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Head transplant

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A head transplant is a surgical operation which involves the grafting of one organism's head onto the body of another. It should not be confused with another, hypothetical, surgical operation, the brain transplant. Head transplantation involves decapitating the patient. Although it has been successfully performed using dogs, monkeys and rats, no human is known to have undergone the procedure.[1]

Since the technology required to reattach a severed spinal cord has not yet been developed, the subject of a head transplant would become quadriplegic unless proper therapies were developed. This technique has been proposed as possibly useful for people who are already quadriplegics and who are also suffering from widespread organ failures which would otherwise require several distinct and difficult transplant surgeries.

History

Transplantation of a dog-head in the GDR by Vladimir Demikhov in 13. January 1959

As the book Stiff: The Curious Lives of Human Cadavers explains:

On May 21, [1908, Charles] Guthrie succeeded in grafting one dog's head onto the side of another's neck, creating the world's first artificially two-headed dog. The arteries were grafted together such that the blood of the intact dog flowed through the head of the decapitated dog and then back into the intact dog's neck, where it proceeded to the brain and back into circulation. Guthrie's book Blood Vessel Surgery and Its Applications includes a photograph of the historic creature. Were it not for the caption, the photo would seem to be of some rare form of marsupial dog, with a large baby's head protruding from a pouch in its mother's fur. The transplanted head was sewn on at the base of the neck, upside down, so that the two dogs are chin to chin, giving an impression of intimacy, despite what must have been at the very least a strained coexistence....too much time (twenty minutes) had elapsed between the beheading and the moment the circulation was restored for the dog head and brain to regain much function. Guthrie recorded a series of primitive movements and basic reflexes, similar to what Laborde and Hayem had observed: pupil contractions, nostril twitchings, "boiling movements" of the tongue.[2]

The first dog heads to enjoy, if that word can be used, full cerebral function were those [of] transplantation whiz Vladimir Demikhov, in the Soviet Union in the 1950s. Demikhov minimized the time that the severed donor head was without oxygen by using "blood-vessel sewing machines." He transplanted twenty puppy heads—actually, head-shoulders-lungs—and forelimbs units with an esophagus that emptied, untidily, onto the outside of the dog—onto fully grown dogs, to see what they would do and how long they would last (usually from two to six days, but in one case as long as twenty-nine days).

In his book Experimental Transplantation of Vital Organs, Demikhov included photographs of, and lab notes from, Experiment No. 2, on February 24, 1954: the transplantation of a one-month-old puppy's head and forelimbs to the neck of what appears to be a German shepherd. The notes portray a lively, puppy like, if not altogether joyous existence on the part of the head:

09:00 The donor's head eagerly drank water or milk, and tugged as if trying to separate itself from the recipient's body.

22:30 When the recipient was put to bed, the transplanted head bit the finger of a member of the staff until it bled.

February 26, 18:00. The donor's head bit the recipient behind the ear, so that the latter yelped and shook its head.

Demikhov's transplant subjects were typically done in by immune reactions.[2]

In 1959, China announced they had succeeded in transplanting the head of one dog to the body of another twice.[3]

Dr. Vladimir Demikhov's work, among others, was deeply influential for the future science of organ transplant,[4] as he pioneered many different forms of transplant in the 1940s and 1950s, including the use of immuno-suppressants.[2] His work was well known by other scientists and during the 1950s and 1960s, numerous heart transplants were performed on dogs in the United States by Dr. Norman Shumway of Stanford University and Dr. Richard Lower of the Medical College of Virginia. The first human heart transplant was performed by Christiaan Barnard in South Africa, in 1967, however, as they did not have the chemical agents to utilize immuno-suppressants, the patient receiving the transplant did not do very well.[5]

On March 14, 1970,[6] a group of scientists from Case Western Reserve University School of Medicine in Cleveland, Ohio,[5] led by Robert J. White, a neurosurgeon and a professor of neurological surgery who was inspired by the work of Vladimir Demikhov, performed a highly controversial operation to transplant the head of one monkey onto another's body. The procedure was a success to some extent, with the animal being able to smell, taste, hear, and see the world around it. The operation involved cauterizing arteries and veins carefully while the head was being severed to prevent hypovolemia. Because the nerves were left entirely intact, connecting the brain to a blood supply kept it chemically alive. The animal survived for some time after the operation, even at times attempting to bite some of the staff.[7] In 2001, Dr. White successfully repeated the operation on a monkey.[8]

