Sergio Canavero: Will His Head Transplants Roll?

By Neuroskeptic | May 13, 2017 2:07 pm

Will the first human head transplant happen soon? According to Sergio Canavero, it will – and he’ll be the man to do it.


In 2015, Canavero announced his intention to carry out the pioneering operation, with the head being that of a Russian man, Valery Spiridonov, who has a muscle degenerative disease. The source of the donor body was never specified. More recently, Canavero has said that a Chinese patient will be the first to have their head transplanted.

So who is Sergio Canavero, and what’s his background? The Turin-based Italian neurosurgeon has had a productive research career: his name appears on 112 papers on PubMed, dating back to 1990. His main interest is pain, specifically central pain syndromes, in which damage to the brain or spinal cord leads to chronic, often difficult-to-treat pain.

Canavero’s first paper on head transplantation was published in 2013 (in a journal that regular readers may be familiar with.) However, his interest in radical transplant surgery dates back 25 years: in 1992, Canavero published a speculative paper on “Total eye transplantation for the blind: a challenge for the future.” What if, Canavero asked, it were possible to implant an donor eye into a recipient’s socket, before connecting it up to the brain by encouraging the optic nerve to grow into place? He never revisited this idea.

The 2013 paper introduced two acronyms which Canavero has gone on to use regularly. HEAVEN, or “HEad Anastomosis VENture”, refers to the overall project to carry out the first human head transplant. GEMINI, the etymology of which is unclear, is the key procedure that will make the head transplant possible: the fusion, or connection, of two severed spinal cords into one.

Spinal cord fusion or reconnection is, to put it mildly, a technical challenge. It’s the holy grail of spinal cord injury – the power to reconnect a severed spinal cord could allow countless people to move, and feel, again. But it isn’t easy.

Canavero claims to have cracked the problem. In September 2016, Canavero announced that “GEMINI has landed – spinal cord fusion achieved.” The secret, he says, is a combination of a very sharp cut – to minimize damage to the nerve cells  – and PEG, polyethylene glycol. PEG, Canavero says, has “the uncanny capacity to literally re-fuse neuronal cell membranes submitted to mechanical disruption.”

In the same issue of the journal, Canavero’s South Korean collaborator C-Yoon Kim reported that PEG produced “partial restoration of motor function” in mice whose spinal cords were severed. The Kim et al. paper is to date the only evidence that Canavero’s GEMINI works, and the results are not very impressive. Compared to a control group, the PEG-treated mice recovered slightly better from the lesion, but the difference wasn’t statistically significant. All of the control group and 3/8 of the PEG group died within 2 weeks


As well as mice, Kim et al. also studied the effects of PEG in re-fusing the spinal cords of rats, but the results of this experiment were inconclusive because most of the animals died due to “a storm that filled the underground lab.”

Beyond fusing the spinal cord, a head transplant would also require connecting up blood vessels, such that the head could receive blood from its new body. This is a technical challenge, although not perhaps as tricky as spinal cord fusion. As early as 1908, Charles Guthrie connected the head of a dog onto the body of another dog, and there have been several refinements of this eerie procedure since.

Canavero and a team of Chinese researchers recently reported the creation of a Cronenbergesque two-headed rat, although there was no attempt at spinal cord fusion here – just blood vessel redirection which allowed the second head to live attached to the other rat’s body (for 6 hours).


What about the ethics of all this? Are these animal experiments justified? And if Canavero ever gets his hands on a human patient, what then? Even on an optimistic view, someone undergoing this surgery runs a high risk of death, paralysis, or pain – the very central pain syndrome that Canavero spent his previous career studying and treating.

Even with the patient’s informed consent, it’s not clear that decapitation is compatible with the Hippocratic Oath. Perhaps Canavero will be able to find a hospital ethics committee somewhere willing to approve the study, but would that make it ethical? Here’s the words of a 2001 paper in the Lancet on the topic of ethics:

When decisions are left largely to the principles of individual doctors or local ethics standards, unethical actions may ensue… public statements by physicians that they acted without abuse, according to the local standard of care, and after approval by local ethics committees has not made [research that violates generally accepted standards, such as the Declaration of Helsinki] more ethical.

Canavero would do well to remember these words; after all, he wrote them.

Overall, my impression is that Canavero is nowhere near ready to carry out a head transplant and I doubt that he will ever attempt the procedure. He seems sincere in his motivations, and the animal experiments, while inconclusive, are not completely worthless. But the fact is that Canavero and his collaborators have yet to show that their techniques can reconnect the two halves of the spinal cord of the same animal with a good functional outcome in the long term – let alone of two animals.

As P. Z. Myers said, “show me a dog walking across the stage with a transplanted body”, and only then it might make sense to start thinking about a human trial.

