Medical science has advanced an astounding amount in the last 50 years or so and we can
do things today that a half a century ago even in that era’s science fiction would
have been considered science fiction.
By the same token though, there were things done in the 1950s and 1960s that people today
are still skeptical actually happened, like all those experiments that resulted in a bunch
of two headed dogs.
Said experiments were conducted by one, Vladimir Demikhov, a Soviet scientist who is noted
as being a pioneer in the field of organ transplantation.
Dr. Demikhov was responsible for, amongst other things, pioneering the use of immuno-suppressants
in organ transplants and designing the “first mechanical cardiac-assist device”, essentially
the precursor to modern artificial hearts.
With this latter device, Demikhov was able to take over the cardiac function of a dog
for around five hours, an experiment notable for being “the first ever in which circulation
was maintained in an animal whose heart had been excised”.
Prior to Demikhov, this was a feat that many believed to be impossible.
Demikhov is also known to have performed the first heart transplant in 1946, in this instance
on a dog; this was a full 21 years before the first human transplant took place and
was a major step towards the latter ever happening.
It has been noted that Demikhov was a genius whose “successes heralded the era of modern
heart and lung transplantation”.
Despite this glowing praise in some circles, his contributions have largely been overlooked
outside of the medical community due to the infamy of his later, more audacious experiments.
This brings us back to the two headed dogs.
Sometime in the early 1950s, spurred on by the success of his experiments involving the
transplantation of organs in dogs, including several experiments in which he’d managed
to successfully transplant multiple organs of the same type into the same animal, Demikhov
began toying with the idea of transplanting the most valuable organ of all- the brain.
Demikhov is said have been inspired by the work of his peer, Dr Sergei Brukhonenko, another
Soviet medical pioneer known for inventing a machine capable of artificially simulating
the functionality of the heart and lungs, albeit on a temporary basis.
Like Demikhov, the work of Brukhonenko is largely overlooked due to an experiment involving
dogs.
In Brukhonenko’s case, he infamously kept the decapitated heads of several dogs alive
using the aforementioned machine for a number of hours, proving that it was possible to
keep the brain alive and functional after almost unthinkable trauma.
Footage of these experiments appears in a documentary released in 1940 aptly titled
“Experiments in the Revival of Organisms”.
However, the veracity of this footage, which shows a decapitated dog’s head connected
to a heart lung machine blinking and responding to various stimuli, has been the topic of
heated debate for many years and even to this day, there’s no agreement on whether it
actually shows what it claims.
To be clear, Brukhonenko’s experiments on reanimation are well documented and there’s
little doubt they actually took place as he claimed.
However, there is some uncertainty about whether the particular documentary actually shows
real experiments or whether it was a reenactment of sorts after the fact for propaganda purposes.
Getting back to Demikhov, his idea was as simple as it was shocking.
He would prove that the brain, like any other organ, could be successfully transplanted
by cutting the head off a dog, keeping it alive using the same technology as Brukhonenko
had done, and then transplanting it onto the body of another dog.
All in all, it’s recorded that Demikhov performed this experiment “over 24 times”
with varying degrees of success- success in this context meaning that the subjects survived
the ordeal and even displayed some awareness of their surroundings and the ability to respond
to stimuli.
After successful transplants, the dogs typically died days later as a result of immune responses.
Of course, scientists being good scientists, many were skeptical that Demikhov could actually
perform such a procedure successfully- they wanted direct proof.
So to silence the skeptics, Demikhov invited LIFE magazine to document and photograph one
of his experiments in 1959.
The resulting article, titled “Russia Two-Headed Dog” documented the entire transplant procedure
including the preliminary preparations, during which Demikhov introduced the journalist writing
the article to the two dogs he was about to sew together, Shavka, a small 9 year old female,
and Brodyaga, a large stray of which little was known.
two-headed-dog2Demikhov then further “endeared” himself to any potential readers by saying
that Brodyaga was Russian for “Tramp” and that he personally felt the dog was quite
lucky since “two heads are better than one”.
Prior to the actual operation, Demikhov also introduced the interviewing journalist to
a dog called Palma, which he revealed had two hearts thanks to an operation he performed
on the animal a few days earlier.
The article culminated in Shavka’s head and fore legs being successfully grafted onto
Brodyaga’s body.
The operation was such a success, in fact, that Shavka’s decapitated head was even
able to lap a few mouthfuls of water from a bowl with some assistance, something Demikhov
did purely for the cameras present as Shavka’s throat was not attached to Brodyaga’s stomach,
meaning it couldn’t gain any nourishment from food or water via normal means.
In the end, the two dogs survived for four days before dying from complications of the
surgery, which came as a surprise to Demikhov who revealed that some of his previous subjects
had survived for as long as 29 days.
two-headed-dog-1Despite the potential implications of Demikhov’s research, this particular
bit of his life’s work was largely dismissed by the wider scientific community with the
exception of a few scientists, most notably American neuroscientist Dr. Robert White,
who infamously and successfully repeated the experiment using rhesus monkeys in the 1970s.
