Controversial Italian
neurosurgeon Sergio Canavero claims he could perform the world’s first ever
human head transplant in 2017, despite ethical and scientific reservations from
many of his colleagues.
“The Wright brothers flew their first plane when
every so-called expert in the world thought that this was impossible. So, I
don’t believe the word ‘impossible’ – I have been working on this project for
30 years, and the technology is now there,” Canavero, who heads the Turin Advanced
Neuromodulation Group, told Sky News.
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Canavero’s team, which
previously touted their plans for a whole-eye transplant, published a paper
outlining the procedure two years ago, and say they are now ready to find
subjects for the experimental procedure.
"If society doesn't want it, I won't do it.
But if people don't want it in the US or Europe, that doesn't mean it won't be
done somewhere else,” the neurosurgeon told
the New Scientist.
Prior to the surgery, the
two bodies would be cooled, to preserve them better without oxygen, and then
their necks would be sliced open and major blood vessels connected between the
donor’s body and the recipient’s head.
The key stage would be
the severing and re-attachment of the spinal cord, which would have to be
cleanly sliced, and would then present two “spaghetti-like”
bundles of nerves, which would need to be connected to each other. Canavero
foresees this being done with polyethylene glycol, a material that enables fat
in different tissues to mesh.
The neck would then be
stitched shut, and the patient placed in an artificial coma for four weeks,
allowing the body to heal without movement.
Canavero previously
estimated that the pioneering surgery would cost upwards of €10 million, and
that the perfect initial recipient would be a person with a young, healthy
brain, suffering from muscular dystrophies or metabolic disorders. He proposes
initial experiments where both of the individuals in the surgery would be
brain-dead.
‘No evidence’ it would work
Most
of the scientific objections to the procedure focus on the impossibility of
restoring body control after the refusing of the spine. Currently, it is
commonly impossible to overcome paralysis when a spinal cord is completely
severed, even when the rest of the body belongs to the same person. An
ambitious procedure performed by Polish doctors last year, managed to restore
movement by implanting lab-grown nerve cells into the spine.
But
Richard Borgens, director of the Center for Paralysis Research at Purdue
University, Indiana, said that Canavero’s surgery offers no such guarantees.
"There is no evidence that
the connectivity of cord and brain would lead to useful sentient or motor
function following head transplantation,” he told the New
Scientist.
"This is such an
overwhelming project, the possibility of it happening is very unlikely. 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, himself a leading
expert on reconnecting spinal tissue that enables paralyzed people to walk
again.
Yet
Canavero can reassure himself that his ‘Frankensurgery’ is not without
precedent. The first attempted dog head transplant dates back to more than a
century ago, and Soviet scientist Vladimir Demikhov performed multiple such
procedures in the 1950s. US surgeon Robert J. White famously performed a head
transplant between two monkeys in 1970, with the survivor living for nine days.
In
all of the previous procedures, the recipients remained paralyzed, and all
struggled with immune rejection of the new body parts, though with improved
techniques, this is not an insurmountable problem.
Ethical
problems – from religious considerations, to the simple ickiness-factor – are
also likely to slow down progress.
"I believe that what is
specifically human is held within the higher cortex. If you modify that, then
you are not the same human and you should question whether it is ethical. In
this case, you're not altering the cortex,"
said Patricia Scripko, a neurologist and bioethicist at the Salinas Valley
Memorial Healthcare System in California, who does not believe the procedure is
possible, but insists it is not objectionable.
"If a head transplant were
ever to take place, it would be very rare. It's not going to happen because
someone says 'I'm getting older, I'm arthritic, maybe I should get a body that
works better and looks better'."
Despite
the myriad objections – and even his supporters are skeptical of the two-year
timeframe – Canavero will now have the chance to convince his colleagues, when
he will present his specific plans for the surgery to the prestigious congress
of the American Academy of Neurological and Orthopedic Surgeons in Maryland in
June.
"I first spoke about the idea two years ago, to get people talking about it. I'm trying to go about this the right way, but before going to the moon, you want to make sure people will follow you," he said.
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