Italian neuroscientists propose a head transplant to turn science fiction into reality

According to British media reports, an Italian neurologist recently announced that he will be in two years of the world's first complete human head transplant, the past only in science fiction and horror films of the plot into reality.

If this pioneering transplant becomes a reality, then a patient like Hawking is likely to get a new life.

Cost 7.5 million pounds

The Daily Mail of the UK reported 25th that the plan was made by Sergio Canavillo, an expert in neurosurgery at the high-level neuro-regulatory group in Turin, Italy. He believes the transplant requires 100 surgeons to continue for 36 hours and spend 7.5 million pounds. The surgery is for patients who are paralyzed by spinal injury or suffering from severe muscular atrophy, such as the late "Superman" actor Reeve and physicist Hawking.

Canavillo said he would announce his head transplant program at a high-level medical conference this summer ——— the first head transplant in 2017.

"The biggest technical obstacle (head transplant) is undoubtedly reconnecting the donor and the receptor of the spinal cord." I believe that the technology for this type of connection is now in place. Canavillo said in his paper.

In addition, Canavillo prepared a list of alternative patients, the location of the operation is inclined to London, England.

Learn to walk within a year

Critics argue that Dr. Kanak's vision is too crazy to be "pure fantasy". But Karnak argues that the current medical technology is enough to support the entire operation, and that all he needs to do is integrate the technology.

According to the newly published New Scientist magazine, the first case of surgery was from a brain-death patient. The key to the operation is to cut off both the donor and the receptor's neck tissue and spine, and cleanly cut off the head and body.

Canavillo explained in the article that the bone marrow must be severed with a sharp scalpel and "mechanically connected" to other bodies. He further explained: "This clean and decisive cutting is the key to the fusion of bone marrow, which allows the proximal axon to fuse with the distal axon." ”

The next step is to quickly transplant the patient's head into the donor's neck, using a medical "glue" to connect the spine together. The muscles and blood vessels are then stitched together, and the patient is unconscious for up to 4 weeks after the surgery to heal as close as possible. In the process, the Doctor also uses a weak current to stimulate the nerves inside the cervical spine, strengthening the head and body connections.

Once the surgery is successful, the patient will learn to walk within a year with the help of physiotherapy and learn to adapt to his new body, including feeling the face, even speaking with the original voice, Canavillo said.

At the same time, doctors will use powerful immunosuppressive drugs to inhibit the new body's rejection of the head.

Ethical controversy continues

But there are still ethical controversies surrounding head transplants.

Canavillo said a head transplant may be the only "moral" option when paralyzed patients have no other way. But opponents say that even if the surgery is successful, who is the patient who gets the recovery? Biologically, will the offspring of the new body come from donor or receptor?

In addition, William Mar Matthews, President of the American Academy of Neurological and Orthopaedic surgery, argues that two years is too hasty for the complex operation of a head transplant.

"I agree with the medical concept of spine fusion, which requires a lot of work, but I don't agree with Dr. Karnak's timetable," says Matthews, "he (Canavillo) thinks everything is ready, but it seems to me there is a long way to go." ”

California doctor Harry Godesmith, who has repeatedly successfully treated patients with spinal injuries, is optimistic about the idea of head transplants.

"I don't think it will ever happen." "he said.

Process

Critical steps completed in one hour

Canavillo has published a paper in the academic journal Neurosurgery International, detailing the process of transplant operations.

First, the head and body used for transplants will be cooled to around 12 degrees Celsius to 15 degrees Celsius to slow cell death rates. Then the neck of the patient and donor is cut off at the same time, and the large vessels are connected by artificial blood vessels. Then cut the cervical vertebrae. The process must be completed in an hour, because one hour is the longest time the human brain can survive without the steady flow of blood and oxygen.

The next step is to connect the head of the patient to the body of the donor. In this process, the key link is to connect the nerves of the cervical spine tightly. Canavillo plans to combine donor and receptor machinery with plastic such as polyethylene glycol (PEG). He theoretically explained that a clean cut and tight fusion would allow the body to naturally repair the severed nerves.

Once the head is reconnected, the recipient's heart can be restarted.

History

More animal trials end in failure

The researchers had previously had a head transplant, most notably in a 1970 trial with macaques.

Dr. Robert White, the American neurosurgeon, successfully transplanted the head of the macaque to another macaque in 1970. In the 2001, doctors in the United States performed a similar operation that allowed them to sniff, open their eyes and taste food. But it turns out it's hard to connect a central nervous system. In experiments with macaques, many organs run smoothly, but are paralyzed from the neck, because the spine is not properly connected. Eventually, the animals were soon paralyzed and died several hours after the operation.

Researchers at the University of West Reserve and the Cleveland Clinic in the United States have managed to restore important control functions in rats with spinal cord transection. The surgery is similar to the 1970 operation: lowering the body temperature as low as possible, inducing cardiac arrest, and then reconnecting as much as possible. The connection to the circulatory system is relatively easy, but this operation restores neurological functions for the first time. The way to connect the spinal cord is to use the nerve fibers in the rat's chest to make a similar scaffold, and then fix it with fibrin. Blood fibrin is a protein that induces coagulation in the blood. The researchers used a small amount of chemicals to speed up the process to achieve the desired effect, using chondroitin ABC to prevent scar formation and to promote nerve growth with fibroblast cells.

6 months later, rats regain bladder control, but they never regain the ability to walk. As Canavillo points out, this is a big step forward. (Tanguizhi)