More stroke patients may soon be eligible for a new procedure that surgically removes blood clots blocking large arteries in the brain, in the wake of dramatically positive results reported Wednesday at the International Stroke Conference 2015 in Nashville, Tennessee.
Designed to reduce the severity of an ischemic stroke and limit potentially devastating disability afterward, the procedure employs a stent and catheter device. Together with other recent studies, evidence released at the conference supports its use in more stroke cases, the first major breakthrough in treatment since the development of clot-busting drugs.
Four trials in recent months have reported the method is safe and effective in removing clots in the brain’s largest blood vessels — the carotid and middle cerebral arteries — which are linked to the most serious disabilities after a stroke. Results in two, known as ESCAPE and EXTEND IA, were shared at the conference and are in the online New England Journal of Medicine.
An expert in this intervention surgery, Tudor Jovin, director of the UPMC Stroke Institute and leader of ESCAPE’s University of Pittsburgh arm of the study, had anticipated the positive reports.
“Information from different parts of the world is converging and showing the same benefit,” Jovin said. “It’s been my passion, what I believed ever since my residency in neurology. I felt there was a lot to be done to help these worst-of-the-worst patients.”
In an early analysis at the conference, a third study, SWIFT PRIME, also reported that patients treated with a combination of clot-busting drugs and the surgery had better outcomes 90 days afterward than patients treated with the IV drugs alone. The study, with 196 patients, was conducted at 39 hospitals in the United States and Europe. Maine Medical Center in Portland was among those hospitals, enrolling four patients.
“I am proud to be part of this seminal global research, bringing world-class care to patients with stroke in Maine,” Dr. Robert Ecker, medical director of Maine Medical Center’s Neuroscience Institute, said in a news release. “Our patients who have participated in the research have benefited from this breakthrough technology, and we are looking forward to helping others in the future.”
The studies used new versions of retrievable stents, called “stentrievers,” to remove clots from cerebral arteries. A stent-tipped catheter is put into a groin artery and extended upward through the body to the brain, where the clot has been detected. The mesh-like stent is opened up and captures the clot; the pieces are drawn out as the catheter is retracted, restoring blood flow to the area.
In most of the studies, patients were first treated with the clot-dissolving drug tPA. If they still had a clot shown in brain imaging and were in the intervention group, they had the surgery. The scan determines if the damage to the brain is small enough to be helped by intervention.
Addressing safety concerns, ESCAPE also concluded that the deaths from all strokes were markedly reduced with the surgery. With standard care, the rate of death was two in 10 patients; with the intervention, it dropped to one in 10. Among better outcomes for patients with surgery, 53 percent were able to live independently without major disability, compared with about 30 percent among those treated only with the drug tPA. The ESCAPE study, conducted at 22 sites, included 316 patients who fit the criteria for the surgery and tPA and arrived for care within 12 hours of their stroke.
Even better results were reported by the smaller EXTEND IA: 24 out of 35 patients who had the surgery returned to independent living, compared with 14 in the tPA-only group. EXTEND IA studied advanced brain imaging to select patients who might be helped by the surgery and researchers credited that for the better outcomes.
The latest news reversed earlier studies that found the stent-catheter method was not as effective as tPA treatment.
Jovin said those earlier studies motivated a group of researchers to design the new trials. He is principal investigator of another clinical trial, tracking a larger patient population around Barcelona, Spain, which plans to release its results in April.
The turnaround came after a 500-patient Dutch study known as MR CLEAN reported in October that acute ischemic stroke patients had better functional outcomes 90 days after being treated with the stent-catheter. Most were first given tPA before being assigned to surgery and no-surgery groups. Good outcomes were reported even when treatment started up to six hours after the stroke began. Time for effective use of tPA was recently expanded to 4½ hours.
The American Heart Association and the American Academy of Neurology are expected to convene experts in the coming weeks to draft a statement updating guidelines for stroke treatment.
Jovin cautioned that not all hospitals will be able to offer the procedure; that the infrastructure of a state-of-the-art stroke center does the best job of selecting patients for the treatment, performing the procedure and providing care.
The Pittsburgh region’s two comprehensive stroke centers, based at UPMC Presbyterian Hospital, Oakland, and Allegheny General Hospital, North Side, have stroke neurologists, staff and facilities that have been using this procedure on patients for some time.
Ashis Tayal, medical director of the Allegheny General Hospital stroke center, said the new stentriever is more effective than earlier versions.
“We can open up the vessel 60 to 80 percent of the time,” he said, “much better than in the past.
“Patients do better, their strokes are less severe because you’ve opened up the artery. The area of damage is smaller; therefore, the person’s disability is less severe,” he said.
Distributed by Tribune Content Agency LLC. The Bangor Daily News contributed to this report.