First human head transplant set for December 2017
The world's first human head transplant has been scheduled for December 2017.
Valery Spiridonov, who suffers from Werdnig-Hoffman's, a muscle wasting disease which has left him in a wheelchair, has volunteered for the ground-breaking procedure.
It will performed in China by Italian neuroscientist Sergio Canavero and Xiao-Ping Ren, who has carried out 1,000 head transplants on mice.
The surgery is expected to take at least 36 hours and requires the patient's head and donor body to be cooled down to between 12C and 15C so cells survive longer without oxygen.
The tissue around the patient's neck and spinal cord is then cut and then fused on to the donor body.
Following the operation, Spiridonov will be put into a coma for a month and given drugs to stop his body rejecting the new head.
If successful, Canavero believes the patient would be able to speak in his own voice after waking and that walking could be possible within a year.
The procedure has prompted much controversy with many branding it unethical.
Experts have claimed it is not possible and that instead of being two years away from being successful, it is "more like 100 years".
No one has ever attempted a human head transplant before and attempts on animals have had limited success.
In 1970 Dr Robert White 'successfully' transplanted a head on a monkey but the spinal cord was not attached to its body and it died eight days later.
More recently, Chinese doctor Xiao-Ping Ren conducted head transplants on more than 1,000 mice - but none lived long afterwards.
Russian volunteer Spiridonov said the technology is "similar to the first man to walk in space."
"The operation is aimed at restoring independence to the severely disabled," he said.
"If it is successful, it will help thousands who are in an even more deplorable state than me in the future."