
THEREāS a story doing the rounds about Sergio Canavero. One day, as a 9-year-old, he sought refuge from playground bullies in the pages of a superhero comic. āI myself have surgically rejoined severed neurolinkages,ā declares Dr Strange, in the November 1976 issue of Marvel Team-Up. The brilliant but egotistical fictional surgeon continues: āThe nerve endings have been fused ā the healing process begun.ā The young Canavero was captivated. Four decades on, he announced plans for the worldās first human head transplantā¦
If this story sounds a little too neat to be true, thatās because it probably is. The Italian neurosurgeon, who describes himself as a ābig comics nutā, says he didnāt read that issue until adulthood. He claims the publication that reported the comic as inspiration for his work was mistaken.
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Whatever the true picture, Canavero does not flinch at comparisons with fictional characters. Quite the opposite, he encourages them. He sees a lot of himself in Peter Parker ā aka Spider-Man ā who, as a nerdy student, was bullied by classmates and shunned by girls. After dismissing the Marvel Team-Up story, he sends me PDFs of the relevant comic frames, along with a screen grab of a doctor discussing fusing severed spinal cords from the 2016 film Dr Strange. Canavero says he was the inspiration for that scene. āI have good ties with Hollywood and I can tell you for a fact that line came out of my book.ā
Since 2013 Canavero has been promoting the idea that head transplants ā better understood as body transplants ā are feasible, and should be offered to people with conditions involving muscular and nerve degeneration, for example. The response, in the West in particular, has ranged from disbelief and opposition to the questioning of his motives and scientific credibility.
āReady to rollā
Unperturbed, two years ago Canavero agreed to help set up a team to carry out the procedure in China, working with Xiao-Ping Ren, an orthopaedic surgeon at Harbin Medical University who helped with one of the first hand transplants, in 1999. At the time of writing, Canavero claims several papers supporting the feasibility of human head transplantation will soon be published, that an operation could go ahead by the end of this year and that a āgame-changingā announcement is imminent in China.
āThe team in China is ready to roll,ā says Canavero, who worked as a neurosurgeon at Turin University Hospital in Italy until 2015. āAll the preclinical and clinical studies have been conducted successfully.ā Much of this work will not be published, he says, but insists that what will be published āwill be more than enough to show where China standsā. The precise date of a transplant attempt depends on finding a donor of the right height, build and complexion, he says. āThe problem now is only organisational.ā
Canavero calls his proposed procedure the head anastomosis venture, or HEAVEN. He says it would begin by cooling the donor body and recipientās head to delay tissue death. The heads would be detached and the donor body attached to the recipientās head. Polyethylene glycol (PEG) would help fuse the cords by encouraging the fat in adjoining cells to mesh together. Stimulation from implanted electrodes would help to strengthen nerve connections. Thatās the plan, anyway.
Canavero doesnāt agree with mainstream medical thinking that movement below the neck depends primarily on bundles of long-range nerve fibres in the spinal cord. Inspired by research dating back to the first half of the 20th century, he believes a person undergoing a head transplant could regain close to full movement after those nerves have been severed, thanks to the regeneration and fusing of short-range nerve fibres that are part of an additional, interconnected network of cells in the spinal cord called propriospinal neurons. Think of a fire brigade passing buckets of water along a line if their main hose has been severed.
C-Yoon Kim of Konkuk University in Seoul, South Korea, is part of Canaveroās group and has led animal experiments that use PEG to encourage regrowth of severed spinal cords. In a , Kim claimed that five of eight mice whose spinal cords were severed and treated with PEG regained some movement after four weeks, while none of the mice in the control group did. This year, Renās team reported a similar experiment, claiming that five of nine PEG-treated mice āā. And in a widely criticised experiment in 2016, Kimās team at the neck regained 90 per cent of its motor function within three weeks, with the aid of PEG. Critics pointed out there was no control in the study and no data proving the degree of damage to the dogās spinal cord.
Ren and Canavero also published a paper in the journal Surgery, in which they claimed to have carried out a monkey head transplant, described as successful on the basis of āā. āThereās not such a big difference between animals and humans ā the basic functions, physiology and the possibility of recovery are the same,ā says Kim. āI believe we will succeed in the human operation in the near future.ā
Many scientists refuse to comment on the record about Canaveroās work, often because they have serious doubts about the published papers. Most who have commented say a successful human head transplant is far from feasible. āThere is no way that I know of, that has been published, that would allow fusion of the spinal cord,ā says JosĆ© Oberholzer, director of the Charles O. Stickler Transplant Center at the University of Virginia, Charlottesville. āThe rest, including reconnecting the blood vessels and the airways, is theoretically possible but very challenging, and carries major risks of complications from leaks and immune system rejection.ā
Others have used words such as ācharlatanā and āself-promoterā. Canavero dismisses his critics as too short-sighted to share his vision. āThe history of science is full of people being called nuts and then going on to prove their point,ā he says. āThe academe tried to destroy me, they tried everything to stop me, to slander me, but they failed. Itās no problem: I practice ju-jitsu and the mindset is let your enemy come to you, and then exploit his momentum to bring him to the ground.ā
Canavero claims the media has failed to report his work properly. And in his efforts to seek favourable coverage he tries tactics more often employed by spin doctors. For example, he offers me early āexclusiveā early access to as-yet unpublished papers if I interview specified people, avoid others who have criticised his work, show him my article in advance and we agree āmutually acceptableā terms. I politely refuse his offer.

