Sometime in the next two years, if a plan conceived by Dr. Sergio Canavero comes to fruition, the following medical first will happen: In a surgical facility in Harbin, China, a living patient with a irreversibly dying body, and the body of a recently deceased donor — one whose fatal injuries were above the neck — will be wheeled into a specially-equipped operating room, where teams of surgeons will go to work. Doctors will cool the body of the living patient, putting him in a state of medically-induced hypothermia, and also cool the headless donor body to keep its cells and organs alive. Then they'll sever the living patient's head.
The still-living head will be quickly strapped into a specially customized crane, which will whisk it across the room to the table where the donor body is waiting. Surgeons will then align the severed stump of the donor head's spinal cord with the donor body's spinal stump, and bind the two together with polyethylene glycol, which will serve as a glue. Then they'll start a long, difficult process of attaching and matching up neck muscles, spinal bones, and organs such as the esophagus and trachea. Finally, they'll try to connect the nerves that transmit signals from the brain to the heart and lungs, so that the head-and-body combination can breathe and regulate its own heartbeat.
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This head transplant might sound like the plot premise of a particularly outlandish science fiction thriller. But in an email to HowStuffWorks, Canavero, who published a 2013 medical journal article describing the procedure, says he is confident that the operation has a high chance of success.
"I am convinced that someday in the near future the first human head transplantation will be possible because surgical research will be able to solve the last medical problems to make it happen," he wrote. "I think that in 2017 or 2018 [at] the latest, we should be able to perform the surgery."
Canavero is working with a Chinese colleague, Dr. Xiaoping Ren, who assisted in the first-ever human hand transplant in 1999. In a 2014 article in the journal CNS Neuroscience and Theraputics, Ren described experimental head-to-body transplants that he has performed with mice. According to New Scientist, Ren also recently carried out a partial head transplant on a monkey, connecting the blood supply but not the spinal cord. The animal survived for 20 hours before being euthanized.
The idea of head transplants is far from new. Back in 1959, a Russian surgeon, Dr. Vladimir Demikhov, performed an experiment in which he grafted a puppy's head, shoulders and paws onto the shoulder of a larger dog. In 1970, American surgeon Dr. Robert White attached a monkey's head to another monkey's body, and co-wrote this 1971 medical journal article about the experiment.
But no one has ever tried performing such an operation on a human being. Nevertheless, according to multiple media accounts, a 31-year-old Russian software entrepreneur who suffers from a genetic disorder that has destroys muscles and nerve cells, reportedly has volunteered to be the subject.
The publicity about the plan has aroused a storm of criticism. Some experts think it has little, if any, chance of success.
"We do not yet have the means/technology for the surgically attached brain and upper spinal cord (the head) to reconnect neurologically with the new body and lower spinal cord," Dr. John Adler, a neurosurgeon and professor emeritus at Stanford University's School of Medicine, says via a email. "Therefore, the brain would not 'control' the body to which it was attached.".
It's a tricky procedure for sure, as our Fw:Thinking colleagues explain in this audio podcast:
Arthur Caplan, founding head of the Division of Bioethics at New York University Langone Medical Center, says, "I think the science is not there." Caplan, who wrote a scathing critique last year of Canavero's proposal, said that a head-to-body transplant is simply too extreme of an experimental leap. "The key element is getting a spinal cord to regrow," he explains. "If you could do that, why not demonstrate it before you move on to transplanting severed heads?"
Caplan says that such a head-to-body transplant would be unlikely to meet the approval of ethics committees at U.S. medical institutions, and that the fact that someone is willing to be a subject isn't sufficient justification for the experiment. "A patient is coerced by his disease, and not qualified to judge where the science is," he says.
For their part, Canavero and Ren, in a 2016 medical journal essay defending their proposal, argued that head-to-body transplants are a justifiable option to explore because medicine so far has failed to find cures for many diseases.
"For the longest time medicine has failed to find solutions for spinal damage," Canavero said in his email. A head-to-body transplant, he said, "could solve a lot of those problems." He boldly predicted that if successful, the experiment might "revolutionize medicine entirely and become one of its finest hours."
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