Bronchial Thermoplasty Brings Long-Term Relief to Severe Asthmatics

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Army Hopes Treatment Will Allow Return-to-Duty for Ill Soldiers

By Annette M. Boyle

Col. Eric A. Crawley, MD

Col. Eric A. Crawley, MD

HONOLULU — Pulmonologists at Tripler Army Medical Center in Honolulu have pioneered a treatment that has brought relief to nearly a dozen military health system or VA patients with severe asthma during the past two years — and may have the potential to enable similar patients to remain on active duty in the future.

The procedure, bronchial thermoplasty, uses radiofrequency energy (RFE) delivered through an expandable wire array passed through a standard bronchoscope into the lungs to heat and destroy some of the excess airway smooth muscle (ASM) that lines the bronchial tubes in severe asthma. By decreasing the volume of smooth muscle, thermosplasty reduces the force of the muscle spasms that cause breathing problems during an asthma attack.

“The patients we treat have moderate to severe asthma that is uncontrolled on standard asthma medications. Generally, they are on a lot of medication and may wake up during the night because they are unable to breathe,” said Col. Eric A. Crawley, MD, medical chief of pulmonary and critical medicine at Tripler Army Medical Center, Honolulu.

Bronchial thermoplasty is performed in 3 separate treatment sessions each scheduled approximately 3 weeks apart.  Click the figure to expand a full-size image in a new tab.

Bronchial thermoplasty is performed in three separate treatment sessions each scheduled approximately three weeks apart. Click the figure to expand a full-size image in a new tab.

Typically patients with moderate to severe asthma, steps 5 or 6 on the National Asthma Education and Prevention Program (NAEPP) guidelines, are on high-dose inhaled corticosteroids and long-acting beta-agonists. They may also be taking omalizumab, an injectable monoclonal antibody, or oral corticosteroids.

Patients undergo three treatments, each separated by three weeks. The first treatment reduces ASM in the right lower lobe, the second addresses excess muscle in the left lower lobe and the third addresses the upper lobes.

“We do the procedure on an outpatient basis with general anesthesia through a laryngeal mask airway. Patients generally go home the same day, though two have stayed overnight for observation. Studies suggest there’s about a 3% chance that a patient may have to be admitted after the procedure. Typical symptoms post procedure include worsening cough, wheezing and phlegm, but those usually go away in three to five days,” Crawley said.

The procedure does not cure asthma. Patients still need medication but may be able to discontinue systemic corticosteroids and reduce other drugs, he noted.

Following bronchial thermoplasty (BT), “the literature shows that patients report a better quality of life, fewer emergency department visits and less absenteeism,” Crawley added. No patients in the three major randomized controlled trials or at Tripler have experienced serious side effects, including intensive care admission or mechanical ventilation.

The long-term outlook for patients is quite promising. A recently published follow-up study of 162 of the 190 patients in the Asthma Intervention Research 2 trial found that five years after the procedure, patients continued to benefit from thermoplasty. On average, patients experienced a 44% reduction in exacerbations and 78% drop in emergency department visits compared with the year before the procedure. Previous studies had monitored patients for two years.1

The long-term data also supported the procedure’s safety. The researchers noted that respiratory-related hospitalizations and adverse events did not increase during the study period and that pre-bronchodilator forced expiratory volume in one second (FEV1) remained stable during the five years, even though daily inhaled corticosteroid dosages dropped an average of 18%. No structural abnormalities attributable to the procedure were detected in high-resolution computed tomographic scans.

“The absence of an increase in respiratory AEs and asthma (multiple symptoms) AEs over a 5-year period provides further support for the long-term effectiveness of BT. These improvements with BT were noted in the presence of reduced use of maintenance medications. Collectively, these data raise the possibility that BT might be a disease-modifying therapy,” concluded the study authors.

The procedure is effective and durable, but can it help the Army retain soldiers? “We don’t know yet,” Crawley said. So far, patients treated at Tripler have included veterans, retirees, dependents and a few active-duty soldiers who were already in the process of being separated because of their conditions. “To date, no one has looked at military patients or the effect on exercise performance.”

The military has an interest in the answer to that question. While symptomatic asthma after age 12 has been an exclusion criteria for military enlistment, a significant portion of the active duty force has asthma likely due to underreporting on enlistment and the presence of undiagnosed asthma that may have been exacerbated by desert conditions. Previous research showed that deployment to Iraq and Afghanistan was associated with more than a 50% increased risk of new-onset asthma compared to nondeployed soldiers. 2

Crawley said he and his colleagues hope their latest research project will provide additional insight on the value of BT for severe asthmatics who want to remain in the service. They are currently enrolling 15 patients in a pilot study to determine if bronchial thermoplasty can improve asthma control sufficiently so that soldiers can stay on active duty.

“Enabling a soldier to stay in could result in a seven-figure savings to the military when you include the cost of recruiting, training, equipment and disability payments,” Crawley noted.

1Wechsler ME, Laviolette M, Rubin AS, Fiterman J, Lapa E, et al. Asthma Intervention Research 2 Trial Study Group. Bronchial thermoplasty: Long-term safety and effectiveness in patients with severe persistent asthma. J Allergy Clin Immunol. 2013 Dec;132(6):1295-302.

2Szema AM, Peters MC, Weissinger KM, Gagliano CA, Chen JJ. New-onset asthma among soldiers serving in Iraq and Afghanistan. Allergy Asthma Proc. 2010 Sep-Oct;31(5):67-71

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