The device, from Asthmatx Inc., is a radiowave generator attached to a specially designed catheter. It is inserted into the airways during a procedure called bronchial thermoplasty.
There, it delivers radiofrequency energy to the smooth muscle lining the airway walls. This heats the muscle to reduce its mass in hopes of making it harder for the airway to narrow - the problem associated with asthma attacks.
Does it work? Michel Laviolette, MD, and colleagues at Laval University in Quebec, Canada, tested the device on 55 people with moderate to severe asthma. Fifty-three other patients, who received only standard asthma treatment, served as a comparison group.
For three two-week periods after treatment, all patients agreed to stop taking their asthma control medications except for steroid inhalers.
In these periods, patients who got the bronchial thermoplasty procedure had half the number of asthma attacks as those who did not get the procedure.
During the year following treatment, patients who got the procedure had about 40 more symptom-free days than they had the year before treatment. Those who did not get the procedure had only about 14 more symptom-free days.
Also, those who got the procedure needed about eight fewer puffs a week from their rescue inhalers. Those who did not get the procedure needed one fewer inhaler puff a week.
"The results suggest that in subjects with moderate to severe, persistent asthma taking inhaled corticosteroids, a single intervention with bronchial thermoplasty may provide significant and persistent clinical benefit," Laviolette and colleagues reported at the CHEST 2006 meeting of the American College of Chest Physicians, held Oct. 21-26 in Salt Lake City.
The study was funded by Asthmatx Inc.
SOURCES: CHEST 2006 meeting of the American College of Chest Physicians, Salt Lake City, Oct. 21-26, 2006. Chest, October 2006 supplement; vol 130: p 109S.
By Daniel DeNoon
Reviewed by Louise Chang