National Emphysema Treatment Trial (NETT)

April 13, 2016 updated by: National Heart, Lung, and Blood Institute (NHLBI)
To evaluate the long term efficacy, morbidity and mortality associated with medical therapy with lung volume reduction surgery (LVRS) as compared to medical therapy alone and to define patient selection criteria. The trial, conducted in conjunction with a patient registry, is supported by the NHLBI, the Centers for Medicare and Medicaid Services (CMS), and the Agency for Healthcare Research and Quality (AHRQ).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

BACKGROUND:

LVRS is intended primarily for those patients whose chronic obstructive pulmonary disease (COPD) is predominantly emphysema. Emphysema is characterized anatomically "by abnormal, persistent enlargement of the airspaces distal to the terminal bronchioles, accompanied by the destruction of the airspace walls and without obvious fibrosis". The loss of the lung architecture leads to compressible peripheral airways that close at higher than normal lung volumes (early airway closure). The increased compliance and the air trapping from early closure leads to hyperinflation of the lung, over distention of the chest wall, a flattened, disadvantaged diaphragm, and ventilation-perfusion mismatch. In the 1950s and 1960s, Dr. Otto Brantigan theorized that surgical excision of multiple wedges of lung would reduce lung volumes, thereby restoring the outward elastic pull on the small airways and reduce airway obstruction. Dr. Brantigan reported that the surgical excision of lung tissue resulted in significant clinical improvement in some cases, but mortality was high. With little objective data and high mortality, the procedure did not gain widespread acceptance.

The experience that diaphragmatic and chest wall function could be restored in emphysema with lung transplantation renewed interest in Dr. Brantigan's work. Improvements in surgical technique have opened the possibility of performing surgical excisions of lung tissue. Recent reports on LVRS have shown improvements in FEV1, FVC, TLC, RV and dyspnea and quality of life assessments.

These reports generated enormous excitement among patients and their doctors. Many centers around the country started performing LVRS with the result that hundreds of patients had the procedure, despite the preliminary nature of the results, the lack of rigorous patient selection criteria and the lack of information on long term outcome. Basic questions remain such as which patient should have the surgery, what protocol should be followed, what physiological tests should be obtained, and what is the long term efficacy of the technique on morbidity, mortality, and quality of life. The mechanisms of benefit and the full cardiopulmonary consequences are unknown.

The concept for the trial originated in the NHLBI Workshop on Evaluation and Research in Lung Volume Reduction Surgery. The initiative was reviewed and approved at the May 1996 National Heart, Lung, and Blood Advisory Council meeting. The Requests for Proposals were released in June, 1996.

DESIGN NARRATIVE:

In the trial, 1218 eligible patients were randomized to receive either medical therapy (610) or medical therapy with LVRS(608). LVRS was performed by median sternotomy or video-assisted thorascopic surgery (VATS). Centers randomized their patients to either a) medical therapy alone versus medical therapy with LVRS by median sternotomy, b) medical therapy alone versus medical therapy with LVRS by VATS, or c) medical therapy alone versus medical therapy with LVRS by median sternotomy versus medical therapy with LVRS by bilateral VATS. Medical therapy included pulmonary rehabilitation and education. Direct comparisons of the two surgical techniques were possible only at the centers that performed both techniques. All arms included intensive pulmonary rehabilitation. The primary endpoints were survival and functional improvement as assessed by maximum workload. Secondary endpoints included morbidity, improvement in pulmonary function, quality of life and performance of activities of daily living. Follow-up exams, including history, physical exams, pulmonary function tests, exercise tests and quality of life assessments, occurred after pre-operative rehabilitation and six and twelve months after surgery and every twelve months thereafter. Recruitment ended July 31, 2002 and follow-up ended in December, 2002.

Study Type

Interventional

Phase

  • Phase 3

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

No older than 100 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Men and women with end-stage emphysema.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Heart, Lung, and Blood Institute (NHLBI)

Investigators

  • Steven Piantadosi, Johns Hopkins University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

December 1, 1996

Primary Completion (Actual)

December 1, 2005

Study Completion (Actual)

December 1, 2005

Study Registration Dates

First Submitted

October 27, 1999

First Submitted That Met QC Criteria

October 27, 1999

First Posted (Estimate)

October 28, 1999

Study Record Updates

Last Update Posted (Estimate)

April 14, 2016

Last Update Submitted That Met QC Criteria

April 13, 2016

Last Verified

April 1, 2009

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 218

Plan for Individual participant data (IPD)

Study Data/Documents

  1. Individual Participant Data Set
    Information identifier: NETT
    Information comments: NHLBI provides controlled access to IPD through BioLINCC. Access requires registration, evidence of local IRB approval or certification of exemption from IRB review, and completion of a data use agreement.
  2. Study Protocol
  3. Study Forms

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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