The National Emphysema Treatment Trial (NETT)

Objectives:

To compare lung-volume–reduction surgery with medical therapy for severe emphysema, and to identify patient selection criteria for lung volume reduction surgery.

Background:

Lung-volume–reduction surgery has been proposed as a palliative treatment for severe emphysema. Effects on mortality, the magnitude and durability of benefits, and criteria for the selection of patients have not been established.

Subjects:

A total of 1,218 patients with severe emphysema underwent pulmonary rehabilitation and were randomly assigned at 17 centers to undergo lung-volume–reduction surgery (bilateral stapled wedge resection) or to receive continued medical treatment. Patients were randomized after a 6-10 week pulmonary rehabilitation period and patients with a forced expiratory volume in one second (FEV1) that was 20 percent or less of predicted and a homogeneous distribution of emphysema or carbon monoxide diffusing capacity 20 percent or less of predicted were not eligible for randomization due to poor post-surgery prognosis for death or functional improvement.

Conclusions:

Overall, lung-volume–reduction surgery increases the chance of improved exercise capacity but does not confer a survival advantage over medical therapy. It does yield a survival advantage for patients with both predominantly upper-lobe emphysema and low base-line exercise capacity. Patients previously reported to be at high risk and those with non–upper-lobe emphysema and high base-line exercise capacity are poor candidates for lung-volume–reduction surgery, because of increased mortality and negligible functional gain. (NEJM 2003;348:2059-2073).