While the two experiments were basically the same and set out to prove the same point-
that a full head transplant was possible- there were a number of differences.
Beyond the fact that a monkey head transplant is much closer to the procedure needed for
a human head transplant, which is the end goal of this research, Demikhov had attached
the head of one dog to the body of another, still living dog, while White went one step
further and transplanted the head of one monkey onto a headless monkey body.
Doing this meant that, with the exception of the spinal cord, every major artery and
even the windpipe and throat could be connected successfully to the new host body, allowing
for more or less normal body function, other than the typical issues associated with paralysis.
What’s more, the transplanted monkey head retained full awareness of its surroundings
to such an extent that literally the first thing it did upon regaining consciousness
was bite the finger of a medical assistant.
With these results in hand, White concluded that performing the same surgery on a human
would soon be possible and that the person would not only potentially survive, but suffer
few ill effects other than the obvious (then) irreversible damage to their spinal cord,
something that wouldn’t be an issue for terminal quadriplegics, who White felt would
be the best candidates for such a procedure.
However, he also stated,
Whether such dramatic procedures will ever be justified in the human area must wait not
only upon the continued advance of medical science but more appropriately the moral and
social justification of such procedural undertakings.
Others have also taken up the research area despite the ethical controversy, citing the
massive benefit such procedures would provide to countless individuals, such as those with
terminal cancer, severe muscular atrophy, paralysis from the neck down, people with
multiple organ failure, etc.- essentially, anyone who has an otherwise fully functional
brain, but whose life support systems (in sum comprising their body) are failing in
some way, which ultimately would cause the premature death of the brain.
head-transplantAs to the current state of this brand of research, Italian neurosurgeon
Sergio Canavero states that he expects the technology will be ready as soon as 2017 to
perform a successful human head transplant.
He even has a candidate lined up for the procedure, Valery Spiridonov (pictured right), who suffers
from Werdnig–Hoffmann disease and whose health is declining significantly as he ages.
For Spiridonov, there will come a time when his only hope of survival is transplanting
his head to a donated body, at which point even a slim chance of success in such a surgery
is preferable to the alternative.
Not satisfied to leave the head transplanted individual paralyzed, Dr. Canavero even managed
to re-knit the spinal cord of a rat after severing it, allowing the animal to eventually
regain control of its body.
German researchers in 2014 also reported similar success repairing a severed spinal cord in
a rat using a similar technique.
Said Canavero, “This experiment is an important piece of our puzzle because now we know for
sure that it is possible for a spinal cord to grow back together.”
Beyond Dr. Canavero, arguably the world leader in head transplants is one Dr. Ren Xiaoping
of China who has led a team that has made significant advancements in the procedures
in this arena.
Dr. Canavero recently commented on Dr. Xiaoping’s work, “I can tell you that within the last
18 months, about 1,000 similar surgeries were performed in China, and I can say that this
very rat (the one with the repaired spinal cord) is not the best sample.
We will say more as soon as the information is published in the scientific magazines,
because until then it is restricted by copyright.”
As for Dr. Xioaping, he noted of the ethics of the procedure that back when things like
human heart transplants were first becoming a real possibility, there was just as much
controversy surrounding if this area of research, let alone applying it to a human procedure,
was morally acceptable or not, and that “many people say a head transplant is not ethical.
But what is the essence of a person?
A person is the brain, not the body.
The body is just an organ.”
Essentially, the body is just a magnificent life support system.
For some, theirs fails resulting in an otherwise healthy brain that might have lived many more
years dying as well.
Beyond practicing procedures on cadavers, presently Dr. Xioaping and his team have successfully
transplanted numerous heads of rats and other animals onto new host bodies, including transplanting
monkey heads, which, as previously noted, is a relatively similar procedure to transplanting
a human head.
Dr. Xioaping reported that (currently) a monkey head transplant takes approximately 20 hours
to complete and he expects a human head transplant to take an additional 10-20 hours.
However, before Dr. Xioaping is willing to try the procedure on an otherwise terminal
human patient, he stated that advancements still need to be made to ensure an extremely
high probability of success.
Towards this end, he and his team are working on improving methods to cut the spinal cord
cleanly enough to allow for a high probability of reconnecting to the spinal cord in the
new body, advancements in suppressing organ rejection, and ability to better maintain
blood pressure to the brain throughout the procedure to ensure no brain damage.
Despite the technical obstacles remaining and some amount of public opposition to such
human procedures, even if they ultimately are life saving for many with otherwise terminal
conditions, Dr. Xioaping posited in March of 2016,
We are getting closer and closer to our goal of a human head transplant.
I don’t have a timetable.
It is very complex work.
We can’t say it will happen tomorrow – but I am not ruling out next year.