Patients with severe strokes had better one-year outcomes after thrombectomy than with medical management alone, follow-up data suggest.
The analysis involved patients with ischaemic stroke and large-core infarcts, meaning a significant amount of brain tissue had already been damaged.
Sameer A. Ansari, professor and chief of interventional neuroradiology in the Department of Radiology and a co-author of the study, said these patients have historically been considered less likely to benefit from mechanical clot removal because of the extent of brain damage by the time treatment begins.
While the original trial did not show a meaningful benefit at 90 days, the one-year follow-up found functional gains among patients who underwent endovascular thrombectomy.
Ansari said the results suggest longer-term follow-up was needed to fully understand the benefits of the procedure.
“At one year, it’s quite evident based on the statistical analysis that there’s significant benefit with thrombectomy,” said Ansari, also a professor in the Ken and Ruth Davee Department of Neurology and of Neurological Surgery.
Researchers found that 23.6 per cent of patients treated with endovascular thrombectomy achieved functional independence one year after their stroke, compared with 6.8 per cent of those who received medical management.
Patients who underwent thrombectomy were also significantly more likely to regain the ability to walk independently. This was achieved by 35.4 per cent of the thrombectomy group, compared with 18 per cent of the medical-management group.
The multicentre trial enrolled patients at 47 US stroke centres who presented within 24 hours of symptom onset and had large strokes identified using noncontrast computed tomography, or CT, imaging.
Patients treated with thrombectomy also reported better quality of life one year after stroke. Mortality rates at one year were similar between the groups.
The findings add to evidence from other large-core interventional stroke trials suggesting that patients with extensive brain injury can still benefit from rapid thrombectomy to restore blood flow.
Ansari said one possible explanation for the delayed benefit is that recovery from severe stroke can continue beyond the 90-day assessment period used in most clinical trials.
“We know that people continue to improve after a stroke for the next one to two years,” Ansari said.
“Three months has been an arbitrary standard used in prior stroke trials to assess benefit and functional outcomes after targeted interventions.”
Restoring blood flow may also support long-term neuroplasticity, the brain’s ability to reorganise and form new neural connections after injury, Ansari said.
The study found that patients who received thrombectomy continued to improve between 90 days and one year, while outcomes remained static or declined in the medical-management group.
Further research is needed to determine which patients with large-core strokes are most likely to benefit from thrombectomy.
The results may provide additional confidence that aggressive intervention can yield meaningful recovery, even when improvement is not immediately apparent.
“What we’re seeing across multiple randomized controlled trials, endovascular thrombectomy remains a powerful intervention across a spectrum of stroke presentations,” Ansari said.
“It gives clinicians more confidence to treat patients even with severe brain injury and to counsel their loved ones that the outcome benefit may require time to heal, hard work with physical therapy/rehabilitation, and family support.”
