Researchers try new ways of preserving more hearts for transplants

Washington – Two university hospitals are pioneers in new ways of expanding vital heart transplants for adults and babies – progress that could help recover potential heart donations which are too often unused.

The new research aims to overcome the obstacles to the use of someone who dies when her heart stops. Called DCD or donation after circulatory death, it involves a controversial recovery technique or the use of expensive machines.

Duke and Vanderbilt university surgeons reported on Wednesday that they had designed easier approaches separately to recover these hearts. In the New England Journal of Medicine, they successfully described the transplantation of hearts to a 3 -month -old child in Duke and three men in Vanderbilt.

“These DCD hearts work as well as the hearts of dead brain donors,” said Dr. Aaron Mr. Williams, principal author of Vanderbilt.

Most transplanted hearts come from dead brain donors. In these situations, the body is left on a fan that continues to beat the heart until the organs are removed.

Circulatory death occurs when someone has a non -urviable cerebral lesion, but because the whole function of the brain has not stopped, the family decides to withdraw the support of life and the heart stops. This means that the organs can spend a certain time without oxygen before being recovered, a temporal lag generally feasible for kidneys and other organs, but this can raise questions about the quality of hearts.

To counter damage and determine if the DCD organs can be used, surgeons can pump blood and oxygen with the abdominal organs and deceased donor’s chest – after tightening the brain. But it is ethically controversial to artificially restore traffic temporarily and certain hospitals prohibit this technique, called normothermal regional infusion, or NRP.

Another option is to “revive” the DCD organs in a machine that pumps blood and nutrients on the way to the transplantation hospital. The machines are expensive and complex, and Dr. Joseph Turek de Duke said that the devices could not be used for young children’s hearts – the age group with the most disastrous need.

The Turek team has found common ground: to remove the heart and fix certain oxygen and blood tubes to briefly assess its ability to operate – not in a machine but on a sterile table in the operating room.

They practiced with piglets. Then came the real test. In another hospital, the support of life was about to be withdrawn from a 1 month old child whose family wanted to donate – and who would be a good match for a 3 -month Duke patient in a desperate need of a new heart. The other hospital did not allow the controversial NRP recovery technique, but let the Turek team test the experimental alternative.

It only took five minutes to say that “the coronary arteries fill well, it’s pink, it beats,” said Turek. The team quickly put the little heart on the ice and pushed it back to Duke.

The Vanderbilt system is even simpler: infuse the heart with a cold nutrient solution rich in nutrients before removing it from the body of the donor, similar to the way the hearts of the dead donors of the brain are manipulated.

This “reconstitutes the nutrients that are exhausted during the death process and helps to protect it for transport,” said Williams, adding that Vanderbilt has carried out around 25 transplants of this type so far. “Our point of view is that you don’t necessarily need to revive the heart.”

There is a huge need for more transplanable hearts. Hundreds of thousands of adults suffer from advanced heart failure, but many are not even offered transplants due to organ shortage.

Each year, around 700 children in the United States are added to the transplantation list for a new heart and around 20% pending. Turek said infants are particularly at risk.

Last year, people whose life ended with circulatory death represented 43% of the deceased donors in the country – but only 793 of the 4,572 cardiac transplantations.

This is why many specialists say that finding ways to use more of these hearts is crucial. The new studies are small and at an early but promising stage, said Brendan Parent of Nyu Langone Health, who directs the ethics of transplantation and political research.

“Innovation to find ways to recover the organs successfully after circulatory death is essential to reduce organ shortage,” he said.

If alternatives take place, “I absolutely think that heart programs will be delighted, especially in hospitals that have rejected the NRP.”

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