Head transplant
A head transplant is an experimental surgical operation involving the grafting of one organism's head onto the body of another. In many experiments, the recipient's head has not been removed, but in others it has been. Experimentation in animals began in the early 1900s. As of 2024[update], no lasting successes have been achieved.[1][2]
Medical challenges
There are three main technical challenges. As with any
Of these challenges, dealing with blood supply and transplant rejection have been addressed in the field of transplant medicine generally, making transplantation of several types of organs fairly routine;[1] however as of 2017[update] in a field as common as liver transplantation around a quarter of organs are rejected within the first year and overall mortality is still much higher than the general population.[3] The challenge of grafting the nervous system remained in early stages of research as of 2017[update].[1][2]
History
Alexis Carrel was a French surgeon who had developed improved surgical methods to connect blood vessels in the context of organ transplantation. In 1908 he collaborated with the American Charles Claude Guthrie to attempt to graft the head of one dog on an intact second dog; the grafted head showed some reflexes early on but deteriorated quickly and the animal was killed after a few hours.[1][4] Carrel's work on organ transplantation later earned a Nobel Prize; Guthrie was probably excluded because of this controversial work on head transplantation.[2]
In 1954,
In the 1950s and '60s, immunosuppressive drugs and organ transplantation techniques were developed that eventually made transplantation of kidneys, livers, and other organs standard medical procedures.[1]
In 1965, Robert J. White did a series of experiments in which he attempted to graft only the vascular system of isolated dog brains onto existing dogs, to learn how to manage this challenge. He monitored brain activity with EEG and also monitored metabolism, and showed that he could maintain high levels of brain activity and metabolism by avoiding any break in the blood supply. The animals survived between 6 hours and 2 days. In 1970, he did four experiments in which he cut the head off of a monkey and connected the blood vessels of another monkey head to it; he did not attempt to connect the nervous systems. White used deep hypothermia to protect the brains during the times when they were cut off from blood during procedure. The recipient bodies had to be kept alive with mechanical ventilation and drugs to stimulate the heart. The grafted heads were able to function - the eyes tracked moving objects and it could chew and swallow. There were problems with the grafting of blood vessels that led to blood clots forming, and White used high doses of immunosuppressive drugs that had severe side effects; the animals died between 6 hours and 3 days after the heads were engrafted.[1] These experiments were reported and criticized in the media and were considered barbaric by animal rights activists.[2] There were few animal experiments on head transplantation for many years after this.[2]
In 2012,
In 2013, Sergio Canavero published a protocol that he said would make human head transplantation possible.[5][6] In 2016, he announced his plans to do the procedure on Valeriy Spiridonov, a disabled Russian Software Engineer suffering from spinal muscular atrophy, who volunteered for the surgery. Canavero claimed that there is a 90% chance of success.[7] However, Spiridonov later cancelled his participation after falling in love with a woman.[8]
In 2015, Ren published work in which he cut off the heads of mice but left the brain stem in place, and then connected the vasculature of the donor head to the recipient body; this work was an effort to address whether it was possible to keep the body of the recipient animal alive without life support. All prior experimental work that involved removing the recipient body's head had cut the head off lower down, just below the second bone in the spinal column. Ren also used moderate hypothermia to protect the brains during the procedure.[1]
In 2016, Ren and Canavero published a review of attempted as well as possible neuroprotection strategies that they said should be researched for potential use in a head transplantation procedure; they discussed various protocols for connecting the vasculature, the use of various levels of hypothermia, the use of
Ethics and popular opinion
Robert J. White became a target for protestors because of his head transplantation experiments. One interrupted a banquet in his honor by offering him a bloody replica of a human head. Others called his house asking for "Dr. Butcher". When White testified in a civil hearing about
In general, the field of transplantation medicine has been met with resistance and alarm from some quarters as advances have been made;
With regard to head transplantation, there had been little formal ethical discussion published in the literature and little dialogue among stakeholders as of 2017[update]; the plans of Canavero were running well ahead of society's and the medical establishment's readiness or acceptance.
