Gerard Silvestri, M.D., Professor of Medicine in the Division of Pulmonary and Critical Care Medicine and Director of Bronchoscopy at the Medical University of South Carolina, was the first pulmonologist in the state to offer patients with medication-refractory severe asthma a new treatment option—bronchial thermoplasty.
Bronchial thermoplasty using the Alair® system (Boston Scientific, Natick, MA), which was approved by the US Food and Drug Administration in 2010 in select patients with severe asthma whose symptoms are not controlled by medications, attempts to achieve symptom control by reducing, through controlled bursts of thermal energy, the smooth muscle mass that tends to build up and become hyperresponsive in patients with severe asthma. During bronchial thermoplasty, a catheter with an expandable electrode array is advanced into the airway via a bronchoscope. When expanded, the electrode sits snugly in the airway (Figure 2) and can deliver a 10-second burst of radiofrequency energy that is carefully calibrated to reduce the mass of smooth tissue in the airway without affecting surrounding tissue.
Treatment is administered over three sessions, with each of the lower lobes of the bronchi treated in the first two sessions and the top of both bronchi treated in the third.
The Asthma Intervention Research 2 (AIR-2) trial, which randomized patients to either bronchial thermoplasty or to a sham therapy, showed substantial improvements in secondary outcomes for those treated with bronchial thermoplasty, prompting speedy approval of the Alair system by the US Food and Drug Administration even though the study’s primary end points were not met.1 Impressive gains were noted in the posttreatment period (6-52 weeks), including a 32% reduction in severe exacerbations (ie, those that required systemic corticosteroids or doubling of the dose of inhaled corticosteroids), significantly fewer visits to the emergency room, and fewer days absent from work (1.32±0.36 days/year vs. 3.92±1.55 days/year).
Patients may experience some increased airway inflammation in the first few weeks after the procedure, but these should resolve in time. The procedure has been shown to be safe at five years, and the durability of its effect has been demonstrated to two years.2
According to Dr. Silvestri, "Early results have shown that bronchial thermoplasty can make a life-changing improvement in the symptoms of patients with severe asthma." To learn more about bronchial thermoplasty, watch the video interview with Dr. Silvestri below.
1 Castro C, Rubin AS, Laviolette M, et al, for the AIR-2 Trial Study Group. Effectiveness and safety of bronchial thermoplasty in the treatment of severe asthma. Am J Respir Crit Care Med. 2010;181:116-124. Available at dx.doi.org/10.1164/rccm.200903-0354OC.
2 Wahidi MM, Kraft M. Bronchial thermoplasty for severe asthma. Am J Respir Crit Care Med. 2012; 185(7):709-714. Available at dx.doi.org/ 10.1164/rccm.201105-0883CI