Expanded criteria offer new hope for kidney transplants
Severe shortage leads to use of older organs
Just a few years ago, kidneys in an adult age 60 or older, or in someone age 50 to 59 who had two or more of the following criteria — death from stroke, hypertension, or elevated creatinine — were considered outside the standard criteria for transplantation and went with their owner to the grave.
But recent advances in transplant medicine and success in transplants, coupled with the increasing number of patients in need of kidneys and the scarcity of standard-criteria cadaver kidneys, have opened up a new opportunity for some people to receive kidneys from those donors previously considered marginal, at best. (See table, on right.)
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Expanded Criteria for Cadaver Kidneys
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The use of expanded-criteria kidneys raises new ethical questions, according to Mark Fox, MD, past chairman of the United Network for Organ Sharing (UNOS), the national organ matching system. UNOS operates a 24-hour computerized organ sharing system, matching donated organs to patients registered on the national organ transplant waiting list.
"These [expanded-criteria] kidneys are marked by an increased risk of graft failure," he explains. "But the upside is that patients live longer with transplants than they do on dialysis."
Making that distinction clear to the potential recipient, Fox says, requires careful preparation, disclosure, and informed consent.
Even with failure, patient can live
When balancing the benefits of transplant vs. the heightened risk of graft failure, he says, the outcome, even in graft failure, is not likely to be death, as it likely would be in the case of heart transplant failure, for example.
Expanded-criteria kidneys are offered first to donors who have agreed to accept expanded-criteria organs and for whom the donor kidneys are perfect matches. Next, they’re offered to less perfect matches who agree to expanded-criteria organs, and, finally, they’re offered nationally to prioritized donors on the UNOS waiting list.
Among the many factors to consider are the age of the recipient (an older patient with a shorter life expectancy would be a better potential recipient for an expanded-criteria kidney than a younger patient) and how well the patient is doing or is expected to do on long-term dialysis.
"It’s a challenging question: Who are the ideal candidates to receive these kidneys?" says Fox. "My 20-year-old son who needs a transplant, unless he were in dire straits, I would probably rather he wait for a standard-criteria kidney. But if my 60-year-old father needed one, [an expanded-criteria organ] is probably the right balance."
Kidneys most-needed organ
Kidneys are presently the only organ to which expanded criteria are applied, and UNOS says the serious shortage of cadaver kidneys is one factor driving expanded-criteria organ collections. At the same time, transplantation is beneficial to an increasing number of patients with kidney failure, and the waiting list for kidneys increases by several thousands each year. UNOS projects that more than 4,000 patients will die waiting for a kidney transplant each year.
According to UNOS data, the waiting time for a cadaver kidney is more than four years in most parts of the United States. Many patients are waiting longer because their transplant markers that determine the kidney match may not be very common and keep them from having enough points to get a kidney offer.
The number of people awaiting a kidney transplant in the United States exceeded 60,000 for the first time in 2004, making it by far the most commonly transplanted and most commonly needed organ. Expanded donor kidneys accounted for approximately 11% of the deceased donor kidney transplants performed in 1994, and increased to approximately 16% in 2003. Expanded-criteria kidneys made up 20% of all recovered deceased donor kidneys.
Change for would-be donors
Expanding criteria for donor kidneys has created a whole new pool of potential donors, but because this area of transplant medicine is new to most laypeople, older people and those who have high blood pressure, for example, may think they are not donor candidates.
"Older people might have already thought, I’d like to be an organ donor, but who would want my organs?’" Fox points out. "That’s why it’s so important that if someone would like to be an organ donor, even if he or she thinks their organs would not be suitable, they should let their wishes be known, and then let the professionals in transplant medicine make the decision of whether the organs are suitable."
Educating potential recipients is important, too, Fox says. While people live longer with successful transplants than on dialysis, the risks involved — particularly the risk of organ rejection — need to be thoroughly explained.
"It’s a challenging ethical problem to frame," says Fox. "The downside is not the risk of death so much as it is the return to dialysis [if the transplant fails].
"We know that it’s cheaper and you live longer if you’re off dialysis. You survive longer with a transplant. So it makes more sense to pursue it, but you have to frame it carefully with the recipient."
Sources
- Mark Fox, MD, PhD, Past Chairman, Ethics Committee, UNOS; Assistant Professor, Oklahoma University-Tulsa Health Services Center. E-mail: [email protected].
- United Network for Organ Sharing, 700 N. Fourth St., Richmond, VA 23219. Phone: (804) 782-4800. Web site: www.unos.org.
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