miss: 23.6% of patients with severe ischemic stroke who received endovascular thrombectomy were functionally independent, compared with 6.8% treated with medical management alone. The results, published in JAMA, come from a multicenter trial involving 47 U.S. stroke centers.

These were not mild strokes. The patients had large-core infarcts, meaning a substantial amount of brain tissue had already been damaged, and they arrived within 24 hours of symptom onset. They were assessed using noncontrast computed tomography, or CT, imaging. Because so much injury had already occurred, these patients were historically considered less likely to benefit from thrombectomy, the procedure used to remove a clot mechanically and restore blood flow.

The early picture had been less encouraging. At 90 days, the original trial did not show a meaningful benefit. By one year, however, patients who underwent thrombectomy were also more likely to walk independently: 35.4% did so, versus 18% in the medical-management group. They reported better quality of life, while one-year mortality remained similar between the groups.

Sameer A. Ansari, professor and chief of Interventional Neuroradiology, said recovery from severe stroke can continue for one to two years, making the standard 90-day checkpoint an incomplete measure of what treatment achieves. The study found continued improvement in the thrombectomy group between 90 days and one year, while outcomes in the medical-management group stayed static or declined. Restored blood flow may also support neuroplasticity, the brain's ability to reorganize after injury, although the researchers say the mechanism and the patients most likely to benefit require further study.

And then, concretely? For families facing a large stroke, the result gives clinicians more grounds to consider rapid thrombectomy even when the initial brain injury looks extensive—and to explain that meaningful recovery may emerge over months rather than weeks. It does not guarantee independence: most patients in the thrombectomy group did not reach it, mortality was similar, and the findings still need to clarify who benefits most. The procedure was tested in a clinical-trial setting, not presented as a universal solution.