Human kidney kept alive on machine for 24 hours

August 25, 2001

For the first time, a human organ, a kidney, has been kept "alive" -- functioning in the same manner it did in the body of the donor -- for almost 24 hours in a device at the University of Chicago Hospitals.

The machine, called POPS for Portable Organ Preservation System, keeps organs in a warm, blood-based, oxygenated, nutrient solution. Currently, solid organs for transplant are removed from donors and put on ice -- maintained at 4ºC -- until they can be transplanted. Cellular activity is slowed by cooling and metabolic function diminishes. Time in the cold is hard on the organs and they must be used as quickly as possible to minimize damage. In addition, when the cold organ is re-prefused with warm blood, it resists the process and may sustain more damage.

David Cronin, MD, assistant professor of surgery at the University of Chicago, and a team of investigators are working with biotech company TransMedics of Woburn, Massachusetts, to develop the device, which is designed to preserve solid organs for transplant without the need to "ice" them.

"This could transform the way transplants are performed," said Cronin. "POPS could make it possible to keep organs undamaged for much longer periods of time. We would have more time to properly prepare both the patient and the organ for transplant surgery."

The machine is intended for use with all organs that are currently used in transplant, including heart, kidneys, lungs and hearts. Cronin has been involved in the design of the POPS system for the past three years. More than 500 animal organs, including hearts, kidneys and livers, have been tested on the machine in the last one and a half years.

On Saturday, August 25, 2001, the University of Chicago team removed the first human kidney tested in POPS at the end of 24 hours. They are analyzing data on the functioning of the kidney while it was in the system and examining the kidney itself in detail to see how it fared.

So far it appears to have behaved exactly like a kidney in a human body. As blood is pumped through it, in a way that mimics the heart's pumping, that blood is filtered and the kidney makes urine as it would normally. The animal organs that have been tested have all behaved normally.

"We are currently forced to maintain a very high bar for organs used in transplant," said Cronin. "A patient receiving a heart or liver that doesn't function may not get a second chance. This system, in addition to giving us time, allows us to see that the organ is functioning and perhaps even repair it. This technology could expand the range of usable organs and save lives."

Other university centers involved in the development of this technology include Kings College, University of Leicester, University of Pittsburgh and Edmonton University.