Transplanting one person’s head onto the body of another might sound like a scene from a low-budget horror movie. But Italian neuroscientist Sergio Canavero argues that, with appropriate resources, the procedure could soon be a reality—as early as 2017.
Canavero summed up his proposed head-transplant technique in a medial journal published this month. First, New Scientist reports, both the recipient head and the donor body would need to be cooled. Then the major blood vessels around the neck would be dissected, and the spinal cords of both subjects cleanly cut. Next:
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.
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.
If this theoretical procedure went as planned, he claims, the newly re-bodied patient would be able to walk within a year with the help of physiotherapy.
Canavero says that he already has volunteers, that this could be a miracle treatment for patients whose organs have shut down or nerves degenerated, and that at a medical conference in June, he’ll ask others to join his efforts. But even beyond ethical concerns, the scientific community remain highly skeptical of both his timeline and the viability of his suggested procedure.
"I don't believe it will ever work, there are too many problems with the procedure. Trying to keep someone healthy in a coma for four weeks – it's not going to happen," said Harry Goldsmith, a clinical professor of neurological surgery at the University of California, Davis. Another doctor raised the concern that there is no evidence proving that connecting the brain and spinal cord "would lead to useful sentient or motor function following head transplantation."
And head-transplant attempts don’t exactly have a strong track record in the lab. As New Scientist writes, a Soviet surgeon experimented with transplanting puppy heads on the bodies of larger dogs in 1954 (talk about a horror movie)—but his subjects didn’t live longer than six days. The first successful head transplant was conducted on monkey in 1970. Without spinal fusion, though, the animal couldn’t move or breath on its own.
But Canavero isn’t alone in his optimism. A researcher in China recently performed a head transplant on a mouse. New Scientist writes that this researcher will attempt Canavero’s procedure on mice and monkeys over the next few months.
"If society doesn't want it, I won't do it,” Canavero said. “But if people don't want it in the US or Europe, that doesn't mean it won't be done somewhere else.”