A head transplant is a surgical operation. It is 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.[1]
A head transplant is a surgical operation. It is 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.[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 many different and difficult transplant surgeries. Quadriplegia may be an acceptable option for the terminally ill. There is no uniform consensus on the ethics of such a procedure.[2]
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In 1959, China announced that it had succeeded in transplanting the head of one dog to the body of another twice.[3]
On March 14, 1970,[4] 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.[6]
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.[7] The scientists said that the key to successful head transplants was to use low temperatures.[8]
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.
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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. This was previously thought to be impossible. The news gives some hope to 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 techniques developed through stem cell research. However, the concept 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 restricted to quadriplegia.
Should the technology to repair damage to the spinal cord be developed, there are many possibilities of what a head transplant could accomplish. 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 it would with other forms of organ or body transplantation. Ethical concerns might persist even if function could be completely restored to the patient: a brain-dead person with a healthy body, suitable for head transplantation, would be 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 2013, Dr Sergio Canavero, director of the Turin Advanced Neuromodulation Group in Turin, Italy, announced the plan for the first head transplant in man. According to data accrued over the past 15 years, the possibility exists to re-fuse a severed cord by use of so-called fusogens (e.g. PEG). The project has been released in the June issue of Surgical Neurology International (www.surgicalneurologyint.com).