Novel clot-busting technique boosts recovery from stroke
Thursday, February 16th 2006, 2:49 pm
By: News On 6
KISSIMMEE, Fla. (AP) _ Like pouring Drano directly on a clog, doctors dramatically improved stroke survival by dripping a clot-dissolving drug right onto a blockage choking off the brain's blood supply.
Many patients given this experimental treatment had stunning recoveries within a day, often without the speech loss and paralysis that can follow a stroke, doctors reported Thursday.
A second study found that people given the treatment were 65 percent more likely to be able to walk, talk and function normally three months after their strokes than those given standard care.
``We're very encouraged by these results,'' said that study's leader, Dr. Joseph Broderick, neurology chief at the University of Cincinnati. ``We found that we were either partially or completely able to open the blocked artery 69 percent of the time.''
The promising results from the two small studies were presented at a conference of the American Stroke Association.
Strokes kill about 163,000 Americans each year and are a leading cause of long-term disability. Most are due to clots that deprive an area of the brain of blood, causing it to die.
The usual treatment is intravenous doses of the clot-busting drug, TPA, but it must be given within three hours of the start of symptoms, doesn't always work, and sometimes causes dangerous bleeding in the brain.
Doctors tested a novel way to give TPA to try to overcome these three problems. It is similar to angioplasty, the procedure to open clogged heart arteries. A tube is inserted in a vessel in the groin and guided to the clot _ in this case, in the head rather than near the heart.
TPA is dripped directly onto the clot through the tube instead of having to make its there through the bloodstream.
One-fourth of the 128 patients given this treatment in the last decade at the University of California at Los Angeles had dramatic improvement of stroke symptoms within a day, study leader Dr. Doojin Kim reported. Many of the rest improved, too, but less dramatically.
About 90 percent survived, compared with 74 percent of stroke patients who get standard intravenous TPA. Most not only survived but had excellent final outcomes. Bleeding in the brain also was less frequent with the novel approach.
The second study involved 73 patients with severe strokes who first got intravenous TPA, then dripped treatment if the first approach didn't work. Some also received ultrasound to further break up the clot, given through a tiny device passed through the same tube that carried the TPA.
The results: Twice as many suffered the side effect of bleeding in the brain, but twice as many clots were dissolved _ the main goal of treatment, Broderick reported.
``There's definite promise'' in the technique, said Dr. John Mailer, associate director for clinical trials at the National Institute of Neurological Disorders and Stroke, the federal agency that funded both studies and has agreed to sponsor a larger one based on these results.
Broderick's study also was partly paid for by Ekos Corp., a company in Bothell, Wash., that makes the ultrasound tube device.
The new technique appears best for people under age 80 and those with major rather than mild strokes, doctors said. Broderick estimated that up to half of stroke patients might qualify.
That would make it of significant benefit _ only about 30 percent of clots currently dissolve with intravenous TPA alone, said Dr. Gregory Del Zoppo, a stroke expert from the Scripps Research Institute in La Jolla, Calif., who had no role in the studies.
The challenge now is figuring out which patients would do best with these clot-dissolving strategies as opposed to trying to pull the clot out with a new corkscrew-like device that came on the market last year.
Both techniques promise to give stroke patients another option if the basic intravenous TPA treatment fails, but the relative risks and benefits of each need further study.