By using radiofrequencies in a procedure called bronchial thermoplasty, researchers heat the muscle lining and bronchial tubes to decrease bronchial inflammation. They hypothesize that there is an excess of smooth muscle, which may narrow the airways and cause inflammation. More info at the New England Journal of Medicine narrative video.
"At the end of the one-year trial, the subjects who received bronchial thermoplasty treatments reported an average of 10 mild asthma attacks over the course of the study – roughly 50% fewer than those who received asthma drugs only. The researchers defined "mild" asthma attacks as those that did not warrant a hospital visit...The patients who received the experimental heat treatment were free of asthma symptoms for 40% of days during the year, on average. Those who did not receive thermoplasty were symptom-free for only 17% of the days."http://www.newscientist.com/article.ns?id=dn11487&feedId=online-news_rss20