University of Pittsburgh Researchers to Present Portion of Results From the National Emphysema Treatment Trial at the American Thoracic Society Conference in Seattle
SEATTLE, May 20, 2003 Lung volume reduction surgery as a treatment for emphysema increases the chances of improvement in exercise capacity, lung function and quality of life without increasing mortality, according to a study presented today at the 99th American Thoracic Society (ATS) International Conference in Seattle.
A subgroup of patients with upper lobe emphysema and a low baseline exercise capacity prior to surgery also were found to have a significant survival benefit in addition to the functional improvement. The two-year survival rate in this subgroup was greater than twice that of patients in a non-surgical control group.
Physicians from the University of Pittsburgh Medical Center (UPMC), who participated in the 18-center National Emphysema Treatment Trial (NETT), presented a portion of the findings at the ATS conference this morning.
This study proves that, in a properly selected patient, lung volume reduction surgery has become the only available treatment other than supplemental oxygen to increase the survival rate for these patients, said Frank C. Sciurba, M.D., associate professor of medicine, division of pulmonary, allergy and critical care medicine at UPMC and principal investigator for the Pittsburgh arm of the study. However, it is important to note that this surgery is not for everyone and, in fact, there are subgroups of patients where surgery may be harmful.
In lung volume reduction surgery, surgeons remove about 20 to 35 percent of the diseased portion of the lungs. The procedure is not a cure and does not stop the disease, but it offers patients an alternative to lung transplantation.
The study enrolled 1,218 patients with severe emphysema between January 1999 and July 2002. All participants in the study first underwent six to 10 weeks of pulmonary rehabilitation and then were randomized to either lung reduction surgery (608) or continued medical treatment (610).
Among the 290 patients with upper lobe predominant emphysema and low post-rehabilitation baseline exercise capacity, surgery patients had both a lower mortality rate and a greater likelihood of improvement in exercise capacity after 24 months. However, among the 220 patients with non-upper lobe predominant emphysema and high post rehabilitation baseline exercise capacity, surgery patients had a greater mortality rate with little chance of exercise improvement.
While those patients with upper lobe emphysema clearly gained from lung volume reduction surgery, non-upper lobe patients with higher baseline exercise capacity were found to be poor candidates for this procedure, Dr. Sciurba said.
Emphysema, the destruction and enlargement of the lungs' peripheral air sacs, affects an estimated two million people in the United States. Smoking causes the majority of cases. Because of emphysema, the lungs are over-expanded at all times and the movement of air from the chest cavity is greatly reduced.
The study was funded by the National Heart, Lung and Blood Institute (NHLBI) and the Health Care Financing Administration (HCFA).
UPMC, which houses one of the leading lung transplant programs, also is one of the most experienced centers performing lung surgery in the country and a major contributor to the available medical literature in lung reduction surgery. Additionally, Dr. Sciurba authored one of the first papers detailing how lung volume reduction surgery works in a 1996 publication of the New England Journal of Medicine (NEJM).