|
It's called airway bypass, one of a trio of innovative experiments
-- including squirting a kind of glue into the lungs -- designed not to cure the lung destroyer that is the nation's No. 4 killer, but to ease breathing during its victims' last years.
And it comes amid a major government push to get more of the estimated 24 million Americans with breath-robbing COPD, or chronic obstructive pulmonary disease, diagnosed and treated sooner, to stall the need for such last-ditch care.
"This is a huge public health problem," says Dr. James Kiley, lung chief at the National Institutes of Health. "It's not going to get better unless we do something very aggressively."
Yet half of COPD sufferers don't know they have it. Aside from the eye-glazing name
-- a term for diseases once called emphysema and chronic bronchitis -- people tend to shrug off the main symptom, shortness of breath, as poor fitness or mere aging until their lungs are ravaged.
Healthy lungs inflate and deflate like balloons as they take in oxygen and remove carbon dioxide. The windpipe feeds air into bronchial tubes that resemble an upside-down tree with ever-smaller branches. Between these airways are tiny air sacs, elastic bubbles that stretch as they fill with air and then spring back into shape as used air rushes back out.
COPD destroys that elasticity. Airways collapse, blocking the way out. Air sacs distend with stale air, enlarging lungs and leading to COPD's distinctive barrel chest. Eventually, it becomes physically impossible to inhale deeply enough to get air to the lungs' remaining working spots.
Those lungs need emergency exits, decided Dr. Joel Cooper of the University of Pennsylvania.
Cooper helped pioneer an arduous surgery that cuts out portions of COPD patients' dead lung to make more space for remaining working lung. But few patients qualify; most have such widespread lung damage that there's no logical spot to remove, or
they couldn't survive the operation.
With airway bypass, Cooper invented a different approach: He threads a tiny needle through a tube inserted in the windpipe, down to airways about the diameter of a pencil. Smaller airways downstream are completely blocked. To route trapped air around them, he pokes up to a dozen holes through the bigger airway's wall and into surrounding air sacs. He wedges those holes open with stents, the same kind of metal scaffolding that cardiologists use to prop open clogged heart arteries.
The result: Tunnels for air to trickle out.
Does it work? No one yet knows. A pilot study of 28 patients treated abroad suggests it can help some people breathe easier. The first U.S. study, funded by stent-maker Broncus Technologies, is just beginning at more than a dozen hospitals. They aim to test up to 400 patients with advanced COPD, comparing those given the real procedure with some given a sham, just a tube down the throat.
[to top of second column]
 |
There is a serious risk: Doctors must avoid piercing the lung's many blood vessels, something that killed a German patient in that pilot study. Cooper, a financial consultant to Broncus, worked with the company to develop a probe that senses if a blood vessel is too close, so doctors can poke a different spot. Regulators are closely monitoring initial patients, to ensure the procedure is safe enough for the full study to proceed.
Other nonsurgical options under study:
-
Suctioning out dead air sacs and squirting a "biological glue" into them
-- made of proteins like your body uses to heal itself -- to seal them against more buildup. Only small numbers of patients have been tested in pilot studies, but scientists are reporting some improvement in shortness of breath and ability to walk.
-
Threading one-way valves inside bronchial tubes leading to the worst-clogged lung spots, to allow air and mucus to trickle out but no more air to be inhaled back in.
"Things like valves and stents and putting these biological substances in, they're a heck of a lot easier on patients" than surgery, notes Dr. Stephen Hazelrigg of Southern Illinois University, who is participating in some of the studies.
All three are still highly experimental -- the research is only for people who have run out of options, cautions Dr. Bartolome Celli of Tufts University, who outlined the study trio at an American Thoracic Society meeting last week.
But, it is "promising," Celli says. "We know from the surgery data that a significant number of patients do better. If we could do the same thing without the surgery, it follows that likely the results will be positive."
Better would be to catch COPD earlier, says NIH's Kiley. It takes a simple breath test. Inhaled medications minimize symptoms, and pulmonary rehabilitation is considered key in preserving lung capacity by teaching patients to get the most air from damaged lungs and strengthening muscles that help lung performance.
While it hasn't been scientifically proven, proper early care does minimize symptoms, "with the hope and expectation that that would prolong life," he says.
On the Web:
[Text copied
from file received from AP
Digital; article by Lauran Neergaard,
AP medical writer]
|
