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National Emphysema Treatment Trial (NETT)

This study is ongoing, but not recruiting participants.
Information provided by National Heart, Lung, and Blood Institute (NHLBI)

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Descriptive Information Fields
Brief Title  National Emphysema Treatment Trial (NETT)
Official Title 
Brief Summary

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).

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 Phase Phase III
Study Type  Interventional
Study Design  Treatment, Randomized
Primary Outcome Measure 
Secondary Outcome Measure 
Condition  Emphysema
Lung Diseases
Lung Diseases, Obstructive
Chronic Obstructive Pulmonary Disease
Intervention  Procedure: Lung volume reduction surgery
MEDLINE PMIDs 10469970,   10593802,   11269488,   11596594,   11596586,   10680095,   12153963,   12759480,   12759479,   12759478,   12759481,   12615634,   15115992,   15364757
Links Related Info This link exits the ClinicalTrials.gov site
Recruitment Information Fields
Recruitment Status  Active, not recruiting
Enrollment 
Start Date  December 1996
Completion Date December 2005
Eligibility Criteria 

Men and women with end-stage emphysema.

Gender Both
Ages
Accepts Healthy Volunteers No
Contacts ††
Location Countries 
Administrative Information Fields
NCT ID  NCT00000606
Organization ID 218
Secondary IDs ††
Study Sponsor  National Heart, Lung, and Blood Institute (NHLBI)
Collaborators ††
Investigators 
Investigator:     Steven Piantadosi     Johns Hopkins University    
Information Provided By National Heart, Lung, and Blood Institute (NHLBI)
Verification Date February 2005
First Received Date  October 27, 1999
Last Updated Date June 23, 2005

 †    Required WHO trial registration data element.
††   WHO trial registration data element that is required only if it exists.




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