Kidney donation after cardiac death may expand donor pool

'Kidney donation after cardiac death may expand donor pool'

Friday, December 7, 2007

WINSTON-SALEM: New research at Wake Forest University Baptist Medical Center suggests that transplanting kidneys from donors who died after cardiac arrest – which used to be considered taboo – offers a promising approach to increase the donor pool, according to Eurekalert, the news service of the American Association for the Advancement of Science.

A study found similar short-term results between kidneys donated after cardiac death (DCD) and kidneys donated after brain death, according to senior researcher Robert Stratta, M.D., a professor of surgery. The results were reported today at the annual meeting of the Southern Surgical Association in Hot Springs, Va.

“Despite greater initial resource utilization, comparable short-term results can be achieved with kidneys donated after cardiac death,” said Stratta. “This alternative provides an important means of increasing the donor pool.”

Originally, all transplanted organs came either from donors who died after cardiac death (so-called non-heartbeating donors) or from living donors. That changed in the 1970s because of new laws defining death as a lack of brain activity. In addition to brain death becoming the standard definition of death for organ donation, DCD organs were no longer used because of the possibility of damage to the kidneys when they were deprived of blood and oxygen.

Because of the current shortage of donated organs, experts in the field are working to make more effective use of organs that are available. In the last decade, median waiting times for kidney transplantation have doubled, and the kidney waiting list has increased nearly threefold. There are currently 78,000 people are on the waiting list for kidney transplantation in the United States. In 2006, only 24 percent of them received transplants.

There is now renewed interest in DCD organs, and transplant centers across the country are beginning to use them. From 2005 to 2006, a 16 percent increase occurred in DCD donors, from 560 to 647 donors. These organs are donated by families who decide to withdraw life support when patients have severe irreversible brain injury and no chance for meaningful recovery. These patients do not meet the criteria for brain death, and will experience cardiac arrest when life support is withdrawn.

Organ recovery occurs only after a declaration of death based on complete cessation of heart activity for a specific period of time. While the use of these organs is becoming more common, it represents less than 10 percent of deceased donor transplant activity in the United States.

The current study involved 53 kidney transplants and four transplants of both a kidney and pancreas that all involved organs donated after cardiac death. The transplants occurred between April 2003 and October 2007. After donation, all kidneys were placed on a pump to resuscitate them and preserve their function. With a mean follow-up of 12 months, survival rates were 95 percent for patients, 88 percent for kidneys, and 100 percent for pancreata that were transplanted.

The researchers compared results of these DCD transplants with 316 transplants involving kidneys donated after brain death that occurred during the same study period. There were no differences in patient survival or survival of the transplanted organs, although one-year kidney function for DCD donor kidneys was intermediate between standard criteria (younger) and expanded criteria (older) brain-dead donors.

Also, in over half (57 percent) of the transplants involving DCD organs, there was delayed graft function, which meant that the recipient required temporary dialysis to support the transplanted kidney before it began functioning on its own. These organs also had higher rates (19 percent versus 10 percent) of acute rejection, which is when the body shows early signs of rejecting the transplanted kidney. These complications resulted in longer hospital stays (11 days for DCD transplants versus 8 days for transplants involved organs donated after brain death.) However, delayed graft function did not result in a higher rate of graft failure as virtually all of these DCD donor kidneys recovered adequately to provide life-sustaining function.

Further study also suggests that the use of extracorporeal support after cardiac arrest and declaration of death, which pumps oxygenated blood throughout the body, may offer an innovative way to reduce delayed graft function and improve organ recovery in DCD donors. In cases where life support is being withdrawn and the family wants to donate organs, the technology is implemented immediately after the patient is declared dead.

In a comparison of 10 kidneys recovered with extracorporal support versus 47 kidneys recovered without the support, rates of delayed draft function were reduced from 60 percent to 20 percent. Moreover, extracorporeal support permitted the use of other organs for transplantation, such as the liver and pancreas.

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