Thrombectomy is currently approved for use up to 6 hours after symptom onset; the researchers from the Endovascular Therapy Following Imaging Evaluation for the Ischemic Stroke (DEFUSE 3) trial discovered that even 16 hours after symptom onset, the procedure could improve outcomes compared with those of standard medical therapy.
Using automated software to analyze perfusion magnetic resonance imaging or computer tomography scans, the researchers identified patients thought to have salvageable tissue. The patients were randomly assigned to receive endovascular thrombectomy plus standard medical therapy or medical therapy alone.
In the thrombectomy group, 45% of patients achieved functional independence compared with 17% of the control group. Thrombectomy also was associated with improved survival: 14% of the treated group died within 90 days of the study compared with 26% of the control group.
The DEFUSE 3 trial is a large study supported by StrokeNet, a network of hospitals providing research infrastructure for multisite clinical trials, in this case, at 38 centers. The study was ended early because of “overwhelming” evidence of benefit from the clot removal procedure.
“These striking results will have an immediate impact and save people from lifelong disability or death,” said Walter Korshetz, MD, director of the National Institute of Neurological Disorders and Stroke. “I really cannot overstate the size of this effect.” He adds that 1 of 3 stroke patients with at-risk brain tissue improves, and some may walk out of the hospital “saved from what would otherwise have been a devastating brain injury.”