National Emphysema Treatment Trial (NETT)

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Accession Number

Study Type
Clinical Trial

Collection Type
Open BioLINCC Study See bottom of this webpage for request information

Study Period

NHLBI Division

Dataset(s) Last Updated
January 3, 2018


Commercial Use Data Restrictions No

Data Restrictions Based On Area Of Research No

Available Data

The current release of the NETT study dataset includes follow-up data through May of 2013


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


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.


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.


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).

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