Approximately 22 million Americans suffer from asthma. Patients with severe asthma experience significant morbidity and disability despite the use of multiple medications. Until very recently, the only therapeutic options for asthma involved the delivery of medications (such as steroids and bronchodilators) through inhaler devices as well as systemic medications (such as leukotriene inhibitors and monoclonal antibody targeted therapies). Unfortunately, these modalities of therapy cannot reverse the inevitable smooth muscle hypertrophy that develops in the airway of asthma patients. Hypertrophy causes severe bronchospasm and reduced airway lumen diameter, resulting in severe asthma symptoms that often require hospital admission. Rising health care costs due to recurrent hospital admissions for asthma exacerbations has been a concern that needed to be addressed.
Bronchial thermoplasty is a novel intervention for patients with severe asthma that involves the delivery of thermal energy to the airway wall resulting in a sustained reduction in the airway smooth muscle mass. It uses radiofrequency waves generated by the Alair System (Asthmatx, Inc) that are delivered through a catheter that is inserted through the working channel of the flexible bronchoscope.
Each activation treats less than an inch of the airway, and therefore the physician sequentially activates the probe in order to thoroughly deliver the treatment.
Bronchial thermoplasty is an outpatient procedure that is done either under conscious sedation or general anesthesia and takes between 30 minutes to an hour to complete. Since there is no pain sensing nerve fibers in the airways, this procedure does not cause any pain. However, patients generally develop some shortness of breath and on occasion asthma symptoms for a few days following the procedure. This is one of the reasons why the procedure needs to be divided into three separate bronchoscopic procedures. As an additional measure of safety, each procedure is done two weeks apart. Most patients are discharged home the same day of the procedure to resume their normal daily activities.
Bronchial Thermoplasty has been shown to be effective in patients with severe asthma who are symptomatic despite treatment with high doses of inhaled corticosteroids and a long acting beta blocker (the current standard of care). There is no data to support the use of this technology for patients with mild or moderate asthma at this point.
THE EVIDENCE AND THERAPEUTIC OUTCOMES
Several clinical trials have documented the effectiveness of Bronchial Thermoplasty, with most data originating from the Asthma Intervention Research (AIR) Database. This includes evidence from randomized trials comparing it with the standard of care and even a multicenter, randomized, double-blind, sham-controlled trial. In fact, the latter was the largest sham-controlled trial ever performed in the field of pulmonary medicine. These trials have shown that Bronchial Thermoplasty improves asthma-specific quality of life, decreases severe exacerbations in patients with severe asthma and decreases healthcare utilization (including less hospital admissions and emergency department visits). The other key finding was that the results were sustained for up to one year (based on the follow up of the sham trial) Even in patients that have been followed for more than a year there have been no reports of therapy failure or recurrence of symptoms. The studies on Bronchial Thermoplasty have consistently demonstrated that this procedure is safe with an acceptable risk of complications (similar to those seen with other bronchoscopic procedures: minor bleeding, bronchospasm, and pneumothorax).
Patients need to be advised to stay on their inhaled corticosteroids (and other disease modifying medications) even after Bronchial Thermoplasty to prevent the recurrence of muscle hypertrophy. A patient’s desire to discontinue their inhalers is therefore not an indication for Bronchial Thermoplasty. Early referral of patients with severe asthma is suggested. At this point, insurance carriers require a substantial amount of documentation to prove that the patient does qualify for this intervention, which can delay the procedure. This issue is expected to improve as third party payers realize the benefits when the cost of Bronchial Thermoplasty is compared with the costs of hospital admissions.
Article by Jorge Guerrero, MD
Dr. Jorge Guerrero, MD, graduated from Universidad Javeriana School of Medicine in 2002. He then completed a fellowship at Harvard Medical School in Boston, Massachusetts in Adult Tracheobronchomalacia Novel Clinical Research. Next, Dr. Guerrero completed an Internal Medicine Residency at Tufts University School of Medicine in Boston, Massachusetts and a Pulmonary, Critical Care, and Sleep Medicine fellowship at Georgetown University School of Medicine. Dr. Guerrero went on to complete another fellowship at Harvard Medical School – Beth Israel Deaconess Medical Center in Boston, Massachusetts in the Division of Interventional Pulmonology. Since finishing his third fellowship, Dr. Guerrero became a member Central Florida Pulmonary Group in Orlando as of August 2012. Dr. Guerrero may be contacted at 407.841.1100 or by visiting www.cfpulmonary.com.