White later wrote:

…What has been accomplished in the animal model - prolonged hypothermic preservation and cephalic transplantation, is fully accomplishable in the human sphere. 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…what has always been the stuff of science fiction - the Frankenstein legend, in which an entire human being is constructed by sewing various body parts together - will become a clinical reality early in the 21st century… brain transplantation, at least initially, will really be head transplantation - or body transplantation, depending on your perspective… with the significant improvements in surgical techniques and postoperative management since then, it is now possible to consider adapting the head-transplant technique to humans.[9]

In 2002, other head transplants were also conducted in Japan in rats. Unlike the head transplants performed by Dr. White, however, these head transplants involved grafting one rat's head onto the body of another rat that kept its head. Thus, the rat ended up with two heads.[10] The scientists said that the key to successful head transplants was to use low temperatures.[11]

The ability of fusogens like PEG and chitosan to rebridge a transected spinal cord has been confirmed by a 2014 German study: paraplegic rats recovered motricity within 1 month.[12]

A human head transplant would most likely require cooling of the brain to the point where all neural activity stops. This is to prevent neurons from dying while the brain is being transplanted.

Creating a headless body

In 1996, William Shawlot and Richard Behringer of the University of Texas MD Anderson Cancer Center in Houston created 125 headless mice by knocking out a gene called Lim1 in the developing embryos. Only four of the headless embryos survived until birth, and with no nostrils or mouth to breathe through, they died immediately. Lim1 belongs to a set of genes, called the homeobox genes, that are essential to embryonic development—and that are present in all animals. Lim1, for instance, has already been found in frogs. So by studying headless mice, the researchers are finding out what goes into making a human head too. Behringer stated that the frog gene and the mouse gene are almost identical, "I would be very surprised if there wasn’t a human gene."[13]

In 1997, Jonathan Slack, professor of developmental biology at the University of Bath in southwestern England, produced the headless frog embryos by manipulating genes in frog eggs raising the possibility of growing organs for human transplantation.[14]

Planned first human head transplant

In 2013, the neuroscientist Sergio Canavero, director of the Turin Advanced Neuromodulation Group in Turin, Italy, announced the plan for the first human head transplant. Canavero states that the possibility exists to re-fuse a severed cord by use of fusogens. The project, the Head Anastomosis Venture with Cord Fusion, was announced in July 2013. He wrote:

The greatest technical hurdle to such endeavor is of course the reconnection of the donor (D)'s and recipient (R)'s spinal cords. It is my contention that the technology only now exists for such linkage. This paper sketches out a possible human scenario and outlines the technology to reconnect the severed cord (project GEMINI). It is argued that several up to now hopeless medical conditions might benefit from such procedure.[9][15]

Canavero called the procedure "Heaven surgery," shorthand for its more full name, "head anastomosis venture." He speculates that the surgery would take a team of 100 surgeons roughly 36 hours to complete, at an estimated cost of $12.8-million.[15] Dr. Canavero recently explained the rationale of HEAVEN/GEMINI at a TEDx conference.[16] He also wrote an Amazon book, Head Transplantation: and the Quest for Immortality. (CreateSpace Independent Publishing Platform, 2014), to cover the costs of the operation by crowdfunding through its sales.[17] The volunteer to receive the first head transplant is 30-year-old Valery Spiridonov, a Russian with Werdnig-Hoffman disease and rapidly declining health.[18] The procedure is planned to be performed prior 2017.[19]

Popular opinion about the potential head transplant has been generally negative, despite the claims surfacing in early 2015 that Italian neurosurgeon Sergio Canavero will be able to perform a successful head transplant, complete with a functional patient,[clarification needed] by 2017. These claims against Canavero do not take a moral or ethical stance, but rather focus on the state of technology and the time-frame in which Canavero says he will be able to successfully conduct the procedure.[20][21]

