To understand how endobronchial valves can improve symptoms in patients with emphysema and to convey current opinion regarding optimal patient selection.
Summary Surgical lung volume reduction can, under certain circumstances, improve forced expiratory volume in one second (FEV1), indices of resting hyperinflation and quality of life  in patients with emphysema. However, a significant proportion of patients (between one-quarter and one-third) fail to derive significant benefit from the procedure. This in itself might not matter were it not that, in large series, the mortality rate has been at least 4–5% [1–3]. While this risk might be acceptable if success were guaranteed, it is less appealing otherwise. Another issue is that, in order to reduce mortality and morbidity, most groups impose safety criteria so that patients who are too disabled are not eligible for lung volume reduction surgery (LVRS).
These factors suggest a need for a treatment which is more likely to be effective and is less dangerous and/or reversible. Two principal approaches have been described. In one, an extrapulmonary pathway is created, which allows increased expiratory flow from the lung. In the other, which will be discussed in this article, an endobronchial blocker or valve is positioned with the aim of achieving distal collapse; the tissue engineering approach, using instilled glues, is a variant of this technique.
- ©ERS 2008