While it seems like something out of a science fiction movie, one prominent surgeon believes human head transplants could soon be possible.
Much like Frankenstein, heads could be surgically removed and reattached to another body.
Dr. Sergio Canavero, of the Turin Advanced Neuromodulation Group, estimates that the operation would take 100 surgeons up to 36 hours and would cost £8.5 million.
The procedure has already been successfully done on a monkey in 2001.
Doctors in the U.S. carried out a similar operation to the one in 1970, where a rhesus monkey's head was reattached to another's body.
Though the monkey was able to smell, open its eyes and taste food, it wasn't able to move around as it was paralyzed. It died a few hours later.
But Canavero believes advancements in cell and nerve research could lead to the possibility of successfully reconnecting spinal cords.
"The greatest technical hurdle in cephalosomatic linkage [head transplant] is of course the reconnection of the donor's and recipients spinal cords," Canavero said. "It is my contention that the technology only now exists for such linkage."
In the procedure, the patient would be put to sleep and the head would be removed and cooled to between 12 degrees and 15 degrees celsius.
Surgeons would have one hour to remove both heads and reconnect the transplant head to the circulatory system of the donor body, as the human brain can't survive without a steady flow of blood and oxygen for longer than an hour.
Canavero said the spinal cord would have to be cut with a sharp scalpel and then "mechanically connected" to the other body for it to be successful.
"It is this 'clean cut' [which is] the key to spinal cord fusion, in that it allows proximally severed axons to be 'fused' with their distal counterparts," Canavero said.
Though a head to body spinal connection has not been attempted yet, Canavero said there have been studies where scientists were able to reconnect a spinal cord to a rat.
There have also been studies where polyethylene glycol (PEG) was used to reconnect a severed spinal cord in dogs.