A stuffed ‘two-headed’ dog is exhibited in the collection of the Biological Museum and represents the first experiment on transplantation of the entire complex of organs. The surgery was performed by Vladimir Demikhov, Doctor of Biological Sciences and one of the pioneers of transplantology.

The scientist started designing the concept of organs transplantation back in the 1940s. In 1946, Demikhov became the first person who successfully transplanted the second heart to a dog and then managed to replace the cardiopulmonary complex. In 1948, he started his experiments with liver transplantation and later managed to replace a dog’s heart with a donor’s one, which proved the possibility to perform such surgeries on humans. Demikhov in fact faced a significant problem which was the immune incompatibility of donor and recipient.

In 1954, the scientist integrated circulatory systems of an adult dog and a puppy after removing its heart and lungs. The next day after the surgery, the puppy woke up when the effect of anesthesia was over. According to the way it looked at others, the puppy was conscious; it could turn its head, lick its lips at the sight of a saucer of milk, and even bite others.

Soon, immune incompatibility provoked rejection of the transplanted organs. The protein set of the puppy did not match the one of the recipient dog and antibodies were produced in its blood that rejected foreign tissue. In five out of twenty similar experiments, animals with integrated organs complexes lived from six to seven days, and there was only one case when they managed to live for 29 days.

That set of experiments sparked studying and using immunodepressants, the medical product which suppresses the immune response of the recipient. Nowadays, there are no transplantation surgeries conducted without them, since even careful donor matching does not guarantee the success of the procedure.

The use of immunosuppressants greatly improves the chances of donor tissue engraftment. However, the very first heart transplantation surgery using immunodepressants ended in the patient’s death. It was performed by Christian Barnard, a South African surgeon, who considered Demikhov to be his teacher. The patient got a new heart after five-hour surgery, lived only 18 days, and died because of bilateral pneumonia caused by suppression of the immune system.