New device can suck out stroke-causing blood clots
Published Tuesday, June 8, 2010 4:08PM EDT
A tiny "vacuum cleaner" that can suck out blood clots before they cause a stroke might sound like science fiction, but Canadian researchers say such a device exists – and it works.
Already, 27 Calgary patients have been rescued from strokes by the device, Dr. Mayank Goyal told the Canadian Stroke Congress Tuesday afternoon.
The tool is called the Penumbra System of Continuous Aspiration Thrombectomy and it works by breaking down and gently sucking out stroke-causing blood clots, to open up blocked vessels.
If used within a few hours of an ischemic stroke – the most common kind of stroke -- the device can reverse the effects of the stroke by restoring blood flow to the brain, preventing permanent brain damage.
"This unique new procedure is really quite miraculous," Goyal, the director of the Seaman MR Research Centre at the University of Calgary says.
The clod-busting procedure is performed a bit like an angioplasty. It involves threading a tiny catheter in a blood vessel through the groin, which is then fed up to the neck.
Then, an even smaller catheter is threaded into the brain beside the clot. The clot is then vacuumed out.
The device is credited with saving the life of Shane Neufeld. The 36-year-old had a stroke when an artery in his neck became torn, leading to a blood clot.
He remembers developing a crushing headache after a hockey game, followed by blurry vision, and then collapsing, unable to move.
"Then 15 minutes later my wife comes down and she saw me. And she knew and she called the ambulance right away," he remembers.
Doctors used the device to remove the clot. One year later, Neufeld still has trouble with speech but is grateful to be alive.
"I might have been dead if they don't suck out the clot properly," he says. "I am getting better with my speech and it takes time but if they didn't suck out the clot properly I properly can't even talk."
Currently the best treatment for ischemic strokes is the clot-busting drug tPA, which must be administered within three hours of the onset of stroke to work.
"But that's a chemical reaction and that takes time. This Penumbra system goes inside and sucks the clot up," Canadian Stroke Network spokesperson Dr Antoine Hakim told CTV. "Instead of waiting for a drug to melt the clot, to bust it, you have a system to suck the clot out."
Goyal notes that if the clot is in one of the bigger blood vessels, tPA just doesn't do the job fast enough.
"Sometimes it takes an hour or over an hour. In most cases we have been able to get vessels open in 15-20 minutes [with the Penumbra system]," he said.
This new process might be able to help those patients who get to hospital more than three hours after a stroke.
But not every stroke can be treated with the device. Only really large strokes can be vacuumed out and the procedure would not work for the 20 per cent of strokes that are hemorrhagic strokes. As well, the procedure is not easy to perform.
"It requires years of training to be able to do this," says Goyal. "It places enormous demands on the interventionalist, on the imaging specialists, and on the emergency team that gets the patient to a designated stroke care facility. Teamwork is key for success."
Goyal says his team's recent research has helped tease out which types of strokes can be best treated with the device, noting that current medication treatments would still be used for those patients who aren't suitable for treatment with the device.
"This promising technique has the potential to curb many of the devastating effects of large strokes," says Heart and Stroke Foundation spokesperson Dr. Michael Hill.
"Patients may benefit in a number of ways including improved outcomes and improved quality of life."
According to the Heart and Stroke Foundation of Canada, more than 50,000 strokes occur in Canada each year, and of them more than 14,000 Canadians will die.
With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip