Mechanical clot removal for late-stage stroke patients

Plain-English translation of NCT03502408 on ClinicalTrials.gov ↗ · Source last updated November 2022 · Translation generated July 2026 · How we translate trials

This study doesn't follow the usual testing phases — it may be an observational study or a different type of research.

What is this trial?

This trial is testing whether endovascular thrombectomy—a minimally invasive procedure that removes blood clots from brain blood vessels—can safely help stroke patients who arrive at the hospital 6 to 24 hours after their stroke began. Currently, this procedure is only approved for patients who arrive within 8 hours. The study will compare patients who receive this clot-removal procedure plus standard stroke care with patients who receive standard care alone.

Many stroke patients arrive at the hospital too late to receive the approved clot-removal treatment, leaving them with limited options. This trial is designed to carefully test whether the procedure can safely help patients with specific imaging patterns even when they arrive many hours after their stroke began.

Do you qualify?

You likely qualify if…

you are 18 years or older
you have had a stroke with moderate-to-severe symptoms (a specific severity score of 6 or higher)
you can begin the procedure between 6 and 24 hours after your stroke started
brain imaging shows a blood clot in a major artery and a specific pattern (called 'target mismatch') suggesting the clot removal may help
you had no significant disability before your stroke

You likely don't qualify if…

you are pregnant
you have a serious bleeding disorder or are taking blood thinners at high doses
you have a severe allergy to contrast dye used in imaging
brain imaging shows large areas of permanent brain damage, hemorrhage, tumor, or other serious abnormalities
you are currently enrolled in another investigational treatment study

What participation looks like

If you qualify and agree to participate, you will undergo imaging scans (CT or MRI perfusion studies) to confirm you have the right pattern of injury. You will then be assigned to either receive the clot-removal procedure plus standard medical care, or standard medical care alone. Your recovery will be monitored, and you will return for an assessment at 3 months to measure how well you have recovered using a standard disability scale.

AI-generated summary from trial data · Jul 16, 2026 · Not medical advice

Trial locations(1 site)

China

Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang