Blood-Diverting Catheter May Help Stroke Victims
New device that redirects flow shows promise in pilot study
THURSDAY, Feb. 5, 2004 (HealthDayNews) -- A new device that redirects blood flow from the torso to the brain appears to extend the treatment window for stroke victims beyond the critical three-hour time frame, a small pilot study suggests.
Called NeuroFlo, the device is actually a catheter with two balloons, according to the study's lead researcher, Dr. Morgan S. Campbell III, director of interventional neurology at the Alabama Neurological Institute in Birmingham.
"You insert it into the groin area, in the femoral artery," he says. "The device sits at the level of the kidneys and then you inflate it. The balloon creates resistance to blood flow, and that resistance shifts more blood flow to the head." One balloon sits above and one sits below the kidney's arteries.
The results will be presented Friday at the American Stroke Association's annual meeting in San Diego.
By restoring the blood flow to the brain quickly, it's possible for the cells in the stroke area to recover. The approach, known as the blood volume theory, has been studied before but until now has not been shown to work, says Campbell, who emphasizes that further research is needed.
"If it works out, it is several years away at best" before it might come into common use, cautions Dr. Larry Goldstein, director of the Stroke Center at Duke University Medical Center and a spokesman for the American Stroke Association (ASA).
The new device "extends the treatment window," Campbell says. Typically, stroke victims must arrive at the hospital within three hours of their stroke symptoms onset to be treated effectively with clot-busting drugs. But in the pilot study, the average time lag between onset of the symptoms and the treatment was 7.5 hours.
About 700,000 Americans will suffer a stroke this year, according to the ASA. About 80 percent will have an ischemic stroke, in which a clot blocks an artery. The others will have a hemorrhagic stroke, caused by ruptured blood vessels.
The pilot study evaluated 17 patients, all of whom had suffered an ischemic stroke. Ten of the 15 who arrived at the hospital conscious improved during the hour-long procedure. Two died, but the deaths were attributed to the progression of the stroke, not to the treatment.
Twelve of the 16 patients who received monitoring by ultrasound had at least a 15 percent increase in brain blood flow velocity, an indirect measurement of blood flow volume. The average increase was 25 percent. Ten of the 15 conscious patients achieved higher scores, as determined on the National Institutes of Health Stroke Scale, an assessment tool used by doctors. And a month later, six of the 15 survivors had physical functioning termed "good" on a commonly used disability scale.
Another expert, Dr. Marc Mayberg, chairman of the department of neurological surgery at the Cleveland Clinic, says the approach warrants further study.
But he offers a caveat. "It's an uncontrolled pilot study, and it's impossible to make any conclusions on the efficacy of the treatment," he says.
Without a control group of patients not treated with the catheter device, Mayberg says, it's impossible to know if the treated patients would have gotten better even without the device.
But the small pilot study does suggest "it is feasible to do this and relatively safe," Mayberg adds.
CoAxia, Inc., the manufacturer, plans to seek approval from the Food and Drug Administration to conduct a larger clinical trial.
To improve the outcome after a stroke, consumers are urged to recognize the warning signs, which can include: sudden numbness or weakness of the face, arm or leg, particularly confined to one side of the body; confusion or trouble speaking; difficulty with walking, dizziness, or loss of balance or coordination; sudden and severe headache without apparent reason; and trouble seeing in one eye or both eyes. If a stroke is suspected, immediate medical attention is crucial.
To learn about types of strokes, visit the National Institute of Neurological Disorders and Stroke. For the warning signs, go to the American Stroke Association.