Emphysema is a progressive and severe form of COPD. Patients with emphysema have significant destruction of their lung tissue. This destruction of tissue results in marked narrowing of the airways and difficulty with getting oxygen into the blood stream. There is no medication to bring back the lung tissue lost due to emphysema. Patients with emphysema frequently have portions of their lungs taken up by large dilated airspaces that we call bullae. These bullae compress the existing lung tissue and prevent it from working properly. Reducing the size of bullae, or removing them entirely, has been shown to help patients afflicted with severe emphysema.
Initially, surgeries were performed on emphysema patients to reduce the size of the bullae, but only a portion of emphysema patients were helped by these procedures and complications were common. Research into so-called non-invasive measures to help these patients has resulted in the development of a valve which, when placed in the airway, usually at the time of a bronchoscopy, has been shown to reduce the size of bullae and improve patient function. These valves have a one way circuit which allows air to come out of the bullae, but not go back in, thereby reducing their size and effect on normal lung tissue.
There have been several styles of valves studied. The FDA has just approved the Zephyr Valve as the first endobronchial valve available that is a valve that is positioned in the airways to help reduce the effects of large, emphysematous bullae on normal lung tissue.