Contrary to accepted wisdom, kidney donations from people whose hearts have stopped beating may, in fact, be just as good as donations from brain-dead organ donors.
That result — released today by the medical journal, Lancet — will come as good news to the tens of thousands of Americans who are currently wait-listed for a kidney transplant, still in need of a donor. The new study was conducted in the U.K., where a severe shortage of organ donors has led to an increase in the proportion of donations coming from people who have undergone cardiac death: from just 3% in 2000, up to 32%, according to figures cited in the Lancet paper. (A different study earlier this year already showed that transplant from a cardiac-death donor is better than no transplant at all.) Now, the new research shows, it seems that recipients of cardiac-death-donor kidneys have identical five-year survival to those patients who received a more traditional transplant organ — at least among first-time transplant recipients. They also have similar estimated glomerular filtration rates — a measure of kidney function.
All of the heart-death donors in the study underwent what the researchers call a “controlled cardiac death.” In most cases this means that the donor had suffered massive irreversible brain damage but did not yet meet clinical criteria for brain death; the donor then died when family members opted to remove life support.
Still, however, a cardiac death puts different strains on the organs than brain death does, so the transplant success was anything but certain. As the study authors explain:
Kidneys from brain-death donors are exposed to substantial metabolic and hormonal disturbances that accompany brain-stem death, whereas kidneys from cardiac death-donors incur a variable period of warm ischaemia [when bodily tissues are still warm, before technicians can cool or preserve the organ, but after blood flow is lost]. Warm ischaemic injury increases the incidence of delayed graft function, suggesting that kidneys from cardiac-death donors are inferior to those from brain-death donors.
The finding, then, that these organs may not be inferior after all comes as something of a surprise. The authors write:
[F]or recipients of their first grafts, kidneys from controlled cardiac-death donors had excellent results.