2 The procedure
2.1.1 Leakage of air from the lungs into the pleural space can lead to collapse of the lung and difficulty in breathing. Persistent air leaks from the lungs can occur after thoracic operations or trauma, or because of underlying pulmonary disease.
2.1.2 Persistent air leaks may initially be treated with a temporary chest drain to remove the air from the pleural space. If air continues to leak from the lung, a surgical repair may be needed. Pleurodesis may be an alternative option.
2.2.1 Insertion of endobronchial valves for persistent air leaks aims to reduce or eliminate airflow through the leaks so that the rest of the lung can function normally. It may also allow the tissues around an air leak to heal so that the leak stops.
2.2.2 The procedure is done using flexible bronchoscopy with the patient under sedation or general anaesthesia. The area of air leak is identified by occluding suspected segments with a saline-filled balloon and monitoring the air flow. A one-way valve mounted on a flexible catheter is passed through the bronchoscope and inserted into the target airway.
2.2.3 More than 1 valve may be inserted during a procedure. Valves may be removed when the defect on the lung surface has sealed.
2.2.4 Several different devices are available for this procedure.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.
2.3.1 A case series of 40 patients treated by insertion of endobronchial valves reported a complete cessation of air leak in 48% (19/40) of patients, partial cessation in 45% (18/40), and no change in 5% (2/40) (range of follow-up 5–1109 days).
2.3.2 A case series of 7 patients (8 procedures) reported successful removal of chest drains in 5 patients at a median of 16 days after valve insertion.
2.3.3 A case report of 4 patients treated by insertion of endobronchial valves reported a reduction in pneumothorax in 3 patients. Re-expansion of both lungs was reported in 1 patient within 2 days and at 6 months in another patient. Improvement of the pneumothorax in 1 lung was reported in a third patient (timing unclear).
2.3.4 In the case series of 7 patients, a 'reduced' air leak returned after valve removal in 1 patient (15 days after the procedure).
2.3.5 The Specialist Advisers listed efficacy outcomes as duration of air leak, reduction or resolution of air leak, reduction in hospital stay, reduction in intensive care or high-dependency unit stay, reduction in the use of non-invasive or intermittent positive pressure ventilation, and improvement in health-related quality of life.
2.4.1 Valve migration was reported in a case report (discovered on chest X-ray 2 months after the procedure). The valve was removed 5 months after the procedure.
2.4.2 Initial valve malpositioning (needing redeployment) was reported in the case series of 40 patients (numbers of patients not stated and timing of event not described).
2.4.3 Expectoration of a valve was reported in the case series of 40 patients (number of patients not stated and timing of event not described).
2.4.4 Recurrent chest infection was reported in a case report at 5 months after the initial procedure; the 2 valves were removed.
2.4.5 Partial atelectasis of the lower lobe was reported in a case report (timing unclear; no further details).
2.4.6 The Specialist Advisers listed anecdotal adverse events as haemoptysis, respiratory failure, distal infection or pneumonia, and granulation tissue formation around valves. They listed death as a theoretical adverse event. The Specialist Advisers also listed recurrence of air leak or pneumothorax.