Is it fair to compare Canavero to the disgraced ‘pioneer’ of stem-cell therapy, Paolo Macchiarini? There are certainly similarities between the two surgeons – such as their flair for publicity, and claims to have found the ‘holy grail’ of their fields of medicine. I hope however that Canavero won’t end up like Macchiarini has: his reputation in ruins, his science discredited, and his patients dead.

  • OWilson

    “A brain is a terrible thing to waste”, literally! :)

  • Leonid Schneider

    I personally am puzzled why anyone takes Canavero seriously. Unlike Macchiarini and his organ making, Canavero’s “science” of head transplant lacks peer support which at least lets it seem scientific. Still, the mere fact that Canavero published something in this regard in some “peer reviewed” journal makes many stop and think: what if he is onto something?

    • Tim Yorty

      what drugs and how many of them would be used to prevent “cranial rejection”?

      • King of monsters

        it would never get that far once the spinal cord i cut your dead and even his own results show that the few cases where mice survived the surgery, they never fully recovered and died within two weeks meaning at best he causes you to suffer horribly for a week or more before you die.

    • smut clyde

      He’s a Consulting Editor on the SNI Editorial Board, and they are happy with him regularly editing Special Issues for himself and his collaborators. I guess Canavero’s image as Free-Thinking Maverick fits the policy of SNI. And they don’t seem to care that he’s an incompetent maverick, with a model of spinal-cord function that’s 180° out-of-step with what everyone else understands.

      Most of the criticisms of Canavero seem to target the ethical issues. That is enough to convince the SNI readership that he must be correct, and bring them rallying to defend him. “Who are these bleeding-heart liberals, and their ‘ethics’, thinking they can stand in the pursuit of Knowledge?!”

      Anyway, because SNI and one or two other spinal-carpentry journals give Canavero a microphone, it would take a brave journalist to stand up and announce “This guy’s claims are complete garbage, let’s not bother reporting them.”

      There has been some criticism of his South Korean colleagues and their habit of reporting results at press conferences rather than technical reports. With videos of animals that are no longer alive to be examined, and sketches of the spinal damage rather than X-rays. I get the impression (e.g. from a report in New Scientist) that the journalists are *thinking* “Complete charlatan”, but they are not brave enough to say it out loud.

  • smut clyde

    September 2016, Canavero announced that “GEMINI has landed – spinal cord fusion achieved.”

    That paper — letter? Advertisement? — begins in gloriously grandiose terms and just gets better:

    In June 2013, the world was taken by storm by the announcement that a full head (or body) transplant was possible.[1] This key achievement would have been made possible by the GEMINI spinal cord fusion protocol.

    If I am correctly reading the convoluted tense there (“would have been made possible”), Canavero made this world-storming announcement without knowing what his GEMINI protocol would be. Perhaps this is why he has not yet reverse-engineered a longer form of the acronym.

    After that, he enters full-Rotwang fist-shaking “The fools! I’ll show them all!!” territory. The rest of the letter / advertisement is all “hysterical reaction” … “dispel that hysteria once and for all” … “previous misbegotten dogma” … “the defining event of the 21st century”.

    • Sofia Washington

      I’am freelancing on the internet, completing normal tasks that only requires from you personal computer or laptop computer and just internet accessibility and I couldn’t be thrilled… Six months have crossed since i started this and i received up till now altogether 36 thousand dollars… Basically i profit almost $80/hourly and work for 3 to four h on a regular basis.And spectacular point regarding this work is that you can actually decide when to work by yourself as well as for how long and you get money by the end of each week.>>>> S.COOP/25ury

    • Tim Yorty

      and in the end…”Rotwang falls to his death.”

  • smut clyde

    most of the animals died due to “a storm that filled the underground lab.”

    Expected laboratory to be concealed beneath an island volcano. Am disappointed.

  • jhewitt123

    Shouldn’t we really be talking about transplanting human heads on to tigers? Or blue whales? Inside a blue whale cranium, your brain could rapidly expand to fill the whole volume.

  • CL

    posing with a phrenology map is kind of ironic

  • janvones

    Canavero should be defrocked and institutionalized, as he’s an obvious danger to himself and others.

    Oh, and I have a quart of polyethylene glycol in my closet. It’s a superb…


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  • Doug Nusbaum

    This story would make more sense, and be more logically consistent if one replaced Ethical and similar words with “what I / my group likes”, and unethical with ” what I / my group really does not like”. If you think that this is BS, then I invite you to look up the word ethical and chase down all the fuzzy words used to define it. At the bottom / core you will find like and approve.

    • Doomroar

      But then what is the difference between ethics and morals according to this? they both will be boiling down to be the same thing.

