• A team of surgeons at NYU Langone Health have performed two successful xenotransplantations of heart pigs into humans
• Both of the patients were clinically brain dead, allowing for doctors to undergo the risky experiment
• In both cases the hearts immediately started to work without the need of machinery to assist them, a first for this type of transplant
• The trials only lasted three days each, though, and there is no data as to how these types of transplants will be successful long-term 

Doctors have made a break through in the practice of xenotransplantation after successfully importing two genetically engineered pig hearts into human bodies.

the person's body did not reject the heart and the pigs' hearts operated as normal without the need of any machinery - unlike previous patients that experimented with similar transplants.

While the process of xenotransplantation - moving an organ from one species to another - is still in its early stages experts are hopeful that these types of breakthroughs will help close a shortage of available organs around the world, especially for children.

Our goal is to integrate the practices used in a typical, everyday heart transplant, only with a nonhuman organ that will function normally without additional aid from untested devices or medicines,' said Dr Nader Moazami, director of heart transplantation at NYU said in a statement. 

'We seek to confirm that clinical trials can move ahead using this new supply of organs with the tried-and-true transplant practices we have perfected.'

The transplants were carried out on two patients that were already considered medically deceased.

Their status makes them valuable to researchers as it allows them to perform experiments that may be too risky for a living subject, but on a person whose bodily operations are still somewhat functional.