The most appropriate initial form of the procedure was unclear as of 2017[update]. Because grafting the head onto the spinal cord was not possible at that time, the only feasible procedure would be one where the head was only connected to the blood supply of the donor body, leaving the person completely paralyzed, with the accompanying limited quality of life and high societal cost to maintain.[2]
The psychological results of the procedure were unclear as well. While concerns were raised about whether recipients of a face transplant and their social circle would have difficulty adjusting, studies as of 2017[update] had found that disruptions had been minimal. But no transplant had ever been performed where the entire body of an individual is unfamiliar at the conclusion of the procedure, and one of the few documents discussing the ethics in the biomedical literature, a letter to the editor of a journal published in 2015, foresaw a high risk of insanity as a result of the procedure.[2][13]
Popular opinion about Canavero's plans for head transplantation had been generally negative as of 2017[update].[14] Many of these criticisms focus on the state of technology and the timeframe in which Canavero says he will be able to successfully conduct the procedure.[15][16]
Popular culture
Literature
- Professor Dowell's Head (1925), science-fiction novel by Alexander Belyaev, a mad scientist performs head transplants on bodies stolen from the morgue, and reanimates the bodies.
- Arthur Naganor "Gorilla-Man", Marvel Comics scientist character whose head was transplanted onto a gorilla's body.
- JoJo's Bizarre Adventure (1987), Dio Brando, the main antagonist of Phantom Blood and Stardust Crusaders, transplanted his head on Jonathan Joestar's body, the main protagonist of Phantom Blood.
- NOGGIN (2014) by John Corey Whaley; Travis Coates wakes up after undergoing a head transplant after five years of being cryogenically frozen.[17]
Film and television
- The Brain That Wouldn't Die (1962), science-fiction/horror film
- The Incredible Two-Headed Transplant(1971), science fiction/horror film
- The Thing with Two Heads (1972), science fiction film
- Professor Dowell's Testament (1984), Soviet film based on the A. Belyaev story mentioned above
- "Donor" (1999), an episode of The Outer Limits
- The X-Files: I Want to Believe (2008), science fiction film
Video games
- Wolfenstein series, has his head transplanted on to a genetically engineered body in Wolfenstein II: The New Colossus(2017).
See also
References
- ^ PMID 27738901.
- ^ PMID 28110028.
- PMID 27812112.
- ISBN 978-0393324822.
- ^ "Sergio Canavero: Will His Head Transplants Roll? - Neuroskeptic". Neuroskeptic. May 13, 2017.
- PMID 24244881.
- ^ "The surgeon who wants to perform a head transplant by 2017". BBC News. September 20, 2016. Retrieved July 28, 2023.
- ^ Stewart, Will (December 18, 2018). "Man set for world's first head transplant cancels surgery after falling in love". mirror. Retrieved July 28, 2023.
- PMID 27143608.
- ^ Albert Caplan (December 13, 2017). "Promise of world's first head transplant is truly fake news". Chicago Trubune.
- ^ Grant Segall, Dr. Robert J. White, famous neurosurgeron (sic) and ethicist, dies at 84, The Plain Dealer, (September 16, 2010).
- ^ Carla Bennett, Cruel and Unneeded, The New York Times, People for the Ethical Treatment of Animals, (August 21, 1995).
- PMID 26110084.
- ^ Helen Thomson. "First human head transplant could happen in two years". New Scientist.
- ^ Fecht, Sarah (February 27, 2015). "BNo, human head transplants will not be possible by 2017". Popular Science. Retrieved March 6, 2015.
- ^ "Man volunteers for world first head transplant operation". Archived from the original on April 10, 2015. Retrieved April 10, 2015.
- ^ "NOGGIN".
External links
- Bennun, David (2000). "Dr Robert White". The Sunday Telegraph Magazine. Archived from the original on May 23, 2013.