  • smut clyde

    Canavero’s South Korean collaborator C-Yoon Kim reported that PEG produced “partial restoration of motor function” in mice whose spinal cords were severed

    I got around to reading that paper, and Holy Guano Batman!, it is even crazier than you expect.

    Kim starts out talking about “a resealing (sealant effect of PEG) of the membranes of neurons injured by the nanoblade transection”… where “nanoblade” sounds like some weapon that a high-tech ninja character in a Manga comic might wield. The idea seems to be that a sufficiently sharp blade — sharp at the molecular level — can cut cells into two pieces with sufficiently little trauma to their internal structure that in the presence of PEG, the severed membranes will knit themselves together again. Except in the alleged experiment itself, the rats’ spinal cords were cut with a #11 scalpel, which at the cellular level is about as sharp as a car bumper, crushing cells into oblivion rather than cutting them.

    The PEG is enhanced with “graphene nanoribbons”. Why? “In other words, in order to improve and accelerate the recovery of function, we tested PEG enhanced by these electrical conducting nanoribbons. PEG‑GNRs would achieve both membrane fusion, facilitate initial electrical conduction, and then act as a scaffold for sprouting fibers.” Which is to say, magic.

    Electricity is involved. Canavero writes elsewhere about the need for electric current for cellular rejuvenation. He mentions Frankenstein as a role-model. I am not making this up. If other researchers cannot replicate Kim’s experiment, it is probably because the lightning strikes providing the energy for the laboratory were not sufficiently powerful.

    The idea, apparently, is not to restore function to the myelinated tracts that make up the afferent and efferent pathways of the spinal cord, but to the “cortico‑truncoreticulo‑propriospinal (CTRPS) pathway”. This is a part of the grey-matter core of the spinal cord that is unknown to textbooks and recognised only by Canavero and his colleagues, but evidently it can provide both sensory and motor connections, so you have to wonder why the myelinated parts of the spinal cord are necessary.

    Kim does not have an academic email address. He is “”.

    I can’t imagine that the whole lurid fabrication could have been published anywhere, not even in SNI, except that the editor of that issue was one Sergio Canavero.

    • Neuroskeptic

      Wow. This is even crazier than I thought.

      Perhaps Kim’s basement (the one that got flooded) should be known as the Camelot Lab, because it’s a very silly place.

      • smut clyde

        Here’s the paper that cites Frankenstein’s precedence in the use of electrical stimulation in rejoining bifurcated neurons:

        The details of what Kim is claiming are instructive. He claims that he dissected each rat down to the cervical vertebrae and split open a vertebra to expose the cord so he could hook up the cord and cut it with a #11 scalpel… which at the cellular level is a blunt instrument, he might as well have used an old woodwork chisel… the “nano-blade” invoked in the introduction evidently wasn’t needed after all. Then he swapped the two stumps with his fractal-conductive-graphene-infused PEG and put them back with such micron-level precision that the two halves of each cell were adjoining again, and the cut membranes were contiguous so that they could knit themselves back together (with the help of electricity). After a few days to recuperate, the rat that survived the flooding of the underground laboratory had regained full control of its body.

        I have no idea where Kim fits on the “deranged-to-fraudulent” spectrum, but none of this really happened.

  • Erik Bosma

    I’ve picked up a little head for less than $50 and everything went smoothly. But I’m pretty sure I used ethyl alcohol first. At that price, I believe it was quite a lot of ethyl alcohol.

  • SayWhat?

    Might it not be easier to “read” the I/O data flow of the spinal cord and then digitally bridge the gap at the “cut”? It may not be perfect at first but, I think that’s how the Borg did it.

  • Lizette Ostojic

    i want to know , this will be head transplant /?? our brain is
    ” the unique ” person. Is who we are. transplanting a head, it will be transferring that person to a new body or what??? what really is transferring the inside???

  • Ritika Garg
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  • Kenrod

    I know I am late here, but I am surprised that neither the article or comments takes note that James Tour of Rice is a coauthor on at least one of these papers (the one with the drowned rats in the control group). In fact, the polyethylene glycol/graphene nanoribbon elixir is being called Texas-PEG. He has also recently presented the “results” via an American Chemical Society webinar.

    • smut clyde

      Claiming to restore mobility to “rats” plural, when there’s only one that survived the laboratory flooding? Tour and Sikkema are scammers, then.

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  • muhammad faisal

    i want donate my head for this experiment , i am patients of paraplegia age 36 .

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About Neuroskeptic

Neuroskeptic is a British neuroscientist who takes a skeptical look at his own field, and beyond. His blog offers a look at the latest developments in neuroscience, psychiatry and psychology through a critical lens.


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