Bronchoscopic thermal vapour ablation for upper-lobe emphysema

2.1 Emphysema is a chronic lung disease that typically happens with chronic obstructive pulmonary disease. In emphysema, the walls of the air sacs (alveoli) in the lungs weaken and disintegrate. This leaves behind abnormally large air spaces that stay filled with air even when the patient breathes out. The most common symptoms of emphysema are shortness of breath, coughing, fatigue and weight loss. Recurrent illnesses (such as chest infections) often lead to exacerbations, for which patients may need hospitalisation. Emphysema is usually related to smoking, but other risk factors include air pollution and an inherited alpha-1-antitrypsin deficiency.

2.2 Treatment options include pulmonary rehabilitation (exercise training, breathing retraining, and patient and carer education), stopping smoking, and using inhaled or oral bronchodilators and corticosteroids. Oxygen therapy may also be needed in more severe cases. Lung volume reduction surgery is an option for patients who experience breathlessness, and whose pulmonary function tests and CT scans show severe disease and enlarged air spaces. Surgery can be done thoracoscopically or using an open approach. Endoscopic lung volume reduction techniques include implanting valves or coils. The aim is to reduce the morbidity and mortality associated with conventional surgery.

2.3 Bronchoscopic thermal vapour (steam) ablation for upper-lobe emphysema is usually done using general anaesthesia. A bronchoscope is passed down the airway to the diseased areas of the lung. The most severely affected and hyper-inflated lung segments are targeted for treatment. A catheter is used to deliver a patient-specific predetermined dose of thermal vapour through the bronchoscope. A balloon at the tip of the catheter is inflated to seal off the targeted area. The dose of thermal vapour depends on the mass, volume and diseased state of the affected area. The thermal vapour ablates the diseased tissue, which the body removes through the natural healing process. Multiple treatments can be done over time, targeting different segments as the patient's disease progresses. This procedure is not done when there is proven active infection in the lung. The removal of disease tissue results in a reduction of lung volume and subsequent remodelling of the lung. Lung volume reduction typically happens gradually over a 4- to 6‑week period. Respiratory symptoms may worsen in the first 2 to 4 weeks after treatment.