The controversial case of three infant heart transplants performed at a hospital in Denver, USA, has stirred an ethical and legal debate, with one expert suggesting that the criteria used to obtain the organs were not strictly within the law as it applies to the definition of donor death.
The transplants are described in a study by Mark Boucek, the surgeon who led the Denver team, and colleagues, in the August 14 issue of the New England Journal of Medicine, NEJM, where it is accompanied by three other papers and a video round table discussion that debate the ethical and legal issues raised.
Since 2004, Boucek and his team at Denver Children’s Hospital have carried out three heart transplants where the the hearts were harvested from babies whose parents gave consent for them to be taken off life support because they were badly brain damaged. The law permits hearts to be taken from patients who are declared brain dead, but in this case they were not. The other way you can legally take hearts from donors is if death is due to irreversible cardiac death, that is the heart has stopped beating and there is no chance of restoring its function.
The Denver doctors waited for 3 minutes after the heart had stopped in the case of the first transplant performed in 2004, and for 75 seconds in the case of the other two transplants, performed in 2007. The recipients, who were all very young infants at the time, are alive and well today.
A casual observer might ask, what is wrong with that? The parents gave consent, the donors were dead because their hearts had stopped, and the recipients’ lives were saved. The debate that has been stirred up appears to hinge on two points: (1) how long should you wait after a heart has stopped beating before you remove it from the donor, and (2) how can you use the irreversible cardiac death criteria to declare a donor dead if you can then successfully revive the heart in another body?
Boucek and colleagues’ actions have caused controversy because they took the waiting time from heart stopping to heart removal under the 2 minutes used by some doctors and considerably less than the 5 minutes recommended in guidelines set by the non profit organization The Institute of Medicine (IOM).
The reason the IOM set the threshold at 5 minutes was to make sure the heart did not start beating again on its own. However, some doctors use the 120 seconds threshold because the earlier you remove the heart, the greater the chances of a successful transplant because there is a reduced risk of tissue damage from lack of oxygen.
In their article Boucek and colleagues said there was no published evidence of hearts starting by themselves after 60 seconds.
In an accompanying commentary, Robert Veatch, a professor of medical ethics at Georgetown University, said this was not the point. The point was that once you move from brain death to irreversible cardiac death as the cause of the donor’s death, then you have to take into account the possibility of reactivating the heart artificially. And, since in these cases it was possible to do that (as proved by the fact the heart was reactivated albeit in a different body), you can’t use irreversible cardiac death as the cause of death of the donor.
In fact Veatch argued that “under current law, it is not possible to procure a transplantable heart after cardiac death”, and suggested that what happened in these cases was “ending a life by organ removal”.
There are two ways around this, said Veatch, and both involve changes to the law. First you could permit removal of organs before the donor is dead, and some theorists have argued for this, for instance in cases of terminal illness and where donors give consent for their lives to be stopped via organ removal. Veatch said this kind of change would be “practically and morally implausible”.
The second way would be to change the brain dead definition of death to include stoppage only of those functions that control consciousness, what has been called the “higher brain” definition of death. This definition is favoured by as many as one in three Americans on religious and philosophical grounds, said Veatch.
“But,” wrote Veatch, “whether or not any such legal changes come to pass, any successfully transplanted heart cannot have come from a person who was declared dead on the basis of irreversible stoppage of the heart”.
Nevertheless, according to a report in the Wall Street Journal (WSJ), some experts have said other transplant centers are likely to follow the Denver team’s lead. According to their figures, about 50 babies a year die while on a waiting list for a new heart, and there are many more who need a transplant who are not on a list.
Jonathan Chen, the director of pediatric cardiac surgery at New York Presbyterian Hospital, told the WSJ that he found the three cases at Denver “really amazing” and thinks other major medical centers will “absolutely” try similar approaches, although many will also wait for more evidence to emerge before going down that route.
But James Bernat, a neurologist at Dartmouth Medical School, told the paper that he doubted the transplant community would favour reducing the waiting time between organ death and harvesting to 75 seconds. He said there was not enough evidence to support the view that the donor is truly dead after such a short period of time and that the heart will not spontaneously start beating again.
“Pediatric Heart Transplantation after Declaration of Cardiocirculatory Death.”
Boucek, Mark M., Mashburn, Christine, Dunn, Susan M., Frizell, Rebecca, Edwards, Leah, Pietra, Biagio, Campbell, David, the Denver Children’s Pediatric Heart Transplant Team.
N Engl J Med 2008 359: 709-714.
“Donating Hearts after Cardiac Death — Reversing the Irreversible.”
Veatch, Robert M.
N Engl J Med 2008 359: 672-673.
Sources: NEJM, Associated Press, Wall Street Journal.
Written by: Catharine Paddock, PhD