London, Mar 1: The world's first human head transplant could take place within the next two years, according to an Italian surgeon who claims to have developed a technique for the radical surgery.
Sergio Canavero, from the Turin Advanced Neuromodulation Group in Italy, who first proposed the idea in 2013, has published a summary of the technique he believes will allow doctors to transplant a head onto a new body.
The technique, published in the journal Surgical Neurology International, involves cooling the recipient's head and the donor body to extend the time their cells can survive without oxygen.
The tissue around the neck is dissected and the major blood vessels are linked using tiny tubes, before the spinal cords of each person are cut. Cleanly severing the cords is key, said Canavero.
The recipient's head is then moved onto the donor body and the two ends of the spinal cord - which resemble two densely packed bundles of spaghetti - are fused together.
To achieve this, Canavero intends to flush the area with a chemical called polyethylene glycol, and follow up with several hours of injections of the same stuff.
Just like hot water makes dry spaghetti stick together, polyethylene glycol encourages the fat in cell membranes to mesh, 'New Scientist' reported.
Next, the muscles and blood supply would be sutured and the recipient kept in a coma for three or four weeks to prevent movement. Implanted electrodes would provide regular electrical stimulation to the spinal cord, because research suggests this can strengthen new nerve connections.
When the recipient wakes up, Canavero said they would be able to move and feel their face and would speak with the same voice. He said that physiotherapy would enable the person to walk within a year.
Several people have already volunteered to get a new body, he said. The trickiest part will be getting the spinal cords to fuse. Polyethylene glycol has been shown to prompt the growth of spinal cord nerves in animals, and Canavero intends to use brain-dead organ donors to test the technique.
Canavero aims to use the surgery to extend the lives of people whose muscles and nerves have degenerated or whose organs are riddled with cancer.
Canavero plans to announce the project at the annual conference of the American Academy of Neurological and Orthopaedic Surgeons (AANOS) in Annapolis, Maryland, in June.