A team of researchers from Germany and the United States has successfully kept the heart of a pig continuously beating inside the body of a baboon for over two years.

Now, experts believe the recent scientific breakthrough could lead the creation of genetically engineered organs that can be used to replace the damaged hearts of cardiac patients.

In a study featured in the journal Nature Communications, scientists from the National Institutes of Health (NIH) made use of genetic engineering to produce pigs' hearts that are more compatible with the immune system of baboons.

For years, organ transplants between different species (xenotransplantation) have been made complicated because of the tendency of the recipient's immune system to reject the new organ.

However, by using organs from a genetically modified pig along with an immune-suppressing drug known as anti-CD40 antibody, the researchers were able to place pigs' hearts inside the bodies of five baboons.

Instead of replacing the hearts of the baboons, the team simply added the new organs into their bodies and hooked them to the primates' circulatory system. This allowed the original baboon hearts to continue pumping blood.

The researchers discovered that not only did the immune system of the baboons did not reject the pigs' hearts, but also the additional organs kept pumping inside the animals' bodies for an average of 945 days. This period was longer than any other time frames previously recorded by the team featuring pig-to-primate heart transplants in the past five years.

The team believes that exposing the baboons to a regimen of the immune-suppressing drug played a key role in preventing the animals' immune system from rejecting the pigs' hearts while also allowing them to pump blood throughout their bodies well.

Muhammad Mohiuddin, a cardiac transplant expert from the NIH's National Heart, Lung, and Blood Institute (NHLBI) and lead author of the study, pointed out that xenotransplantation was used to be considered merely some form of experimentation and that it carried no significant implications.

However, with the results of the new study, Mohiuddin said that people are beginning to learn that cross-species organ transplants can actually work.

The researchers chose pigs for the creation of laboratory-grown organs because of the animals' similarities, both physiologically and genetically, to humans.

The growing demand for available organ donations has led researchers into developing ways to make xenotransplantations safer and more effective for patients.