Asthma Bronchial Thermoplasty

Bronchial thermoplasty is a potential new asthma treatment currently undergoing clinical testing. Developed by Asthmatx, Inc. (a medical device company), bronchial thermoplasty has the potential to provide asthma relief to people who do not respond to conventional asthma treatment.

The American Journal of Respiratory and Critical Care Medicine reported results of a small bronchial thermoplasty clinical trial in it’s May 2006 edition. The study monitored sixteen adults with mild to moderate asthma that did not respond to current asthma treatments for two years after receiving bronchial thermoplasty treatment.

Clinical Trial Results

The results of the small bronchial thermoplasty study are encouraging. Two years after bronchial thermoplasty treatment, 75 percent of the participants reported that the asthma treatment allowed them to function better in daily activities.

Participants also reported:

  • an increase in symptom free days
  • less difficulty with asthma triggers
  • reduced peak expiratory flow readings.

Bronchial thermoplasty appears to be a well tolerated asthma treatment, with minimal side effects. Almost all participants said they would be willing to undergo the asthma treatment a second time.

Bronchial Thermoplasty Treatment

Bronchial thermoplasty uses radio frequency energy to relieve asthma symptoms. Because the procedure requires only light anesthesia, it can be performed on an outpatient basis. A small, flexible tube called a bronchoscope is inserted through the nose or mouth and guided into the lungs.

Once the bronchoscope is situated in the desired airway, a catheter is inserted through the bronchoscope. The tip of the catheter is inflated until it touches the sides of the airway wall. Radio frequency energy is then sent through the catheter, heating the smooth muscle walls of the airway to approximately 149° F. This temperature is sufficient to thin the smooth airway wall muscles without scarring or damaging them.

During an asthma attack, the smooth muscles of the airways contract. Because bronchial thermoplasty thins the muscle walls, they cannot narrow as much when irritants trigger asthma attacks, resulting in less symptoms and asthma relief. Participants in the bronchial thermoplasty study received three thirty-minute thermoplasty treatments that treated all accessible airways.

What’s Next for Bronchial Thermoplasty?

With such promising initial results, bronchial thermoplasty is receiving some attention as a possible new asthma treatment. The sixteen volunteers from the small clinical study will be monitored for an additional five years. Studies on the effectiveness of bronchial thermoplasty are ongoing: two larger bronchial thermoplasty studies come to an end in 2006. Similarly, a fourth study has begun that will monitor 300 participants at over 30 international medical centers.

Asthmatx Inc. points out that bronchial thermoplasty is an alternative to conventional asthma treatment. While the procedure is designed to reduce asthma symptoms, it is not intended to serve as a cure for the disease.

Resources

Cox, G; Miller, D; McWilliams, A; Fitzgerald, M; Lam, S. (27 October 2004). Bronchial thermoplasty: Long-term follow-up and patient satisfaction. meeting.chestjourn al.org/cgi/content/abstract/126/4/822S-b.

Genetic Engineering News. (1 May 2006). Encouraging results reported on new investigational asthma treatment; Outpatient procedure for asthma featured in American journal of respiratory and critical care medicine. www.genengnews.com/news/bnitem.aspx?name=989495.

Warner, J. (1 May 2006). New remedy for hard-to-control asthma. www.foxnews.com/story/0,2933,193827,00.html.