New Heat Technology Helps Asthma Patients

It thins out airway muscle for better breathing, study finds.

By Ed Edelson
HealthDay Reporter
Wednesday, March 28, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

WEDNESDAY, March 28 (HealthDay News) -- A new technology that uses radio waves to burn off overgrown muscle in the airways of asthma sufferers helped them breathe better, have fewer symptoms and use less medication, researchers report.

The technique, called bronchial thermoplasty, now is being tested in a larger trial that could lead to its approval by the U.S. Food and Drug Administration.

"This is the first trial that shows a fairly remarkable response," said co-researcher Dr. John D. Miller, an associate professor of surgery at McMaster University in Canada. "It also is the first non-drug treatment for asthma to be developed recently."

The report is published in the March 29 issue of the New England Journal of Medicine.

With thermoplasty, doctors snake wires that can emit radio waves into the lungs. These radio waves emit heat that can burn off some smooth muscle in the airways.

The basic idea behind thermoplasty is that "smooth muscle sits around the airway, and when it contracts it makes the airway narrower," Miller explained. "When the amount of muscle is reduced and it is triggered to contract, there is nothing to contract."

The trial included 112 people with moderate to severe asthma. Half underwent three sessions of thermoplasty; the other half had their usual drug treatment.

One year later, air flow was much better in patients receiving thermoplasty -- 39 liters per minute compared to 8.5 liters per minute for those getting standard treatment.

The thermoplasty group also reported an average of 40 symptom-free days, compared to 17 for the others, with fewer asthma symptoms and less medication used.

"Now a second trial, which uses information from this one, moves forward," Miller said. "It is similar to the first trial except that it will use a sham procedure in the control arm."

Full enrollment of 350 asthma patients for the new trial has been completed, said Dr. Elliot Israel, an associate professor of medicine at Harvard Medical School and a member of the research group. "They are in different phases of treatment, with some on their second or third sessions," Israel said. The participants will be followed for up to two years to assess the results of the treatment.