Lung surgery aids some emphysema patients. (Breathe Easier).

Surgery in which doctors remove diseased portions of the lungs clearly helps some people with emphysema, a new study finds. But the likelihood of benefit depends on the location of the damaged tissues and the patient's health going into surgery.

The findings should guide physicians in predicting which patients will get the most out of such operations, says Steven Piantadosi of Johns Hopkins Medical Institutions in Baltimore. He and a team of more than 300 researchers nationwide report their findings in the May 22 New England Journal of Medicine.

Healthy lungs provide a flexible honey-comb of air sacs where blood is recharged with oxygen. But in emphysema patients, some lung tissue loses its elasticity. Since such tissue doesn't billow as well, patients have trouble inhaling fresh air and expelling low-oxygen air. The damaged tissue also receives poor circulation, further reducing the oxygen reaching the blood system.

Although it seems counterintuitive, smaller lungs can help some people with emphysema breathe more efficiently, says study coauthor Robert A. Wise of Johns Hopkins. Removing damaged tissue, usually 20 to 30 percent of each lung, often enables the remaining tissue to inflate better, he says. Such lung surgery was first tried in the late 1950s but abandoned. More than 30 years later, surgeons performing lung transplants noticed that some patients fared well despite receiving undersized lungs, Wise says. This observation and much-improved postoperative care, revived the surgery. While successes in the 1990s created a flurry of hope, the renewed operations have yielded mixed results overall.

In the new trial, researchers randomly assigned half of 1,218 emphysema patients to receive surgery and standard care and half to get standard care alone. Standard care includes aerosol drugs to open air passages, antibiotics for infections, seasonal flu shots, and an exercise program.

Data released from this study in 2001 indicated that patients undergoing surgery for the most severe emphysema had higher death rates than did such patients getting only standard care (SN: 9/8/01, p. 159).

In the other study volunteers, the death rates in the two groups were roughly equal--about one in four patients--over 29 months, the researchers now report. However, the surgery enabled certain patients, especially those entering the study moderately ill with upper-lung damage, to improve their exercise capacity and quality of life. Patients who began the study with less-severe emphysema "derived less benefit from surgery," Piantadosi says.

The study was "well-designed and well-conducted," says James H. Ware of the Harvard School of Public Health in Boston, writing in the same journal issue. However, the results don't yield a global guideline for physicians deciding whether to advise surgery, he cautions.

Nevertheless, Wise says, the findings "will permit surgeons and patients to have very accurate discussions of what the possible benefits and risks of this surgery are."

The research will also provide a framework for insurance companies and the Medicare program to use in establishing reimbursement criteria for the surgery, Piantadosi says.