According to a paper published in the journal Surgical Neurology International, the technology is now available to perform a procedure that is technically known as a cephalosomatic linkage.  In lay terms, that means a head transplant.  The paper, authored by Italian neurosurgeon Sergio Canavero, walks through the hypothetical procedure, which he has named HEAVEN.  Canavero builds on the 1970 work of Robert White, which successfully transplanted the head of a rhesus monkey onto the body of another.

When White transplanted the head onto the monkey, the monkey lived for eight days without identifiable complications. A similar procedure was carried out in 2001.  This time, the monkey was able to open its eyes, taste, and smell.  However, the spinal cord could not be reconnected, leaving the monkey paralyzed.  The monkey died within a few hours of the procedure.

Project HEAVEN identifies the need for a hypothermia protocol, initial separation of the head, and connection of the spinal cord.  Canavero recommends keeping the head cooled because mammals can survive without blood flow for up to one hour when kept at temperatures below 20 degrees Celsius.  In separating the head, the recipient must be sedated, tracheotomatized, and put on mechanical respiration.  For reconnecting the spinal cord, Canavero notes that it may be possible to use polymers to help fuse and seal.

Theoretically, this procedure offers a chance for a new body for paraplegics of quadraplegics.  It could also be used for other conditions that are atrophying the body, without the brain being affected.  The estimated cost of the surgery is $13 million, making it an even more distant reality.

Clearly, such a procedure would be complicated and risky.  Dr. Jerry Silver, a scientist who worked with White on the rhesus monkey head transplant, criticizes the assertions of Canavero.  Silver believes the technology has not developed anywhere near where it needs to be for successful spinal cord reconnection.  Moreover, Silver argues that this procedure is bad science and the experiments needed to develop it are unethical.  He recounts his days working with White, and the pain and anxiety seen in the face of the monkey.

Whether or not such a procedure will actually be attempted remains to be seen.  The use of animals in research is regulated under the Animal Welfare Act.  There are also efforts to increase the amount of protections given to animals, though the regulatory action remains stalled.  Advocacy groups are likely to try and stop further head transplant experimentation.