KU Medical Center researcher published in NEJM study showing large-core strokes can be treated with vacuum to retrieve clot

If you or a loved one suffer a stroke where a large blood clot is causing brain damage every minute that the clot blocks the artery, you’d want someone to get it out.

A new study from the University of Kansas School of Medicine leads researchers to believe that suctioning out that clot is possible and even preferable to the current strategy of medication only.

The study, recently published in the New England Journal of Medicine and presented to the International Stroke Conference, found that blood clots once thought to be too large to be removed via surgery can actually be mechanically extracted with positive results.

“The study looked at patients with an already large area of the brain that was stroked out, due to a large vessel occlusion — a major artery blocked in the brain,” said Michael Abraham, M.D., associate professor of neurology and radiology in KU School of Medicine and co-author of the study. Abraham is also the director of stroke research.

Those major blockages lead to large portions of the brain not receiving blood flow, which in turn can lead to a loss of motor function or even death. Doctors call these type of strokes large-core strokes and typically focus on preventing life-threatening brain swelling and herniation, which is displacement of the brain tissue because of that swelling. Large-core acute (sudden and worsening) strokes are usually treated with medications.

The current medication for acute stroke “is not terribly effective for the large clots in the brain,” explained Colleen Lechtenberg, M.D., assistant professor of neurology in KU School of Medicine. The use of medication to treat acute strokes is called thrombolysis, and it’s usually the first-line treatment for strokes.

Using a ‘vacuum’ approach

Researchers looking for a better way to treat these large-core strokes turned to a solution they were already using for smaller strokes but previously thought was unadvisable for larger strokes.

In the international study, known as SELECT2, physicians removed clots in the brain by using either a stent or aspiration catheter. Through a small incision in the clinical trial participant’s leg, a small tube snakes through the body until it reaches the brain. The clot is then suctioned from the artery.

KU Medical Center was the second-highest enrolling study site worldwide, accounting for 35 of the 352 clinical trial participants.

This process of clot retrieval is known as a thrombectomy, and thrombectomies have been conducted for more than two decades on small clots. SELECT2 examined whether a thrombectomy could be effective on large-core strokes.

The results? Thrombectomies led to better results than the medication-only treatment. Of the trial participants who received thrombectomies, 37% of that group could walk independently 90 days after their stroke, compared to 18% in the medicine-only group.

Thrombectomies can be done quickly, Abraham said, sometimes as fast as 15 minutes. Time is of the essence in restoring blood flow to the brain to prevent further damage.

“We actually sometimes see the clot coming out through the tubing into this canister,” Abraham said. “When we pull it out, there’s always a small risk that small pieces will break off and go further out, but it’s better to have a small distal stroke than a larger more proximal (localized) stroke.”

Local clinical trial recipient’s story

One real-life example comes from Michael Augustine, who endured his second stroke in February of 2021. At The University of Kansas Health System, Abraham performed Augustine’s thrombectomy for his large-core stroke as part of KU Medical Center’s clinical trial.

The positive results of the thrombectomy, coupled with the care and therapy he received from the health system, set him on his path to rehabilitation. As a result, he was able to walk his daughter down the aisle at her wedding just 200 days after the stroke.

“That was a lot of the motivating factor for me, walking in the hallways [for physical therapy] to try to walk was so I could walk her down the aisle,” Augustine said.

“He used a cane for a while, just while he was building up strength and stability,” his wife Shari Augustine said. “But he gradually got rid of the cane and doesn’t really use anything now.”

Looking back, Augustine said he’s appreciative of those who helped in his recovery. “We were just completely impressed with the whole process,” he said. “Everybody was just very positive — a wonderful experience.”