When Italian neurosurgeon Sergio Canavero recently announced his plans to conduct a human head transplant, that is, to put an entire head on a new body, virtually all other neurosurgeons, physicians and bioethicists called the proposal utterly absurd.
They called Canavero "nuts" and labeled his proposed operation something "worse than death." That's not a good sign for someone who says he needs 150 doctors and nurses to help him perform the 36-hour-long surgery.
Now Canavero is giving everyone a scare again.
He seems to have found his first volunteer patient: Valery Spiridonov, a 30-year-old Russian man, who has a rare genetic disorder called Werdnig-Hoffmann disease, in which motor neurons in the spinal cord and the brainstem gradually die, resulting in shrinking muscles and paralysis.
And Canavero wants to fix this by giving the patient a whole new body. Here's how the operation is said to be performed:
"It 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… 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… Next, the muscles and blood supply would be sutured and the recipient kept in a coma for three or four weeks to prevent movement…When the recipient wakes up, Canavero predicts they would be able to move and feel their face and would speak with the same voice."
Experts have pointed out multiple problems in every step of the proposed surgery. For example, gluing two ends of severed spinal cords will not make nerve fibers fuse well into each other, as nerve cells immediately form scar tissue. Even if the glue worked, connecting millions of nerves together is not possible. Other big-picture issues include getting the immune system to accept the new head, and keeping the head alive. Scientists are still figuring out how low they can bring the temperature before brain tissue starts to act up.
Monkey head transplant sketch from Robert White et al. 1971
While we are terrified of the idea, Canavero sounds pretty chill for a man who plans to do an unprecedented operation, even if it were realistic. In an interview with Tanya Lewis of Live Science, Canavero said, "Once I attach a new body, I fully expect the head and body to adapt to each other." And he is in a rush, as he sees head transplants as the new Moon shot: "If America doesn't [attempt the procedure], China will," he said.
Spiridonov has pointed out that his debilitating disease doesn't really leave him many other choices anyway, and that for any groundbreaking achievement, there will have to be some people who try it first. "In the end it is like with astronauts," he told Mail Online.
But there's a difference between innovation and bad science. Although Canavero is making headlines, gets cover stories and gives lectures on TEDx like a star, he says the sort of things that madden most scientists. Biologist Paul Zachary Myers details some of the scientific problems with Canavero's claims in this blog post, but the most glaring of all perhaps is that Canavero doesn't present any evidence that the surgery works. He says we now have the technical abilities to perform such a sophisticated surgery, but hasn't done any preliminary experiments to back up this claim.
The last time anyone attempted to do anything like this was in 1970, when U.S. scientists transplanted the head of one monkey on to the body of another. The resulting patched-up monkey was paralyzed and breathed with assistance. It died nine days later.
"This procedure will not work. If it was a good procedure, show me a dog that has undergone it, walking across the stage with a transplanted body," Myers writes. "Try it with monkeys first. But he can't: the result would be, at best, a shambling horror, an animal driven mad with pain and terror, crippled and whimpering, and a poor advertisement for his experiment. And most likely what he'd have is a collection of corpses that suffered briefly before expiring."
The good news is that, no one thinks a surgery like this will actually get ethical approval, not to mention backing from 150 medical professionals who would want to join Canavero in this Frankensteinian adventure.