Doctors are testing an experimental technique that's being touted as the first non-drug treatment for asthma. In the technique, called bronchial thermoplasty, tissue from the inside of the lungs that may block a person's ability to breathe, is burned away.

During a bronchial thermoplasty, a lighted catheter is inserted into your nose or throat and into the airways that fill the lungs. The tip, a wire basket, is inflated to touch the airway walls, then radiofrequency (RF) waves are beamed through the wires.

The RF waves heat the muscle tissue to 149 degrees, causing some of it to disintegrate, while apparently not scarring the airway's thin lining.

Researchers have compared the technique to a microwave oven, which cooks meat on the inside but doesn't scorch the outer layers. The idea is that overgrown muscle tissue in air tubes inside the lungs is responsible for some asthma cases, and bronchial thermoplasty can get rid of half of the thickened muscle.

In the first study, which followed 16 patients for two years, most reported improvements in breathing, as did those from a second pilot study involving 108 people. The clinical trial currently underway will enroll 300 severe asthmatics, and is being funded by device manufacturer Asthmatx.

However, there are risks involved. Side effects such as wheezing and coughing are common and may occur when the airways become irritated, and some have expressed concerns over potential unknown long-term effects, such as late scarring or weakened airways.

American Journal of Respiratory and Critical Care Medicine May 1, 2006;173(9):965-9

Yahoo News May 22, 2006