The heart from the organ donor has been restarted outside the body - the technique offers a new source of organs

Modern heart regeneration procedures for transplantation are ethical or expensive.

Surgeons have developed two inexpensive methods to revive the hearts of people who want to donate their organs after death. The methods have been tested on only a small number of people, but they avoid ethical problems sometimes associated with modern transplantation methods.

Using one of the methods, surgeons were allowed to remove the heart of a child who was declared dead, restart it and transplant it to another child. The method described today in the New England Journal of Medicine (NEJM) can increase the number of hearts available for organ donation, especially for children. About 500 children a year in the United States receive a new heart, but many will die waiting for it.

In the second method, which was also reported today in NEJM2, the researchers were able to freeze and preserve the hearts of adults inside the bodies of their donors, and then successfully transplant them. Participating surgeons say that this procedure can also be used in children.

"These two methods represent important new advances" in acquiring hearts from some donors because they bypass the ethical problems of existing methods," says Robert Montgomery, transplant surgeon at New York University (NYU) in New York.

Current problems

Most of the donated hearts come from people who have been declared dead brains, but whose heart is still beating. However, such cases are not enough to meet the demand for donor hearts.

In some cases, hearts can be obtained from donors who are declared dead after their heart has stopped beating for five minutes - for example, when a family decides to withdraw life support for a person.

For these hearts to be suitable for transplantation, surgeons usually have to either remove the organ from the body and restart it on the machine, or make it beat again while still inside the body. But the first option is expensive and cannot be used for donors weighing less than 40 kilograms, which excludes infants and most children, and the second is not widely used due to potential ethical problems.

The main ethical problem raised by doctors is that starting the heart while it is still in the body may require a change in the registered cause of death, from blood-circulated death to brain death. Another problem is that the procedure can theoretically restore blood flow to the brain, although clamps are used to block this result.

Reviving tiny hearts

To avoid these potential problems, Joseph Turek, a pediatric cardiac surgeon at Duke University in Durham, North Carolina, and his colleagues developed a system to revive children's hearts outside the body. This includes pumping oxygen-saturated blood into the heart through a tube attached to the aorta. Then the blood flows out of the heart through the ventilation hole in the left ventricle, is collected in a bag for re-oxygenation, and then pumped back into the heart.

The team tested the procedure on 12-week-old piglets before the first human test earlier this year. In this case, the surgeons removed the heart of the deceased one-month-old baby, restarted it outside the body, and then transplanted it to a three-month-old baby.

Surgeons have developed two inexpensive methods to revive the hearts of people who want to donate their organs after death. The methods have been tested on only a small number of people, but they avoid ethical problems sometimes associated with modern transplantation methods.

Using one of the methods, surgeons were allowed to remove the heart of a child who was declared dead, restart it and transplant it to another child. The method described today in the New England Journal of Medicine (NEJM) can increase the number of hearts available for organ donation, especially for children. About 500 children a year in the United States receive a new heart, but many will die waiting for it.

In the second method, which was also reported today in NEJM2, the researchers were able to freeze and preserve the hearts of adults inside the bodies of their donors, and then successfully transplant them. Participating surgeons say that this procedure can also be used in children.

"These two methods represent important new advances" in acquiring hearts from some donors because they bypass the ethical problems of existing methods," says Robert Montgomery, transplant surgeon at New York University (NYU) in New York.

Current problems

Most of the donated hearts come from people who have been declared dead brains, but whose heart is still beating. However, such cases are not enough to meet the demand for donor hearts.

In some cases, hearts can be obtained from donors who are declared dead after their heart has stopped beating for five minutes - for example, when a family decides to withdraw life support for a person.

For these hearts to be suitable for transplantation, surgeons usually have to either remove the organ from the body and restart it on the machine, or make it beat again while still inside the body. But the first option is expensive and cannot be used for donors weighing less than 40 kilograms, which excludes infants and most children, and the second is not widely used due to potential ethical problems.

The main ethical problem raised by doctors is that starting the heart while it is still in the body may require a change in the registered cause of death, from blood-circulated death to brain death. Another problem is that the procedure can theoretically restore blood flow to the brain, although clamps are used to block this result.

Reviving tiny hearts

To avoid these potential problems, Joseph Turk, a pediatric cardiac surgeon at Duke University in Durham, North Carolina, and his colleagues developed a system to revive children's hearts outside the body1. This includes pumping oxygen-saturated blood into the heart through a tube attached to the aorta. Then the blood flows out of the heart through the ventilation hole in the left ventricle, is collected in a bag for re-oxygenation, and then pumped back into the heart.

The team tested the procedure on 12-week-old piglets before the first human test earlier this year. In this case, the surgeons removed the heart of the deceased one-month-old baby, restarted it outside the body, and then transplanted it to a three-month-old baby.

According to the NEJM report, three months later, the recipient's heart continued to function normally without signs of rejection. The procedure can lead to another 100 children's heart transplants per year in the United States, says Turek. It also offers an economical alternative to the out-of-body revival of adult hearts, he adds, because it does not require equipment that can cost tens of thousands of dollars.

"This is something worth studying" in more cases, says John Trahanas, a cardiac surgeon at Vanderbilt University Medical Center in Nashville, Tennessee.

Relaxed state

Trakhanas was part of the team that developed the second technique. This procedure includes clamping the aorta of a deceased person, and then filling the heart with a cool oxygen liquid, which keeps it in a relaxed state without resuscitation. The liquid contains a mixture of red blood cells, protective solution, electrolytes and multivitamins. Then the heart is surgically removed and transplanted.

The procedure was successful for the first three adult recipients. The recipients were between the ages of 40 and 60 and still have functioning hearts with no signs of rejection six months after surgery, as described in the NEJM report. Trakhanas says that since then he and his colleagues have conducted the procedure on 20 people with positive results.

Montgomery says that both methods should be replicated in more people to test the results and make sure that heart donors provide good blood supply and heart function.