Sharon Kirkey -
The procedure raises serious ethical concerns, starting with the post-mortem reversal of what was supposed to be permanent: circulatory death.© Provided by National Post
Canada’s transplant community is preparing for the “anticipated adoption” of a novel method of procuring organs that involves restoring warm blood flow to vital organs, even restarting the heart, moments after the donor has been declared dead.
The procedure, known as normothermic regional perfusion (NRP) is already legal in some jurisdictions, outlawed in others and has medical ethicists split over whether it invalidates the declaration of death and violates the dead donor rule, which holds that organs should only be taken from dead patients.
Although not yet used in Canada, researchers have begun searching the literature on NRP’s ethical implications and conducting in-depth interviews and focus groups with organ recipients, deceased organ donors’ families, donation agencies and transplant surgeons, nurses and other health professionals directly involved in the donation process.
“There is growing interest in adopting NRP in Canada,” the team writes in the journal BMJ Open . “Knowing how stakeholder perspectives on NRP could impact trust in donation will allow for the development of policy that responds to these perspectives.”
Organs were once only ever removed from donors declared brain dead, which is defined as the complete and irreversible loss of all brain function. They’re medically and legally dead, but their hearts are still beating. A ventilator keeps oxygen flowing to the heart and other organs until they can be retrieved for transplant.
In 2006, doctors began removing organs from “controlled circulatory death” donors, people who aren’t brain dead but whose prospects for recovery are so grim a decision is made to withdraw life support.
Life support is removed and, after the heart stops and surgeons wait an obligatory five-minute “no touch” period to ensure the heart has permanently ceased beating, organ procurement can begin.
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The difficulty is that the heart and other organs are starved of oxygen and nutrients during the dying process and the mandated waiting period. The heart is especially sensitive to warm ischemia time, time without blood flow and oxygen. Organs can become unsuitable for transplant or take longer to recover once put inside the recipient than they would have “if they’d been getting blood flow the whole time,” said Toronto nephrologist Dr. Jeffrey Schiff, president of the Canadian Society of Transplantation.
With NRP, once death is declared, the major arteries supplying blood to the brain are clamped and tied off. The donor is quickly connected, via cannulas placed inside large blood vessels, to a machine that funnels their blood into a device that adds oxygen and removes carbon dioxide before pumping it back into the body. The goal is to reverse damage to the organs and improve their function.
It’s called “regional” perfusion, because doctors can restore circulation to the abdomen only, if the target organs are abdominal ones like the kidneys, liver and pancreas. More ethically sticky is thoraco-abdominal NRP, which also resuscitates the heart.
The body is perfused for about 60 minutes and then weaned from the pump, allowing doctors to assess the viability of the heart while it’s beating inside the body.
The procedure raises ethical concerns, starting with the post-mortem reversal of what was supposed to be permanent: circulatory death.
“We know that, after about 30 minutes of having someone on an NRP pump, their heart will actually start beating again, spontaneously, to the degree that the pump can be turned off,” said Dr. Charles Weijer, a professor of medicine and philosophy at Western University.
The American College of Physicians, which wants the use of NRP to be paused, argues that by restarting circulation, even artificially, NRP undermines the validity of the definition of circulatory death because “the patient is, in fact, successfully resuscitated.”
Critics also say NRP challenges the dead donor rule, which holds that donors can’t be made dead to obtain their organs and that organ retrieval can’t cause death. By cutting off blood flow to the brain, the doctors’ college argues, “the patient is now dead by brain death criteria — due to actions taken by the physicians procuring the organs.”
Dr. Charles Weijer, a professor of medicine and philosophy at Western University, is helping lead a study on ethical issues posed by a new organ retrieval procedure.© Western University/File
A suddenly spontaneously beating heart isn’t the only ethical quagmire: Writing in BMJ Open, Weijer and colleagues said uncertainty exists over whether the surgical techniques used to prevent brain reperfusion can absolutely rule out any collateral blood flow to the brain. “Reanimation of the donor’s brain may result in harm to the donor should they regain sentience,” they said.
It’s unclear what degree of brain blood flow would be needed to restore awareness. “Potentially — it’s pretty unlikely we think — potentially there could be restoration of brain activity, or even brain function,” Weijer said.
“And the concern there is, of course, if brain function is restored to the point where someone becomes conscious, they might be capable of experiencing pain, and that obviously would be a serious threat to donor safety.”
Weijer sees significant ethical barriers to using NRP to restart hearts. “I think prudence demands that we start with abdominal.” In a separate commentary published last year, he and his colleagues in critical care and transplant medicine also called for continuous brain monitoring during NRP to exclude “brain reanimation.”
With abdominal NRP, there’s less likely to be any flow of oxygenated blood above the diaphragm. Circulation is also limited to the abdomen, so the heart doesn’t start beating again.
In the U.S., more transplant centres are incorporating NRP, some without obtaining specific informed consent from donors or their families. It’s permitted in the United Kingdom and Spain but prohibited in Australia. Some ethicists have argued that circulation isn’t restored with the intent to resuscitate or “revive” the dead, but only to perfuse organs. “During NRP, the deceased body is ethically manipulated using technology to permit organ recovery, but the body remains dead,” NYU bioethicist Arthur Caplan and colleagues wrote in the American Journal of Transplantation.
Regarding how much families should be told, “informed consent is not just dumping all details on grieving traumatized families,” they wrote. “It requires giving morally relevant information in a sensitive and respectful manner.
“The technique details of standard deceased organ recovery are not shared with families. Whether families want to know, or need to know, specific NRP techniques, is not known. This should be studied.”
Others have argued that if there’s no brain blood flow, the person is dead, whether or not circulation has been restored to other vital organs.
NRP has “enormous potential,” Weijer and his colleagues wrote, by increasing the number and quality of organs available for life-saving transplants.
But trust is the bedrock of Canada’s organ donation system, Weijer said. “The system just does not work without that public trust” and anything perceived as unethical could undermine that trust, he said. “I think we’d also need rigorous studies of donor safety.”
“People are saying this may be something, but only if we can do it in a safe and appropriate way,” said Schiff. “The outcome here is not certain.”
