(CNN) -- You might think that heavy smokers make for bad lung donors. But a new a study finds donors who smoked more than a pack of cigarettes a day for more than 20 years were strong candidates for double lung transplant donors.
The study was presented this week at the annual Society of Thoracic Surgeons meeting.
Authors of the study evaluated 5,900 adult double lung transplants between 2005 and 2011 in the United Network for Organ Sharing (UNOS) database. UNOS is the nation's organ transplant management system. Heavy smokers made up 13%, or 766 of the double lung transplants studied.
Researchers found that the patients who received the smokers' lungs had similar short and medium term survival rates as those who received lungs from people who did not smoke heavily.
Patients who received heavy smokers' lungs tended to stay in the hospital for a few days longer for recovery. However, over a two-year span, researchers found that lung function and death rates in recipients who had received heavy smoking donor lungs was similar to those who received healthier lungs.
As the number of people in need for double lung transplants has grown, doctors have had to expand the donor pool. According to Dr. Sharven Taghavi, lead author of the study and a surgical resident at Temple University, "Historically, these donors were excluded. They were generally considered to be less than ideal."
As Taghavi explained, "Some patients are in a very dire situation. They may not have the time to wait, so they have to use the lungs that are available."
Currently, there are more than 1,600 people waiting for lung transplants, most of them waiting for a year to two years for a set of lungs.
Dr. Marie Budev is director of the Cleveland Clinic's lung and heart transplant program, one of the largest in the country. Budev, who didn't participate in the study, said she wasn't surprised by the outcome. "In practice, we're trying to balance two things --- survival of our patients, and preserving a donor pool."
Because of the link between smoking and lung cancer, donor lungs must be carefully inspected, said Taghavi and Dr. Yoshida Toyoda, a co-author of the study. "We recommend a CT scan for evidence of tumors and emphysema, in addition to routine assessment including blood gas, bronchoscopy, and visual inspection," Toyoda said.
While the results look promising, Tagahvi did say that additional follow-up is needed to see if there is any difference in long-term outcomes.
In addition, he emphasized the importance of informing the patient and family of the circumstances surrounding the lungs. As Toyoda explained, "We need to discuss with potential recipients the possible higher risk of developing lung cancer, and obtain an informed consent specific of heavy smoking history."
"It comes to us asking and informing our patients, with critical data, and saying this is what we know, and what it may mean to you... your risk of malignancy may not be greater. But your risk of rejection won't be more. And your lung function will be maintained over time," said Budev.
As Budev pointed out, the 13% of people in the study who received lungs from heavy smokers in study may not have received any lungs otherwise.