Head replacement surgery, up to now, still remains at the theoretical level, and has not really been performed on a viable patient, let alone a successful surgery. Head replacement surgery itself is very complicated, because it is necessary to anastomose not only all the blood vessels, but also all the nerves, including the medulla oblongata and spinal cord. It is very difficult to anastomose the medulla oblongata and spinal cord and all the nerves in the first place. It’s almost impossible to do. Secondly, two internal carotid arteries, two venous arteries, and two vertebral arteries, plus the corresponding jugular veins, have to be anastomosed, which makes the surgery even more difficult and almost impossible. Finally, the atlanto-occipital joint has to be reconstructed and the skin sutured.