杏吧原创

ORGAN transplants may seem almost routine procedures nowadays, but they remain mired in anxieties and ethical challenges.

The number of people needing a new organ vastly outweighs the supply, because less than 1 per cent of all deaths take place in a manner that makes organ donation medically possible.

That鈥檚 why some doctors are now seeking ways to allow more dying patients become donors, even challenging long-held ethical principles about the boundary between life and death. Others say the methods being explored go too far, and could jeopardise organ donation all together.

After all, most transplants happen only when a family, in the middle of what is often a sudden and untimely bereavement, consent to their loved one鈥檚 body being treated in ways that could be seen as unnatural and brutal. Is it ethical to push such families further, if it could save lives?

鈥淲hat we are doing is terribly important. But people are worried that families will get upset鈥�

鈥淲hat we are doing is terribly important. But people are worried that families will get upset,鈥� says of Papworth Hospital in Cambridge, UK.

For most of human history, life ended when the heart stopped beating. That still applies to the majority of deaths, but as intensive care progressed in the mid-20th century, a new definition evolved: brain death.

It applies to just a few people who end up in a strange twilight zone, often after a head injury or lack of oxygen. Their heart still beats; but their injuries have caused catastrophic and irreversible brain damage. They effectively have no brain function, which can be confirmed with some simple tests.

These people cannot breathe for themselves 鈥� only the rhythmic actions of a ventilator pushing air into their lungs keeps their blood supplied with oxygen. Legally this is the equivalent of being 鈥渢raditionally鈥� dead. Usually, once the tests are done and goodbyes have been said, the ventilator is turned off and within minutes the lack of oxygen stops the heart too.

People certified as brain-dead have, with their family鈥檚 permission, been the source of most transplant organs for many decades 鈥� with the exception of organs that can be safely taken from live donors such as single kidneys and small parts of the liver. Crucially, with donors who are brain-dead, ventilation isn鈥檛 turned off until the middle of surgery, keeping their organs well oxygenated and better prepared for transplant.

But as so few lives end in brain death, transplant surgeons needed to expand the donor pool. In the 1990s, they began considering people who were also dying from irreversible brain damage, often from physical trauma or a stroke, but who were not brain-dead.

Unlike the previous group, surgeons cannot start to retrieve their organs before the ventilator is turned off because they aren鈥檛 yet dead. Instead, doctors have to withdraw ventilation and wait for the heart to stop. Then they wait for an extra period of time 鈥� in the UK it is 5 minutes, in some US hospitals it is less 鈥� and only then do the surgeons begin their work.

Using this group of patients, known as non-heart-beating donors, has raised the number of organs available for transplant by as much as 25 per cent in some hospitals. But hearts from such people aren鈥檛 usable, because these organs are particularly vulnerable to the lack of oxygen in the period between the ventilator being switched off and the organ being transplanted.

Restart the heart

So, for the past two years, Large鈥檚 team has been doing something not done anywhere else in the world. After a donor is declared dead, they restart the heart while it is still in the body. In effect, they use the donor鈥檚 body as an incubator, preserving the heart and other organs.

The team doesn鈥檛 jolt the heart back to life with electricity. Instead, they hook the body鈥檚 circulation to a machine that pumps and oxygenates the blood, setting the heart beating again. An artery is blocked off to stop blood reaching the brain, both to prevent harmful substances from the damaged brain entering the blood, and to reassure families that their relative won鈥檛 wake up 鈥� although Large says that could never happen anyway because of the severity of the brain damage.

Some have reservations. Many people instinctively see death as when the heart stops 鈥� if it is restarted, will people understand that their loved one has not come back to life?

鈥淭he whole rationale of declaring a person dead is that absence of circulation is permanent 鈥� here you鈥檙e restoring it,鈥� says of the Geisel School of Medicine at Dartmouth in New Hampshire.

The heart-restarting technique works. Since 2015, heart transplants have increased by 15 per cent in the three hospitals where it was approved to take place by NHS Blood and Transplant, the UK body that oversees organ donation. Permission is always sought from the families. 鈥淎s long as people are happy with the idea of this happening to their relatives so they can be the best possible donor, I think it makes sense,鈥� says ,of Newcastle University in the UK.

In the US, restarting the heart while it is in the donor鈥檚 body is seen as too controversial. But a few doctors there have proposed a step that is more radical still. It stems from a potential problem with non-heart-beating donors. Transplant surgery often has to be called off, because the potential donor takes too long to die after the ventilator is withdrawn. They continue breathing unevenly for many hours before their heart finally stops and the long period of low oxygen levels leaves their major organs unusable.

This could be avoided by taking the patient鈥檚 organs while they are still alive, under a general anaesthetic. But it would be a clear breach of the 鈥渄ead donor rule鈥�, that no one鈥檚 death may ever be caused by taking their organs (see 鈥�Living donors鈥�).

Bernat thinks this idea risks losing public support for the whole concept of organ transplants. He says some families already mistakenly suspect hospitals of being more interested in their relative鈥檚 organs than in saving their life. As a neurologist who has cared for many patients with brain injuries, he has heard this directly from some families, he says.

鈥淥rgan donation may be the last wish of the donor. If so, we have a moral duty to try to realise it鈥�

Such live donor transplants haven鈥檛 taken place, but of Boston Children鈥檚 Hospital, who is one of those , says it could help bereaved families.

He recalls one such case involving an 8-year-old girl, who was severely brain-damaged from suffocation in a freak accident. Her family chose to donate her organs, but after ventilation was stopped, she took too long to die for her organs to be usable, adding to her family鈥檚 distress.

鈥淭his was almost a secondary loss for her family,鈥� Truog says. 鈥淗er father said: 鈥業 just don鈥檛 understand why we could not have given her an anaesthetic to make sure she saves the lives of other children鈥�.鈥�

At the moment there are no signs of a change in the rules to allow donation under anaesthetic, but the fact that doctors are debating it in journals and at conferences suggests opinions may one day change.

In the UK, the approach of restarting the heart in the body remains a pilot scheme while public reactions and the medical results are assessed. 鈥淭o date, families have had no problem with Papworth protocol,鈥� says Paul Murphy of NHS Blood and Transplant. 鈥淚ndeed, knowledge that the heart is likely to be used for transplantation becomes very important for them.鈥�

An initial analysis suggests the hearts , although longer-term follow-up is still needed.

For Large, there鈥檚 another benefit of pushing boundaries in this way 鈥� it鈥檚 to do what the dying patient would have wanted. 鈥淥rgan donation may be the last wish of the donor,鈥� he says. 鈥淲hen that鈥檚 the case, we have a moral duty to try to realise it.鈥�

This article appeared in print under the headline 鈥淒ying to save a life鈥