The therapy targets the thickened muscles that line the airways. Although current medications are reasonably successful in controlling the contraction of these smooth muscles in the majority of asthma patients, about five percent of patients with severe persistent asthma continue to suffer from excessive bronchoconstriction. Reduction of airway smooth muscle helps reduce the ability of the airways to narrow in response to a trigger.
“Bronchial thermoplasty is for those people who require moderate to high doses of inhaled steroids and a long-acting beta agonist to control their asthma symptoms,” UAB pulmonologist Mark Dransfield, MD, says. “By decreasing the capacity of the airways to constrict, this treatment should help patients with severe asthma gain better control over their disease and see improvements in their quality of life.”
The procedure, developed by Asthmatx Inc., uses a specially designed catheter and electrode array to deliver a precise amount of heat energy to remove the excess smooth muscle. The treatment is performed in three outpatient procedures, typically three weeks apart.
Prior to its FDA approval in 2011, bronchial thermoplasty was used only in clinical trials. “Even now it is available only on a limited basis because a lot of insurance payers are not covering the procedure, while others still have not decided if they will cover it,” Dransfield says. “The major expense related to the process is the cost of the catheter that delivers the heat energy. It costs $2,500 to $3,000 so it is not something that most patients can pay out of pocket. They need insurance coverage.”
If a patient’s asthma is controlled with medicines, Dransfield doesn’t recommend that they have the procedure. “Often, there can be an increase in symptoms following the procedure,” he says. “About one in 10 people are likely to be admitted to the hospital sometime during the three treatments so we don’t want to treat people if they are otherwise doing well.”
Dransfield, who is the medical director of the UAB Lung Health Center, points out that the clinical trial researchers did not enroll patients who had out-of-control asthma, so he is unsure if the procedure can help these patients. “We didn’t enroll patients who were frequently in the hospital or emergency room so we don’t yet know the risk versus benefit for these people,” he says. “They probably stand to benefit, but are likely at higher risk for flare ups at the time of the procedure. We don’t want to do the treatment when patients are unstable.”
Bronchial thermoplasty is expected to complement asthma maintenance medications by providing long-lasting asthma control and improvement in asthma-related quality of life for patients with severe asthma. The American Journal of Respiratory and Critical Care Medicine reports that the procedure reduced asthma attacks by 32 percent and emergency room visits for respiratory symptoms were reduced by 84 percent. “Across the board, it reduces mild, moderate and severe flare ups by reducing the overall number of these instances,” Dransfield says. “It may also reduce the need for albuterol and oral steroids.”
Bain Peto of North Alabama testifies to the effectiveness of bronchial thermoplasty. Peto had suffered with asthma for 35 years before her physician referred her to Dransfield. Since receiving the treatment at UAB, she has a new lease on life. "I've had asthma since seventh grade, and I remember taking at least eight pills a day. I also had a big nebulizer with me at all times," Peto says. "I couldn't do anything that required physical exertion. Now I'm walking outside with my neighbor and I have a completely different attitude. I have an eight-year-old daughter who deserves to have playtime with me. That was part of my motivation to have the surgery."
Peto says she takes half the amount of steroids since having the bronchial thermoplasty and hopes to stop them altogether when pollen season ends. "It is also great that I can lose weight when I stop the steroids," she says.
UAB currently is involved in post-marketing study to determine if the beneficial treatment effect of bronchial thermoplasty extends to five years post-therapy. “Trials show that the procedure is safe out to five years, and there is no evidence of unexpected loss of lung function. CT scans done one year after treatment also show no evidence of structural problems in the lungs,” Dransfield says. “The trial we are participating in now will help us determine if the reduction in flare ups and improvement in quality of life we are seeing in the first two years will extend to five years.”
In April 2012, Dransfield and the UAB team will be able to begin treating patients outside of the clinical trial. “If any physician considers sending patients to us, please note that we will do an extensive work-up on them to see what is driving their symptoms,” Dransfield says. “A number of people who appear to have refractory asthma don’t have it at all. Symptoms may result from allergies or from not taking medications correctly, among other things. We have to be careful who we treat.”
