An Italian doctor says he's ready to perform a controversial human head transplant, using what he's learned from a successful procedure on animals in China. The announcement of the ground-breaking operation is raising ethical and scientific questions. Paolo Montecillo has this story.

An 18-hour surgical procedure on dead bodies served as a practice run. Now one doctor is confident head transplants can be done on the living. Italian doctor Sergio Canavero says his team is ready to put one person's head onto the body of another. The shocking claim is making headlines around the world. Canavero bases his optimism on research conducted by Professor Ren Xiaoping of Harbin Medical University. The Chinese team has been successful in performing head transplants on mice and monkeys.

PROF. REN XIAOPING HARBIN MEDICAL UNIVERSITY "The head transplant is the last and greatest challenge of human medical science. We've never confronted it before."

The medical community is almost universally opposed to human head transplants. A professor from Sweden's Karolinska Institute has described Sergio Canavero as a 'criminal'. An expert from the American Association of Neurological Surgeons, won't allow this type of procedure under his watch.

Valery Spiridonov, a Russian computer engineer who suffers from congenital Spinal Muscular Atrophy, had originally agreed to undergo the controversial procedure.

VALERY SPIRIDONOV COMPUTER ENGINEER "Doing this is not only an excellent opportunity for me, but will also create a scientific basis for future generations. No matter what the actual outcome of the surgery is."

However, he's since backed down from the idea, and chosen to accept traditional therapy instead. Medical experts have questioned both the science and the ethics behind the concept. Many say the procedure is fraught with danger and profound questions about the identity and rights of the recipient. But Ren is confident that human transplants are on the horizon.

REN XIAOPING "Fifty years ago, there was a huge debate ahead of the first heart transplant. Even the first hand transplant 20 years ago faced ethical concerns. The impact of head transplant will be even greater. "

A successful head transplant for humans may well be in the near future. But it's clear there are bigger questions to wrap one's head around.