02/11/2015 12:07 EST | Updated 04/13/2015 05:59 EDT

Canadian-led study confirms game-changing approach to stroke care

Canadian and international researchers have shown a new approach to treating some devastating strokes could dramatically lower the toll these brain attacks cause.

The new technique, which involves extracting large clots from the brain arteries they block, should substantially lower the number of deaths caused by stroke and make an enormous difference in post-stroke quality of life, several research teams reported at the American Stroke Association conference in Nashville, Tenn.

"Basically we saw that people who would end up in a nursing home were walking home back into their lives," Dr. Michael Hill, director of the stroke unit at Calgary's Foothills Hospital and senior author of one of the papers, said in an interview. Hill, a neurologist, is also a professor at the University of Calgary.

"So it's a pretty big deal for us in the stroke world."

Hill's study, which reports results of a clinical trial testing the procedure in five countries, was published online Wednesday by the New England Journal of Medicine, which also published an Australian paper investigating the same technique. Both were presented at the Nashville conference, along with a third that found similar results.

All three were stopped early when it became clear that the new procedure was more effective than the treatment it was tested against, the standard of care for strokes caused by clots. The standard treatment is to use a drug, tPA, which breaks up the clot. It must be used as quickly as possible and is not effective if it is not given within 4 1/2 hours of a stroke occurring.

"This is a once-in-a-generation advance in stroke care," the head of one study, Dr. Jeffrey Saver, stroke chief at the University of California, Los Angeles, told The Associated Press.

An independent expert, Dr. Lee Schwamm of Massachusetts General Hospital, called it "a real turning point in the field." For many patients, "this is the difference between returning home and not returning home," although only certain types of patients can be offered it, he said.

Stroke care "needs to be completely changed" to make the treatment more widely available, said Dr. Walter Koroshetz, acting director of the National Institute of Neurological Disorders and Stroke.

The new procedure requires doctors to work swiftly to diagnose the cause of the stroke. Some are caused by bleeding in the brain and cannot be treated this way.

Once the cause is determined to be a clot, the clot-busting drug is administered. But with really large clots — which cause the most damage in survivors — the drug sometimes isn't enough to open the artery and re-establish blood flow to the brain.

With this new technique, doctors made an incision in the patient's groin and snaked a catheter up into the brain, to the site of the clot. They threaded a retrievable stent — a small tube — over the clot, trapping it inside. The stent was then removed.

In the Canadian-led study, people who had their clots removed were nearly 50 per cent less likely to die from their stroke, and survivors had substantially fewer consequences of the brain attack.

Still, this is a technique that cannot be rolled out overnight. Even getting hospitals to use tPA on all patients who would benefit from it has been tough slogging, said Dr. Stephen Phillips, a Halifax-based stroke neurologist who was an investigator in the Canadian-led trial.

The new technique involves more sophisticated imaging and requires the skills of highly trained interventional radiologists, Phillips said. Even at his institution — the Queen Elizabeth II Health Sciences Centre, which took part in the trial — adjustments will need to be made to be able to offer this level of care around the clock.

Talks have been underway to try to find ways to extend this type of care to the rest of Nova Scotia, he said, but "we don't have a clear plan of action yet about how we're going to do it."

"It's not straightforward. There are lots of logistical hurdles."

The Canadian-led study was funded in part by Medtronic, which makes the retrievable stent.

— With files from The Associated Press.