New Stroke Treatment Pumps Blood Backward to Reach Brain Tissue
A new treatment for stroke being pioneered at UCLA shows promise in saving the functional abilities of many people stricken by devastating brain attacks.
Most stroke treatments focus on dissolving the blood clot--typically by injection of an enzyme called tPA--before brain tissue can die. Although this is a much better treatment than anything available previously and has saved many lives, it is only 30% effective and patients run a small risk of bleeding in the brain. Stroke victims must also get to a hospital emergency room within about two hours of the onset of symptoms to have a realistic chance of the treatment succeeding.
The new treatment, called neuroperfusion, focuses instead on providing blood to the brain tissues “downstream” from the clot that are deprived of oxygen and nutrients. Using tiny catheters and a gentle pump, Dr. John G. Frazee and his team pump blood backward through veins in the brain so that it can reach the tissue whose normal blood supply has been cut off. The blood drains out through other veins.
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The procedure keeps brain cells alive and gives neurosurgeons more time to try to remove the clot. In many cases, the pressure from the pump itself is enough to dislodge the clot. Perhaps most important, the procedure extends the so-called “golden window”--the period after a stroke during which treatment can be effective--from the previous maximum of three hours to as long as seven.
Against a backdrop of skepticism from other neurosurgeons and even his own colleagues at UCLA, Frazee has claimed some initial success: He has tested the technique on eight patients so far under a Food and Drug Administration protocol designed to ensure its safety. But it has proved more than safe, actually reversing stroke symptoms in five. “There’s no other way to explain this but that it works,” he said.
William Boyer is certainly convinced. Boyer, a 61-year-old carpet installer from Sylmar, suffered a minor stroke last winter, keeling over in his garage. He was taken to Olive View Medical Center, where he had a larger stroke that left his left leg and hip paralyzed.
Fortunately, the Olive View resident physician on duty knew about Frazee’s program and recognized that Boyer was a good candidate because he had not been treated with tPA within three hours of his stroke. Boyer agreed to go to UCLA, but emergency transportation could not be arranged.
Ultimately Boyer, still in his hospital gown, climbed into his own car and his wife drove him to UCLA through rush-hour traffic. By the time they got there, six hours had elapsed.
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Frazee explained the technique and told him that he would be only the second person to undergo the procedure. Boyer is a golf fanatic and was concerned about not being able to play again, but he was also worried about the potential hazards of the experimental technique.
“We almost didn’t [do it]. But then I asked him, ‘Doctor, if you were in my position, would you do it?’ He said ‘Definitely!’ and we did it,” Boyer said.
Within 20 minutes after Frazee had started the neuroperfusion pump, Boyer had regained full function in his leg. Although the experimental protocol allows the machine to be operated for as long as six hours, “We shut it down then, because there was nothing else for it to do,” Frazee said. Angiography showed that the clot was simply gone, apparently dislodged by the back pressure and dissolved.
Boyer remained in the hospital for six days while physicians treated the erratic heartbeats that had caused his heart to make and throw off clots, but four days after he got out, he was back on the golf course--in the rain, yet.
“My wife could have killed me,” he said, “but I was fine.”
Stroke is a major problem in the United States. The incidence has been climbing since 1992, after a 25-year decline. Preliminary figures from the American Heart Assn. indicate that 550,000 Americans suffered strokes in 1995 and 158,061 of them died. Stroke is the third leading cause of death in this country, following heart disease and cancer, and is the No. 1 cause of admissions to hospitals and nursing homes.
Among those who survive, 70% are unable to perform the same job functions, 20% need help walking and nearly one-third need help caring for themselves, according to Dr. Jan Breslow, president of the heart association.
About 80% of strokes occur when a clot from the neck, heart or legs breaks loose and lodges in the brain. The remainder are caused by hemorrhaging from a burst blood vessel.
Until very recently, there was no treatment for either type of stroke, but tPA has changed the situation dramatically.
Unfortunately, many patients fail to recognize the symptoms of a stroke and even some physicians still fail to comprehend the possibilities for treating them, so patients do not get treatment in time for help to be effective. If Frazee’s approach is successful, it would allow patients more time to get to the hospital.
His technique is actually an outgrowth of one developed by Dr. Eliot Corday, a cardiologist who spent 50 years at Cedars-Sinai Medical Center. Corday, now 85, invented the retroperfusion technique for treating heart attacks, pumping blood backward through veins to reach threatened heart tissues. A device based on his work is manufactured by Neuroperfusion Systems Inc. of Irvine and has been approved by the Food and Drug Administration.
But it is not widely used for heart attacks “because there are so many other technologies that are just as good,” Frazee said. “That’s not the case in the brain.”
Corday persuaded Frazee, who is now co-director of the UCLA Stroke Center, to try the device in strokes. Frazee spent eight years experimenting with it in animals. “It was a very long, hard road,” he said. “Nobody wanted to be involved, and there were some pretty severe critics.”
The technique is not always effective, in part because the team’s treatment options are limited by their FDA-approved protocol. Frazee cites his seventh patient, who had a large clot. Treatment reversed the symptoms of his stroke and the team turned the device off after the allotted six hours. But the clot had not been dislodged, and the protocol, because it was designed to assess only safety, did not allow them to use tPA or anything else to dissolve it. Within 12 hours, the patient’s symptoms returned and he had the equivalent of a massive stroke.
The two other patients who did not respond were also elderly and their treatment was complicated by multiple medical problems, Frazee said.
“Eventually, we’ll be able to do something about the clot while we are keeping the tissue alive,” Frazee said.
UCLA has permission to treat 10 patients with the device. Frazee recently visited the FDA seeking permission to expand the protocol to two other centers and to increase the initial number of patients to 30. “We need to increase the number of patients studied,” he said.
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Forcing Blood Backward
A stroke damages brain tissue by cutting off blood flow to small areas of the brain. A new technique called neurperfusion forces blood backward through veins to nourish affected areas until the clot can be removed.
1. Physicians remove blood from the groin and inject it into the brain through veins in the neck.
2. In many cases, the reverse flow dislodges the clot, “curing” the stroke victim.
Reverse blood flow
Catheter
Blood clot
Catheters to the brain
Femoral artery catheter for blood source
Neuroperfusion pump
Source: UCLA
