"Head transplantation, body transplantation, whatever"

Earlier this year, Sergio Canavero became famous around the world when he enlarged on plans, long cherished, to remove the heads of two people. One would be alive, with an ailing body (a paraplegic, say), the other newly dead or doomed (perhaps the brain-dead victim of an accident). As Canavero explained in academic papers and speeches, he planned to surgically attach the first head to the second body, fusing the spinal cords so that the owner of the first head might enjoy the functional use of the second body. It might be best understood as a "body transplant," but the wider world has tended to settle on the more sensational phrase.

...his operation will be ready to go sooner than anybody might have expected — as early as Christmas 2017, he thinks.

Canavero has a very clear picture of this surgery in action, having outlined it in two TED talks, in a keynote address last summer at an American conference of neurosurgeons, and in a new book, Il Cervello Immortale ("The Immortal Brain"). He describes it to me in detail: the operating theater of the near future, where two bodies will be clamped tight in special frames. One will be the anesthetized patient; the other, a brain-dead donor. Using either "a specially fashioned diamond microtomic snare-blade" or "a nanoknife made of a thin layer of silicon nitride" (he isn't sure yet), the bodies will be severed at the neck between the C5 and C6 vertebrae. Then the frames that are clamping the two bodies will begin to separate, their upper parts rotating and taking the two heads with them. The patient's head will be deposited atop the donor's body.

Next, a marathon of surgery, somewhere between 36 and 72 hours long and requiring a crew of 150 medics. About 80 of them, Canavero thinks, will need to be surgeons. "At first, it will be expensive" — around $17 million, he guesses, admitting that private sponsors are still needed. "Later, as the technique gets perfected, the costs will be slashed." In the operating room, those 80 surgeons will relay in and out as expertise dictates. The head-body arteries will be joined first, so that blood recirculates around the brain. As for the other connections required (windpipe, gullet, spine, everything that links a human's head to the rest), Canavero says he will stand aside until it comes to the spinal cord. Functional neurosurgery, or that relating to movement, is his field.

..."Heart transplants, kidney transplants: all were based on years and years of animal work," says the eminent British neurosurgeon Henry Marsh. Many of those who are skeptical about Canavero's scheme, Marsh among them, have wondered: Where are his carcasses?

...When it comes to the implications of all this, Canavero doesn't really consider them to be his problem. Scientifically, "what can be done, will be done." All he feels obliged to do is encourage other people to ponder the implications. If we are to live longer, for instance, what about overpopulation? He guesses we'll have to think about conquering other planets. When I ask how there will be enough bodies to support all the transplants, he says, "Cloning will come into play." I must show my exasperation, because he looks at me with concern. "I know it's hard," he says. "It's hard to swallow, I understand that, it's crazy. Sometimes, when I look at it, I say, ‘Will mankind be able to handle this?' I don't know! But society must prepare itself for a major tectonic shift."

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