Robert J. White, the scientist who transplanted a monkey's head, became a leading target for protestors. 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 a surgeon testified in a civil hearing about Dr. Sam Sheppard's murder case, lawyer Terry Gilbert compared Dr. White to Dr. Frankenstein.[22] The People for the Ethical Treatment of Animals described White's experiments as "epitomizing the crude, cruel vivisection industry."[23]

Dr. Jerry Silver, an expert in regrowing severed nerves, stated "I think [head transplants are] fairly barbaric at this point. I do not even see that 100 years from now it is a possibility. If anybody did that today, it would be absolutely horrible. Can you imagine looking around the room, and you're just a head?"[24]

Cultural influence

See also

References

  1. ^ "The Future of Brain Transplants". NOVA. Retrieved 2012-05-11.
  2. ^ a b c Roach, Mary (2004). Stiff: The Curious Lives of Human Cadavers. W.W. Norton & Co. pp. 206–210. ISBN 0393324826.
  3. ^ "Dog-Head Transplant Claimed by Chinese". Washington Post. December 9, 1959.
  4. ^ Anna Claybourne, What Are the Limits of Organ Transplants?
  5. ^ a b Pace, Eric (November 25, 1998). "Vladimir P. Demikhov, 82, Pioneer in Transplants, Dies". New York Times.
  6. ^ Bennun, David. "Dr Robert White". The Sunday Telegraph Magazine. Retrieved 20 March 2013.
  7. ^ Laura, Putre (December 9, 1999). "The Frankenstein Factor Cleveland brain surgeon Robert J. White has a head for transplanting". Cleveland Scene.
  8. ^ "Frankenstein fears after head transplant". BBC News. April 6, 2001.
  9. ^ a b Sergio Canavero, HEAVEN: The head anastomosis venture Project outline for the first human head transplantation with spinal linkage (GEMINI),2013. Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.4103/2152-7806.113444, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.4103/2152-7806.113444 instead.
  10. ^ Young, Emma (3 December 2002). "Infant rat heads grafted onto adults' thighs". New Scientist.
  11. ^ "Head transplant possible at low temperatures". Chemistry and Industry. December 16, 2002.
  12. ^ Estrada, V., Brazda, N., Schmitz, C., Heller, S., Blazyca, H., Martini, R. and Müller, H.W., "Long-lasting significant functional improvement in chronic severe spinal cord injury following scar resection and polyethylene glycol implantation", Neurobiol Dis. July 2014, 67, pp.165-79.
  13. ^ Lori Oliwenstein, Headless Lacking a single gene, mice are born without heads, Discover Magazine, (January 01, 1996)
  14. ^ Robert Barr, Spare Human Parts Debated -- Headless Tadpoles The Latest Oddity To Spur Questions On Cloning Organs, Seattle Times, (October 21, 1997).
  15. ^ a b Rebecca Tucker (2 July 2013). "Human head transplants may be possible this century, neuroscientist says". National Post.
  16. ^ http://www.ustream.tv/recorded/52890140 - minutes 32-50
  17. ^ http://www.newsweek.com/head-transplants-gender-reassignment-surgery-gender-dysphoria-310201
  18. ^ "World's first head transplant volunteer could experience something "worse than death"". Science Alert.
  19. ^ "Human head transplants could be a reality in just two years". Science Alert.
  20. ^ Fecht, Sarah (27 February 2015). "BNo, human head transplants will not be possible by 2017". Popular Science. Retrieved 6 March 2015.
  21. ^ https://au.news.yahoo.com/technology/a/27031329/man-volunteers-for-world-first-head-transplant-operation/
  22. ^ Grant Segall, Dr. Robert J. White, famous neurosurgeron and ethicist, dies at 84, Sun News, (September 16, 2010).
  23. ^ Carla Bennett, Cruel and Unneeded, New York Times, People for the Ethical Treatment of Animals, (August 21, 1995).
  24. ^ Severed Heads 1, New Times Magazine, Page 57, (April 4, 2013).
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