Radiofrequency ablation of airway smooth muscle for sustained treatment of asthma: preliminary investigations

Bronchial thermoplasty is a procedure now being tested in humans for the treatment of asthma. Current studies focusing on safety are encouraging. The procedure, which causes extensive ablation of airway smooth muscle (ASM), is well tolerated, and there is a sustained reduction in airway responsiveness to methacholine. Two assumptions underlie the development of this procedure: 1) ASM is a vestigial tissue; and 2) that treatment directed at ASM alone will provide sustained symptomatic and physiological improvement in asthmatic humans. Even if this procedure is efficacious, it must be safe in the long-term. Current studies in animals and humans suggest that this is very likely to be the case. While bronchial thermoplasty may have a broad application, especially for patients who wish for a permanent amelioration of their symptoms or have difficulty adhering to medical regimens, the compelling use of this procedure is for patients who are inadequately controlled on current drug therapy or who cannot adhere to therapeutic regimens. The application of this procedure for the treatment of asthma is currently being considered by regulatory agencies, and study centres are currently disseminated throughout North America and Europe. Within the next 1-2 yrs, a profile of the potential role of this therapy in human asthma should be developed fully.