People with severe asthma are now being offered a radically different treatment option: a way to snake a wire inside their lungs and melt off some of the tissue that squeezes their airways shut. Bronchial thermoplasty isn’t for everyone, just a subset who wheeze despite today’s best medications. It is neither a cure nor without risk. But the new Alair system from California-based Asthmatx Inc., rolling out in the US this month, offers the first method of physically altering spasm-prone airways.
“It does seem to improve your ability to live with your asthma,” says Michael Silver from the Rush University Medical Center, Chicago, US.
On record: About 22 million Americans have asthma.
“It’s a very novel, very innovative treatment,” but only for the right patient, agrees William Calhoun of the University of Texas Medical Branch at Galveston, a spokesman for the American Academy of Allergy, Asthma and Immunology.
Opening up the airways
Around 22 million Americans have asthma, and a variety of medications offer good control for many. Still, asthma kills around 4,000 people a year in the US and hospitalizes at least half a million. Up to 15% of patients have severe disease, experiencing frequent attacks despite daily medication; too often they still need emergency-room care to end the gasping.
“It’s like slow suffocation,” says John Rapp, 59, of Arlington, Virginia, who wound up in the ER four or five times a year before participating in a study of bronchial thermoplasty.
Asthma is a two-pronged disease. First, inflammation in the lung’s branch-like airways narrows them and makes breathing difficult. The airways also contain a layer of muscle tissue that spasms if anything irritates the lungs. That muscle can double in thickness with repeated attacks, making airways increasingly twitchy.
Bronchial thermoplasty beams radio-frequency (RF) waves to heat up and shrink that muscle layer so that airways cannot constrict as badly during an asthma attack. In a half-hour outpatient procedure, doctors thread a flexible tube called a bronchoscope through the nose or throat, into the airways. An electrode at the tip beams RF waves through the airway wall to reach the muscle underneath without causing a burn.
Asthmatx estimates its Alair system, which the US food and drug administration (FDA) approved earlier this month, could target up to two million adults like Rapp. A company-funded study tested 288 adults at 30 medical centres. About two-thirds got bronchial thermoplasty. The rest got sham treatment to control for a placebo effect. Both groups stayed on their daily medications. It takes three treatments, a few weeks apart, to reach different parts of the lungs. But a year later, patients who got thermoplasty reported improvements in quality of life, fewer severe asthma attacks—26% of thermoplasty patients had one compared with 40% of sham patients—and, importantly, a major drop in ER visits.
Not without risk
The drawback: Thermoplasty irritates airways, meaning risks right after treatment include temporarily worse asthma, a partially collapsed lung and coughing up blood. Some 8.4% of thermoplasty patients required hospitalization, mostly on the day of treatment, compared with 2% of the sham group.
“If you’re willing to take that short-term risk, the long-term benefits are substantial in quality of life,” says Mario Castro of Washington University in St Louis, Missouri, who led the study.
But the big caution, says Dr Silver, is the unknown long-term effects. RF is used safely in other health conditions, and animal studies and patients tracked for several years do not suggest problems. But Dr Silver asks if scarring might show up years later and how long thermoplasty’s benefits last. The FDA is requiring Asthmatx to conduct a five-year study to find out.
Thermoplasty is not for patients currently experiencing worsening asthma or who have an infection or a bleeding disorder, the FDA says. And candidates must have realistic expectations, adds Dr Calhoun—thermoplasty does not reach smaller airways or treat asthma’s inflammatory side.
Back in Virginia, Rapp has not made an ER visit in the three years since his thermoplasty, and says the shortness of breath from a partially collapsed lung after one trial treatment cleared up quickly. “I can run around like a wild idiot, have fun with the dog, with my daughter,” he says. “I’m always going to have asthma symptoms, but this greatly reduces them.”
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