Canavero, now 52, does not want to talk about his early years, but the few details he does give me could help explain why he self-identifies as an outsider. He describes growing up as an only child in a poor neighbourhood of Turin in a ādifficult family situationā. He says he was bullied by classmates because he was bright, which made him resentful. āIām a loner, Iām a maverick,ā he says. āI believe the initial suffering when I was a child had a lot to do with it.ā
When I ask Canavero about what motivates him, he does not mention helping patients. āThe goal is to understand the nature of consciousness and to answer the basic question of what happens when we die. I believe consciousness is not generated in the brain, which merely acts as a filter.ā
āI believe consciousness is not generated in the brain, which is merely a filterā
Canavero believes the mind and body are separate and that so-called near-death experiences support this view. He wants to show that those who dismiss these reports as hallucinations are wrong.
āMy idea is to generate near-death experiences,ā he says. āWhen you detach a head or a brain, the brain is cooled so there is no electrical activity and no blood flow, that brain is clinically dead. Patients will tell us about their near-death experiences and we will know for a fact that they could not have been generated by the dying brain.ā That will change how we consider ourselves as human creatures, he says. āThat will trigger the greatest revolution ever. That is the final goal, the real goal.ā
āOf course, there is another goal,ā he continues, āwhich is life extensionā. The book Canavero says inspired Hollywoodās scriptwriters is his 2014 work Head Transplantation and the Quest for Immortality, in which he predicted the transfer of human brains to artificial bodies āpossibly by 2025ā. He also claims to be assembling a team to perform a human brain transplant, and that this procedure will happen within three years.
Many believe the chances are remote that Canaveroās aspirations will become reality any time soon. āThe complexity of what he is proposing is enormous,ā says neurophysiologist Peter Ellaway, an emeritus professor at Imperial College London. āI think his aims are almost in the realm of science fiction. In my opinion this will never happen.ā
Others fear indirect downsides to Canaveroās actions, even if no head transplant is ever attempted. āBeing a transplant donor is one of the very few purely altruistic things a human can do,ā says Oberholzer. āWhen someone wants to be the hero by putting on this audacious show, people may be put off donating their organs or bodies if they think doctors are going to do something crazy like this.ā
Superheroes arenāt the only fictional characters Canavero likens himself to. Victor Frankenstein is another. When I confess I havenāt read Mary Shelleyās Frankenstein, he emails me quotes from the novel. Such as: āWhence, I often asked myself, did the principle of life proceed? [ā¦] I was surprised, that among so many men of genius who had directed their inquiries towards the same science, that I alone should be reserved to discover so astonishing a secret.ā
Dr Strange-meets-Victor Frankenstein, with a dash of Spider-Man, might make for an entertaining science fiction character. And Canavero certainly loves to entertain, playing on his renegade scientist image. āAre you sitting tight?ā he asks, in full showman mode, at the start of a recording of his . āIām about to give you one hell of a ride.ā He smiles at his audienceās nervous laughter. But fast-forward to today, with the scene shifting from the stage to the operating theatre, and the Canavero carnival risks turning into a horror show. With real-life patients at stake, no oneās laughing any more.
A century of head swapping
1908
First dog head transplant
French surgeon Alexis Carrel and American physiologist Charles Guthrie graft one dogās head to anotherās neck, connecting the arteries. The head spends 20 minutes without blood flow, but then shows some reflex responses. It is euthanised after a few hours.
1954
Dog torso, maintained blood supply
Soviet surgeon Vladmir Demikhov grafts the heads and torsos of small dogs, including heart and lungs, on to the backs of larger dogs. The transplanted dogs can see, move and lap water. One survives 29 days.
1965
Brain-only graft, dogs
American neurosurgeon Robert White grafts six isolated dog brains onto the circulatory systems of six other dogs. Metabolism and EEG monitoring indicate the brains may have been in a functional state.
1970
Monkey ā blood vessels connectedWhite connects monkey heads to decapitated monkey bodies via only the major blood vessels. The heads were able to chew, swallow, and track with their eyes ā for up to 36 hours.
2015 ā 2017
Rodent head transplants
Chinese surgeon Xiao-Ping Ren and team, including Sergio Canavero, publish research with and . They graft small rodent heads onto the necks of larger ones. Of 40 transplant/donor mouse pairs, 12 reportedly survive more than 24 hours.
2016
Monkey head transplant
Ren, Canavero and colleagues make claims of a head transplant, issuing a photo of a monkey with stitches in its neck. In the , they dub the operation a success, based on āunpublished observationsā.
This article appeared in print under the headline āDr Strange meets Dr Frankensteinā