A surgeon who claims to perform the world’s first head transplant operation next year has released a series of videos showing paralyzed animals being “cured” by his groundbreaking technique.
The video shows mice, rats and dogs that can walk.
A few weeks earlier, their spinal cords had been severed and the ends treated with chemicals that may help them heal again.
The study was conducted by Korean researchers in collaboration with Italian neurosurgeon Dr. Sergio Canavero.
He said the experiments proved that spinal cord reconstruction was possible, paving the way for head transplants into paralyzed people.
Other scientists have rejected the claims, saying the numbers of treated animals were too small to provide sufficient evidence.
The Korean researchers detailed their experiments in a series of papers in the International Journal of Surgical Neurology, edited by Dr. Canavero.
Volunteer patient Valery Spiridonov meets neurosurgeon Sergio Canavero for the first time. Photo: Provided
In the first experiment, the spinal cords of 16 mice were severed.
Half of the patients then had a chemical called polyethylene glycol (PEG) injected into the spaces between the severed nerve fibres, while the rest had a saline solution.
Five of the mice that received PEG regained some movement, suggesting that the chemical helped severed nerve fibers fuse together, allowing signals from the brain to reach the limbs again.
In the second experiment, PEG was combined with tiny graphene ribbons that the researchers claim would act as “tracks” to ensure that both ends of the spinal cord grew towards each other.
Rats treated with the combination were able to walk again after two weeks.
In the final experiment, 90% of the dog’s spinal cord was severed, causing damage similar to that caused by a stab wound in a human.
Three days after PEG treatment, the dog regained minimal movement.
Valery Spiridonov (centre), who suffers from Werdnig-Hoffmann disease, volunteered to be the first patient to undergo a head transplant performed by Dr Canavero. Photo: Maxim Zmayev/Reuters
After three weeks he was walking and soon began wagging his tail.
The experiment is being prepared for Dr Canavero’s first human patient, Russian program manager Valery Spiridonov, who suffers from the rare muscle-wasting disorder Werdnig-Hoffmann disease.
The 31-year-old volunteered for the transplant and said he was willing to risk his life to escape the disease.
The transplant will be performed in a vegetative state and is scheduled to take place at Harbin Medical University in China.
What happens during the procedure
This two-part surgery consists of HEAVEN (head anastomosis surgery) and Gemini (subsequent spinal fusion surgery).
The entire process will take 36 hours, 150 people (doctors, nurses, technicians, psychologists, virtual reality engineers) and about $20 million.
According to Dr Canavero, two surgical teams will be working simultaneously on the Russian patient.
One focuses on the living patient, Mr Spiridonov, and the other on the donor’s corpse.
Donors are brain-dead and selected based on their height, build and immune type.
Valery Spiridonov, who volunteered to be the first patient to undergo a head transplant, is assisted before a press conference in Russia in 2015. Photo: Maxim Zmayev/Reuters
Sergio Canavero demonstrated his head transplant technique at a conference in 2015, using a banana as a spinal cord. Photo: Provided
Both patients will be anesthetized and attached to breathing machines and electrodes to monitor brain and heart activity.
Spiridonov’s brain then nearly freezes, rendering him temporarily brain dead.
At this point, the doctor will drain the blood from the patient’s brain and flush it with surgical fluid.
Tubes are wrapped around major arteries and veins to stop blood flow, and then once the new body is attached, the tubes are removed to allow blood to circulate.
Then they cut the most important parts – both spinal cords.
This will be done using $200,000 diamond nanoblades provided by the University of Texas.
If Spiridonov’s head were to separate from his body, he would need a new body within the hour.
All the necessary arteries and veins were reconnected and, in theory, the new blood flow would help rewarm Spiridonov’s head.
To begin the operation, the body and head are frozen to a temperature that will not kill cells if they are starved of oxygen during the operation, rendering the patient temporarily brain dead. Photo: AP
Ultimately, a $200,000 diamond nanoblade was used to cut both spinal cords, allowing the patient’s head to be removed from his body. Photo: Provided
From there, the pieces of spinal cord are then healed in yet another novel surgery, and all the severed muscle and skin are sewn back together.
If all goes according to plan, Spiridonov will be able to stand and walk three to six months after the surgery.
“If he dies, that’s the decision he can make,” Dr. Canavero said.
The operation is currently scheduled to take place late next year, meaning the patient could take 12 months to recover.