frontiers

Could Anyone Really Transplant a Head?

Dr. Sergio Canavero says his team will be able to swap out an entire human body by 2017.

Dr. Sergio Canavero swears there’s nothing pretend about his plan to put the head of Valery Spiridonov, a Russian with a muscle-wasting disease who has volunteered himself as a test subject, on the body of a newly dead donor. Canavero claims to have solved the problems his hero, Dr. Robert White, met in 1970, when he got a monkey’s head to live (briefly) on a new body (that couldn’t move). Canavero now says he and a team of 150 will be able to swap out an entire human body by 2017, and he has promised to reveal the details in mid-June. We asked experts to consider the many, many obstacles he faces.

The Spinal Cord
The cut Canavero proposes — at vertebra C5 or C6 — must be ultraclean yet incredibly gentle. Then, he says, he’ll stick the spinal cord together with polyethylene glycol, a compound found in everything from toothpaste to paintballs. “We’re not even close to realizing that,” explains Michael Fehlings, a neurosurgeon who calls the idea “fanciful.” (Last year in China, a team tried it on mice. The mice died within hours.) “Even if there is a clean cut,” adds Jerry Silver, a Case Western neuroscience professor, bleeding will create “a huge immune response,” damaging tissue fast. Silver watched White perform the monkey surgery, and recalls it as “just awful.”

The Neck Structure
Eduardo Rodriguez, a reconstructive plastic surgeon at NYU Langone who’s done one of the most extensive face transplants to date, says the crosscut will be a mess: The spine is like a cable with fibers “that you have to realign correctly so they transmit to the right place and connect in the right orientation.” And the esophagus and trachea are like onions, with multiple layers, each requiring its own sets of sutures.

The Vascular System
Canavero would have at most an hour to get blood flowing again. (He’s proposed cooling the head to around 55 degrees Fahrenheit to slow brain death.) Vascular neurologist Neil Schwartz says that it’s hard to imagine even four or more surgeons (“There’d be a limit to how many could get in there at once”) reconnecting everything in time.

The Parasympathetic Nervous System
The vagus nerve (which would be hard to re­attach) controls a lot — digestion, speech, sweating. The patient would have “no control of heart rate, which will skyrocket,” says Silver. “The life of such a patient — for as long as life could persist — would be several orders of magnitude worse than that of Christopher Reeve.”

The Respiratory System
The diaphragm won’t contract without “well-coordinated input” from above the incision, Schwartz notes. He doubts a patient would emerge breathing, and most likely wouldn’t be able to coordinate breath with speech or swallowing.

The Mind
“The brain is not contained in a bucket,” says Art Caplan, director of medical ethics at NYU Langone. “It integrates with the chemistry of the body and its nervous system. Would a brain integrate new signals, perceptions, information from a different body? I think the most likely result is insanity or severe mental disability.” NYU’s Rodriguez says psychological issues, more than physical ones, are a limiting factor with face transplants. “And that’s just a face.”

The Whole Head
All transplants require immunosuppressive drugs — and who knows the dose a head would require, says Caplan. It could also end up “being overwhelmed with different pathways and chemistry” and simply “go crazy.”

*This article appears in the June 8, 2015 issue of New York Magazine.

Could Anyone Really Transplant a Head?