TUESDAY, Jan. 18 (HealthDay News) -- Kidneys from live donors that are transported across town or across the country are as safe to use in transplants as a kidney from a donor in the same hospital as the recipient, says a new study.

Researchers followed up on 56 kidneys from live donors that were exchanged among 30 transplant centers in the United States and Canada. All of the transplanted organs survived and quickly began making urine and clearing creatinine out of the recipients' bodies.

The kidneys in the study were kept on ice and traveled an average distance of 792 miles, with a range of less than one mile to 2,570 miles. On average, the organs spent 7.6 hours outside the body, with a range of 2.5 to 14.5 hours. About 87 percent of the kidneys were transported by air and 13 percent by motor vehicle.

"There was no difference in how well the kidneys functioned compared to those transplanted immediately from someone in a nearby operating room in the same hospital," Dr. Dorry L. Segev, an associate professor of surgery at the Johns Hopkins University School of Medicine, said in a Hopkins news release.

The study was published online Jan. 10 in the American Journal of Transplantation.

The researchers said their findings support the growing practice of kidney exchanges, in which an incompatible donor gives a kidney on a loved one's behalf so that person can get a compatible kidney from another donor in return.

"As the national system expands, shipping kidneys will become more and more necessary," Segev said. "Kidney exchanges have gone from being something you do at your own center to something done by working together nationwide. And now we know kidneys can be safely transported anywhere."

More information

The National Kidney Foundation has more about kidney transplant.