A head transplant is a surgical operation involving the grafting of an 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.
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 many different and difficult transplant surgeries. It may also be useful for people who would rather be quadriplegic than dead. There is no uniform consensus on the ethics of such a procedure.
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 man-made 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.||
|“||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.
In 1959, China announced they had succeeded in transplanting the head of one dog to the body of another twice.
In 1963, a group of scientists from Case Western Reserve University School of Medicine in Cleveland, Ohio, 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.
Other head transplants were also conducted recently 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. The scientists said that the key to successful head transplants was to use low temperatures.
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. Ethical considerations have thus far prevented any reported attempt by surgeons to transplant a human being’s head.
Future and stem cells
Through medical science, it is now known that stem cells are capable of specializing into any type of cell found in the human body. In 1998, Fred H. Gage of the Salk Institute in La Jolla, California, showed that new, functioning neurons are indeed capable of being grown in the human hippocampus. Historically, this was thought to be preposterous. The news gives a ray of hope for individuals suffering disabling diseases. Most believe the key to helping individuals whose bodies are incapable of sustaining them is not through arguably crude operations like a head transplant, but through stem cell research. However, the tenet of head transplantation may become more popular, as stem cells have been shown by the Wistar Institute of the University of Pennsylvania to repair the severed spinal cords of mice to a functional level. This could mean the subject would no longer be condemned to quadriplegia.
Should the technology to repair the damage to the spinal cord be developed, the possibilities of what a head transplant could accomplish would become endless. A disease such as cancer (non-brain) which afflicts an area of the body such as the lung or bladder, as well as other diseases such as diabetes which affects the pancreas and heart disease, could be cured through the transplantation of the head. People with genetic diseases such as muscle dystrophies whose bodies lose more and more functions over time, eventually leading to death, could benefit greatly from this procedure. These diseases all affect the body but not the head. Should the head be transplanted, these afflictions would be left behind in the old body, while the new body would enable the head transplant donor (not recipient, unless legal identity is carried with the body) to live a longer, healthier life. This would ultimately serve to improve the standard of living for the donors (or recipients) and could potentially double their life spans. Of course, the issue of immune rejection would, however, need to be addressed as always. Ethical concerns might well persist even if function could be completely restored to the patient: a brain dead person with a healthy body, suitable for head transplantation, is automatically in great demand as an organ donor. When used as a head transplant recipient, a body which might have prolonged and enhanced several lives is instead used for the benefit of a single person. Such an outcome will be unacceptable to health systems which suffer from a shortage of organ donors, or could suffer consequent to widespread adoption of head transplantation. Using, where possible, the functional organs of the diseased surplus body, may partially alleviate this concern.
In 1998 Charles Krauthammer of Time magazine warned of the potential medical future of head transplanting with cloning:
|“||At the University of Texas and at the University of Bath. During the past four years, one group created headless mice; the other, headless tadpoles. Why then create them?…Take the mouse-frog technology, apply it to humans, combine it with cloning, and you are become a god: with a single cell taken from, say, your finger, you produce a headless replica of yourself, a mutant twin, arguably lifeless, that becomes your own personal, precisely tissue-matched organ farm…Congress should ban human cloning now. Totally. And regarding one particular form, it should be draconian: the deliberate creation of headless humans must be made a crime, indeed a capital crime.”|