Why A Head Transplant Probably Isn't Happening Any Time Soon

PHOTO: Illustration of overlapping profiles of a mans head.Getty Images
Illustration of overlapping profiles of a man's head.

An Italian scientist has been making headlines after claiming that he believes he will be able to perform a successful human head transplant in just a few years. But experts say it’s unlikely the procedure will happen anytime soon.

Dr. Sergio Canavero, director of the Turin Advanced Neuromodulation Group, Turin, Italy, has proposed in two published medical articles that a head transplant is possible thanks to new technology that allows for the body to be cooled during surgery, a tools that create a cleaner cut on the spinal cord and machines that allow people to be on bypass during surgery.

At a recent conference in Maryland, Canavero told surgeons he wanted to perform the procedure in December 2017 and met a patient willing to consider the operation, according to Reuters.

The surgeon told Reuters that he believed that there was a "90 percent" chance that the surgery would work.

But it’s likely that Canavero’s dream of performing the surgery is more than just 18 months away due to the fact that in the papers where he has presented his idea, he has not given any evidence that this procedure will work long term by showing it works in animals.

Dr. Michael DeGeorgia, a neurologist at University Hospitals Case Medical Center, said in order for Canavero to ethically and possibly legally perform the procedure on a human he would have to show that the process works in animals and present those findings to peers before getting to try out the procedure on a human.

“You go through normal progress and no matter how painful and slow that is,” said DeGeorgia. “So that it’s not just valid in petri dish but in an animal…[see] if it works and what are the side effects and can we actually perfect it.”

Canavero has pointed to a 1970 operation where a surgeon at Case Western Reserve Medical Center transplanted the head of one rhesus monkey to another, as a reason the operation might work. The animal survived for 10 days on a ventilator before eventually dying, according to DeGeorgia.

Although Canavero points to that 1970 operation as a sign that he could be successful, DeGeorgia said that the operation doesn’t reveal that the procedure would work on a human, or even have long term success in an animal.

“Dr. Canevero talks about in his patients but we’re not quite ready for prime time even in animals,” said DeGeorgia.

DeGeorgia explained that one major issue is how to safely separate and reattach the spinal cord. While Canaverso said a specific substance could be used to help preserve the spinal cord, DeGeorgia said it’s only been tested in petri dishes.

“It’s never been done in animals let alone in humans and putting the whole package together has never been done,” said DeGeorgia.

DeGeorgia admits the new technology means a surgeon would likely be able to successfully reattach the vascular areas of veins, which was also successfully done in the 1970 operation, but that it’s unclear whether the brain would survive the operation. Additionally, the immune system could attack the transplanted material, creating a fatal problem.

“The bigger issues are rejection [and] the immunological consequences of the transplant,” said DeGeorgia.

Another issue is the fact that the spinal cord doesn’t just tell limbs to move your lungs to breathe, it also sends millions of tiny signals to the body that regulate everything from appetite to the immune system.

“That’s the issue, there’s millions of little nerve endings that are keeping everything in the right balance,” said DeGeorgia. “How would that work? It may not work so well.”

While Canavero’s proposal seems like science fiction — and does not offer much proof it could work — DeGeorgia admits that the surgery may not be as far-fetched as it seems.

“I’m as skeptical as everybody but you can’t completely dismiss the concept,” said DeGeorgia. “If you said in the 1940s and we’re going to take someone’s heart and put it into someone else’s body they would have thought you were crazy.”

However, DeGeorgia said there is almost no chance that Canavero reaches his goal of performing a successful procedure by 2017.

“I think it’s not going to be in two years or even 10 or 20 years,” said DeGeorgia.