The surgery was first done in the 1950s and became popular in the 1990s as a way of restoring breathing power to victims of emphysema, which is otherwise irreversible and contributes to 100,000 deaths annually in the United States.
However, without a carefully controlled study, there was little clear proof that the operation actually improves people's lives. As a result, Medicare imposed a moratorium on paying for the surgery in the mid-1990s and sponsored a large study to examine its benefits.
The results, released Tuesday, show that fewer than one in five have meaningful improvement in their symptoms, and the operation has no effect on long-term survival. Nevertheless, the approach does help some patients, especially those whose exercise capacity is the worst.
The operation involves cutting away diseased portions of the lungs. Typically doctors take out about one-quarter to one-third of their total lung tissue, hoping to help the good parts of the lung work more freely and efficiently by removing the damaged bulk around them.
Lung reduction surgery "will likely be remade in the context of this trial and come back stronger than ever," said Dr. Keith Naunheim, chief of thoracic surgery at St. Louis University and a principal investigator of the National Emphysema Treatment Trial.
"The conclusions are rock solid. This is a very well-done trial," said Dr. Robert Cerfolio, chief of thoracic surgery at University of Alabama at Birmingham and one of the reviewers of the study.
However, he estimated that only about 10 percent of those with emphysema are suitable for the operation.
The study results were released at a meeting in Seattle of the American Thoracic Society and also will be published in Thursday's issue of the New England Journal of Medicine.
The study, begun in 1996, was conducted on 1,218 men and women at 17 hospitals around the country. They were randomly assigned either to get the operation or standard medical therapy.
After one year, 16 percent of the patients getting the surgery had significantly increased their exercise capacity as measured on an exercise bike, compared with 3 percent on medical treatment. On questionnaires, they also rated their quality of life as better. However, after two years, their conditions had returned to about the same levels as before the procedure.
The procedure was pioneered decades ago by Dr. Otto Brantigan, a Baltimore surgeon, but it quickly fell out of favor because of the high mortality rate — about one in five. In the early 1990s, Dr. Joel Cooper, a St. Louis surgeon, began doing the operation on emphysema sufferers too sick or old for lung transplants. Changes in surgical techniques had improved survival rates, and other doctors quickly began doing lung-volume reduction surgery.
"It spread across the country to other medical centers like wildfire," said Dr. Joshua Benditt, director of respiratory care services at the University of Washington Medical Center, who also was involved in the study.
Anecdotal evidence suggested the surgery was effective, but there were no studies of its worthiness. There also was the question of cost for the operation, which averages $30,000 to $35,000 and offers no cure, just relief for some patients.
"We know it's expensive and have to be careful about who gets the procedure," said Dr. Scott Ramsey of Fred Hutchinson Cancer Research Center, who directed an analysis of the operation's cost effectiveness.
Dr. Sean Tunin, a Medicare official, said the agency will reassess coverage for the operation and make new recommendations based largely on the latest study.
The study found that the surgery was most likely to help people whose emphysema was mostly in the upper lobes of their lungs and whose exercise capacity was low. Researchers said one contribution of the study is identifying those for whom the operation is especially risky.