The catheter heats the small airways to exactly 65 degrees Celsius.
Asthma is a chronic disease of the bronchial, the air passages leading to and from the lungs. Some 235 million people currently suffer from asthma worldwide, and while 90 to 95 percent of asthma sufferers respond well to medication, for a small minority medication alone is not enough.
For these patients, University Hospitals Leuven now offers bronchial thermoplastie: three one-hour sessions during which a catheter is inserted into the patient’s respiratory tract via a bronchoscope. Heat, exactly 65 degrees Celsius, is applied to specific predetermined locations in the small airways, thus reducing muscle contractions in the tissue and improving breathing. To ensure the patient’s comfort, the treatment is carried out under general anesthesia.
Professor Lieven Dupont and Professor Christophe Dooms, pulmonologists at University Hospitals Leuven, have begun treating the first patients with the new technique. “Because the airways are made of smooth muscle tissue, inflammation can cause violent contractions resulting in breathlessness, especially after physical exertion,” says Professor Dupont. “The heat of the bronchoscopic treatment counters this by penetrating the lining of the airways and permanently reducing the smooth muscle tissue. This decreases the intensity of the muscle contractions.”
Conventional asthma medication reduces inflammation in the airways and widens the airways. “And that works well for the vast majority of asthma sufferers. But some patients have unusually strong muscle contractions. Although medication reduces inflammation and relaxes the airway temporarily in these patients, the muscle layer in the trachea remains active and can even become more active, despite the medication. This new technique is thus intended for people with a severe form of asthma that is not treatable with medication alone.”
“Just breathing warm air is not enough. The treatment requires targeted heat of exactly 65 degrees Celsius. 75 degrees is too hot because it causes tissue damage, and 55 degrees is not efficient enough to achieve the desired effect. The pulmonologist monitors everything on a screen via the bronchoscope and has an anatomical map of all the branches of the airways marked with the targets he must treat. It is precision work.”
In Europe, bronchial thermoplastie is currently only being carried out in a limited number of lung centres. University Hospitals Leuven is leading the way in Belgium. Although the positive effects of the three-session treatment are long-lasting, its price tag is rather high. “A new 2,500-euro catheter is needed for each of the three treatment sessions. It is an expensive treatment, and it is not currently reimbursed.”
“We look forward to seeing the long-term results of our own patients. Studies show that the new technique has a modest but significant effect. Patients show fewer airway contractions and 32 to 84 percent of patients report fewer asthma exacerbations. These results are not as remarkable as medication, but for patients whose asthma is caused by a hyperactive muscle layer, this technique is an interesting alternative.”