Italian surgeon Dr. Sergio Canavero made headlines earlier this year when he announced plans to conduct the world’s first human head transplant within two years. Now, a 30-year-old Russian man is set to become the first person to undergo the procedure.
Dr. Canavero, of the Turin Advanced Neuromodulation Group (TANG) in Italy, first spoke of his plans to carry out the first human head transplantation in July 2013 – a project named HEAVEN-GEMINI.
At the American Academy of Neurological and Orthopedic Surgeons’ 39th Annual Conference in Annapolis, MD, in June, Dr. Canavero will present updated plans for the project, addressing some of the previously identified challenges that come with it.
Though researchers have seriously questioned the feasibility of Dr. Canavero’s plans, it seems the first human head transplantation is a step closer to becoming a reality with the news that Valery Spiridonov, a 30-year-old computer scientist from Vladimir, Russia, has volunteered to become the first person to undergo the procedure.
Spiridonov has Werdnig-Hoffman disease — a rare genetic muscle wasting condition, also referred to as type 1 spinal muscular atrophy (SMA). The condition is caused by the loss of motor neurons in the spinal cord and the brain region connected to the spinal cord. Individuals with the disease are unable to walk and are often unable to sit unaided.
Spiridonov was diagnosed with Werdnig-Hoffman disease at the age of 1 and told the Daily Mail that he volunteered for HEAVEN-GEMINI because he wants the chance of a new body before he dies. ‘”I can hardly control my body now,” he said. “I need help every day, every minute. I am now 30 years old, although people rarely live to more than 20 with this disease.”
Donor body will be attached to recipient’s head through spinal cord fusion
Dr. Canavero told CNN he has received an array of emails and letters from people asking to be considered for the procedure, many of which have been from transgender individuals seeking a new body. However, the surgeon says the first people to undergo the procedure will be those with muscle wasting conditions like Spiridonov.
The procedure Dr. Canavero outlines is very much like that used by Robert White, who successfully transplanted the head of a rhesus monkey onto the body of a second rhesus in 1970. First, both patients must be in the same operating theater. Then the head to be transplanted must be cooled to between 12°C and 15°C (54.6°F and 59°F). Moving quickly, surgeons must remove both heads at the same time, and re-connect the head to be preserved to the circulatory system of the donor body within one hour. During the reconnection procedure, the donor body must also be chilled, and total cardiac arrest must be induced.
Once the head is reconnected, the heart of the donor body can be re-started, and surgeons can proceed to the re-connections of other vital systems, including the spinal cord.
It is the next step — fusing the spinal cord — that is the most complicated and unprecedented piece of the surgery, which is projected to take 100 surgeons around 36 hours to complete. As Dr. Canavero explained in a 2013 paper:
“The greatest technical hurdle to [a head transplant] is of course the reconnection of the donor’s (D)’s and recipients (R)’s spinal cords. It is my contention that the technology only now exists for such linkage…. [S]everal up to now hopeless medical connections might benefit from such a procedure.”
Connection of a spinal cord from the head of one creature to the body of another has never been attempted even in animals, although the severing and re-connection of spinal cords in the same animal has met with limited success in the past. In 2013, scientists at Case Western Reserve University and the Cleveland Clinic were able to restore limited connectivity between the two severed halves of spinal cords in rats.
The re-connection of spinal cords can be accomplished through the encouragement of the body’s natural healing mechanisms, which are at work even in the severed spinal cord. But Dr. Canavero’s proposal is different: By cutting spinal cords with an ultra-sharp knife, and then mechanically connecting the spinal cord from one person’s head with another person’s body, a more complete (and immediate) connection could be accomplished, while also limiting damage to the spinal cord.
“The key to SCF is a sharp severance of the cords themselves,” Dr. Canavero explains in a paper published earlier this year, “with its attendant minimal damage to both the axons in the white matter and the neurons in the gray laminae. This is a key point.”
Canavero hypothesizes that plastics like polyethylene glycol (PEG) could be used to accomplish this fusing, citing previous research showing that, for example, in dogs PEG allowed the fusing of severed spinal cords.
After the initial surgery, recipient will be kept in a coma for around 3-4 weeks, says Dr. Canavero, during which time the spinal cord will be subject to electrical stimulation via implanted electrodes in order to boost the new nerve connections. The surgeon estimates that, with the help of physical therapy, the patient would be able to walk within 1 year.
Spiridonov admits he is worried about undergoing the procedure. “Am I afraid? Yes, of course I am,” he told the Daily Mail. “But it is not just very scary, but also very interesting.”
“You have to understand that I don’t really have many choices,” he added. “If I don’t try this chance my fate will be very sad. With every year my state is getting worse.”
Dr. Canavero branded ‘nuts’
Dr. Canavero has previously admitted there are two major challenges with HEAVEN-GEMINI: reconnecting the severed spinal cord, and stopping the immune system from rejecting the head. But he claims that recent animal studies have shown the procedure is “feasible.”
Unsurprisingly, however, researchers worldwide are highly skeptical of the proposal. Speaking to CNN, Dr. Arthur Caplan, PhD, director of medical ethics and NYU Langone Medical Center in New York, NY, even called Dr. Canavero “nuts.”
Dr. Caplan said the procedure needs to be conducted many more times on animals before it is applied to humans, adding that if the technique is feasible then Dr. Canavero should be trying to help paralyzed patients before attempting whole body transplants.
And in an interview with New Scientist earlier this year, Harry Goldsmith, a clinical professor of neurosurgery at the University of California-Davis, said the project is so “overwhelming” that the chances of it going ahead are unlikely.
“I don’t believe it will ever work,” he added, “there are too many problems with the procedure. Trying to keep someone healthy in a coma for 4 weeks – it’s not going to happen.”
Spiridinov said he is well aware of the risks and, despite Dr. Canavero’s many detractors, he trusts the surgeon to carry out the 36-hour operation, which touts an estimated cost of $13 million USD.
“He’s a very experienced neurosurgeon and has conducted many serious operations. Of course he has never done anything like this and we have to think carefully through all the possible risks,” he told the Daily Mail. But, he added, “if you want something to be done, you need to participate in it.”
Though it not been confirmed when the procedure will be performed, Spiridonov says it could be as early as next year. He said he wants to take his chance at having a healthy body before he dies. “My decision is final and I do not plan to change my mind.”