Bronchial thermoplasty study

Mar 30 2007

A new report published in the prestigious New England Journal of Medicine (NEJM) shows that patients treated with bronchial thermoplasty, the first non-drug treatment for asthma, demonstrated an overall improvement in asthma control.

Co-Principal Investigators, Dr. Gerard Cox, respirologist at St. Joseph's Healthcare Hamilton's Firestone Institute for Respiratory Health, and Professor at McMaster University, and Dr. John Miller, Division Head of Thoracic Surgery at St. Joseph's Healthcare Hamilton and McMaster University authored the study. The study revealed improved asthma control at one year following the bronchial thermoplasty procedure.

The publication entitled, "Asthma Control during the Year after Bronchial Thermoplasty", showed that patients treated with bronchial thermoplasty, compared to another group that did not receive the procedure, showed significant positive changes such as: decreases in asthma attacks, increases in days with no asthma symptoms, improvement in quality of life, reduction in using medication, and an improvement in asthma control.

"These findings are very encouraging and are consistent with earlier trial results on bronchial thermoplasty," explains Dr. Cox. "These results make us hopeful that bronchial thermoplasty may be a new option for asthma patients who have asthma symptoms despite use of current drug therapies."

Bronchial thermoplasty is a minimally invasive procedure that reduces the amount of airway smooth muscle that is responsible for the constriction of airways in asthma patients. Using a flexible bronchoscope through the nose or the mouth, a routine procedure. physicians treat small to medium sized airways with Bronchial Thermoplasty (BT). The BT device generates radio frequency/thermal energy and reduces areas of underlying smooth muscle in the airways. The procedure is completed in three treatment sessions, each lasting less than one hour, and spaced apart by about three weeks. The procedure, like many other flexible endoscopy procedures, is done under light anesthesia, and the patient returns home the same day.

The objective of the Asthma Intervention Research (AIR) Trial, led by Drs. Cox and Miller, as part of a global clinical trial, was to examine the effectiveness and safety of bronchial thermoplasty as a treatment for patients with moderate or severe asthma. The randomized controlled trial included 112 patients between the ages of 18-65 at 11 centers in four countries, and followed these patients for one year after treatment.

Several years ago, Dr. John Miller began limited bronchial thermoplasty procedures in patients who were scheduled to have lung surgery. "We saw that this particular way of treating the airway had a profound effect on the smooth muscle and not much else, Dr. Miller explains. "The amount of smooth muscle is significantly reduced by thermoplasty and we recognized that this procedure might therefore be an appropriate treatment for people with asthma."

"I'm quite pleased to say that our experience suggests that the Bronchial Thermoplasty procedure is quite well-tolerated, and it holds considerable promise for patients with asthma."

Asthma is a common disease in which the airways in the lung become inflamed, excess airway mucus is produced, and airways narrow when muscles within the airway walls contract. During an asthmatic attack, in response to an asthma trigger such as an allergen or irritant, the airway smooth muscle may contract leading to airway narrowing and breathing difficulties. Asthma currently affects more than 2 million people in Canada.