New stent retriever procedure safe, effective for patients with stroke

Feb 4 2012

Oregon Stroke Center at OHSU enrolls 35 patients in nationwide trial, most of any study site; director says new procedure will be 'game changer'

A new way of opening blocked arteries in the brain using a removable stent system in people suffering strokes brought remarkably positive results in how those patients recovered from the strokes, according to a study presented this morning at the American Stroke Association's annual conference in New Orleans.

The interventional procedure was performed on more than 140 stroke patients at 18 medical centers throughout the United States. Stroke specialists at Oregon Health & Science University treated the most patients of any medical center in the country, performing the procedure on 35 patients who were part of the trial.

"I really think this is going to be a game changer," said Wayne Clark, M.D., a co-author of the study and director of the Oregon Stroke Center at OHSU. "These results showed that not only could we open up the blood vessel but we can help many more people recover fully from their strokes when this 'stent retriever' procedure is used."

Clark was part of the OHSU stroke team that performed the procedures, which also included specialized neuro-interventionalists led by Stanley Barnwell, M.D., Ph.D., an associate professor of neurological surgery and diagnostic radiology at OHSU.

The procedure was performed on patients who were within eight hours of suffering an "acute ischemic stroke" - a medium to large stroke caused by a lack of blood flow to the brain, often caused by a blood clot. During the procedure, stroke doctors use a catheter to guide the small stent from the groin area to the brain. The stent -made of platinum-titanium mesh and called the Solitaire- Flow Restoration Device - is guided into the part of a patient's brain arteries where a blood clot has formed.

The stent expands the interior walls of the artery and allows blood to get to the patient's brain immediately to prevent as much brain damage as possible. The clot seeps into the mesh of the stent. Then, after five minutes, the stent and clot are removed together.

The study was called the SWIFT trial - for Solitaire with the Intention for Thrombectomy. It compared the new stent retriever procedure to a traditional clot removal intervention for strokes. In the traditional procedure, a corkscrew-like device is twisted into the clot and the clot is gently pulled out. Sometimes, more than one attempt is needed to remove the clot.

The study results showed that, compared to the traditional retriever device, the new stent retriever resulted in more people who had an "excellent neurological outcome" - 33 percent with the corkscrew procedure compared to 56 percent with the stent. It also resulted in fewer people dying from their strokes - 17 percent with the new stent versus 38 percent with the corkscrew device.

"This device represents an exponential improvement in stroke therapy," Barnwell said. "The results in regards to opening plugged-up brain arteries and allowing full recovery in a large number of these patients is outstanding. Interestingly, this device is one of the easiest to use and safest of all the devices now used to treat stroke."

Both Jean Bentley, from Portland, and Patty Ladd, from Salem, had very good outcomes from the stent procedures at OHSU after they suffered their strokes, in 2010.

"I think it's awesome," said Bentley, who was 55 when she suffered her stroke in June of that year. "If it can get a clot out a lot faster and get the person up and going again, I think it's an awesome, awesome procedure. I know it saved my life."

Bentley, an insurance claims analyst, suffered her stroke at work in a downtown Portland office building, at about 5:45 a.m. on June 29. By the time she got to OHSU, she had no vision and no use of her left leg and left arm.

The stroke team performed the procedure within about two-and-one-half hours. "The next thing I knew I was awake in the room and I remember moving my left arm," Bentley said.

Bentley was back at work within about a week of the stroke. The only minor effect she still has from the stroke is some coordination issues at times - "and it's not something you'd even notice if you saw me," she said.

On August 15, 2010, Ladd, a counselor who was then 68, was a passenger in a car waiting in a drive-through lane at a Salem coffee shop when she lost the ability to speak and her right side became paralyzed.

Her friend driving the car got her to a Salem hospital - one of the hospitals in OHSU's telestroke network - after which Ladd was airlifted to OHSU.

She remembers being taken out of the car at the Salem hospital, "then I don't remember anything else until I woke up (at OHSU) the next morning." The procedure was performed on her within about five hours of her first symptoms.

Two mornings later, "I got up and dressed and was walking around the halls of the ICU," she said. She was released from OHSU that day.

"I was totally cognizant of the fact that with a stroke, the chances of me getting back to normal can be very low," Ladd said. "So the fact that it turned out like it did was amazing to me, from the get-go.

"It is just absolutely astonishing."

Source: Oregon Health & Science University