Head transplant: details
Sergio Canavero announced a successful "rehearsal" of a human head transplant
Maxim Agadzhanov, Geektimes
The Italian surgeon Sergio Canavero has not been heard from since the (partial) head transplant of a rat. Very little news has been published for a long time. But the other day, Canavero said that the first successful human head transplant was carried out in China. Many media outlets have published a description of the operation under such headings. But in fact, we are talking about transplanting the head of a corpse onto a dead body. This operation is stated as a "rehearsal" for the transplantation of a conditionally living head onto a conditionally living body.
Canavero said that the operation was carried out by a team of Chinese surgeons led by Ren Xiaoping, who in 2016 carried out similar work with the body and head of a monkey. Then it was not entirely clear what had happened. Scientists announced the transplantation of the monkey's head. The composite creature (body + head) had to be euthanized after 20 hours for some "ethical reasons". The operation itself was declared as conditionally successful. Now the transplantation of a corpse's head is described in about the same way. Canavero claims that the Chinese managed to transplant the head by connecting nerve endings and blood vessels, even if they were dead. The Italian claims that the operation went as planned.
For an ordinary person, such news looks quite plausible. Indeed, doctors have already learned how to transplant many organs, including the heart. And not only the heart. Successful face, penis, uterus and even hands transplants are known (we are talking about transplantation, not sewing their own limbs to the body – doctors have learned to do this for a long time).
But what about the head? Everything is much more complicated here. The fact is that doctors have never performed an operation to restore a completely divided (cut or separated due to injury) human spinal cord. We are talking about the need to connect millions of nerve endings, which is much more difficult than "sewing" a new heart (although this operation is very difficult). Organ transplantation requires the connection of a much smaller number of nerve endings or blood vessels than in the case of a head transplant. Only in 2017, doctors learned how to transplant hands from one person to another in such a way that they could function normally (not completely, but at least partially).
The same Canavero previously stated about the successful "gluing" of the spinal cord of mice. But even this has been questioned by a number of neurosurgeons. The scientists who carried out this operation did not provide a number of details in the description of their experiments.
And here we are talking about mice, about the restoration of a deliberately damaged spinal cord. As for humans and head transplants, everything is more complicated here. The fact is that our brain is a very delicate organ that is irrevocably damaged in the absence of oxygen supply /nutrition. A few minutes of disruption of the blood supply to the head and that's it – irreversible disorders of brain functions appear. Maybe it is possible to avoid a cardinal violation of the functioning of the brain if you cool your head during the transplant. But this is just a guess, no research has been conducted on this topic yet.
A heart cooled in a special way can last for quite a long time, and it can be transplanted. But the brain? It's unlikely. Many brain specialists believe that even if this organ is cooled and theoretically successfully transplanted, it will not be able to work normally.
Even if this happens, there is no guarantee that the happy owner of the new body will not have a desire to get rid of it. For example, once a patient who received a freshly sewn penis soon decided to get rid of it. The reason is purely psychological. Similar problems without such a radical solution were observed in patients who received a new face. But the arguments about psychology are here for the sake of a red word, since the success of transplanting even the head of a corpse is in great question.
In the annals of medicine there is information about the successful recovery of significant spinal cord injuries. But it talks about solving the problem of trauma in a small child whose nervous system is still being formed, and not in an adult. The operation to connect the spinal cord of the donor and the acceptor so far looks like pure fantasy.
What really happened?
In fact, a "successful" transplant is a transplant of a corpse's head onto the body of the same corpse. Yes, of course, operations on dead bodies are the most important aspect of surgical training. Before starting a heart transplant or other organs, specialists trained for many months. Here, indeed, we can say that "the path to success is paved with corpses." Moreover, there is no negative implication here.
But there is one problem. If the same heart transplant, which is much inferior in complexity to head transplant surgery, required training on dozens of dead bodies, then what can we say about the head transplant itself? Hundreds of training operations will probably be required here before real work can be started. But Canavero claims that the current operation is something like an introduction to an operation on a living person (more precisely, two conditionally living people). And at the moment she is the only one.
It cannot be called successful, since the operation can be considered as such only after it is performed with a living patient who remained alive and capable after the surgeon's work. "Perhaps this procedure showed the possibility of successfully connecting nerves and blood vessels, but the operation itself was not successful, because it requires a result in the form of a living and functioning organism," says Dean Burnett, a neurosurgeon.
"We are still far from the goal. You can connect two halves of cars into a single whole and call it a successful job, but after trying to start the car, the system will ignite or simply stop working."
Barnett says that Canavero has talked many times about successful operations that other surgeons do not consider as such.
"I don't understand why he's so sure. And no one seems to know. He didn't publish anything. His "successful" transplantation became known long before the publication of the results in the form of a scientific article," Burnett said. The scientist says that human body parts cannot be added or removed in the same way as it happens with Lego figures. There are a lot of problems when connecting the head and body, even if they belong to the same person.
The problem is that Canavero talks more than he writes. A real scientist should record his success with a long series of publications, where it is described in detail how the operation took place, what successful and unsuccessful moments can be distinguished. Instead, Canavero gives numerous interviews with statements of success. Of course, he needs the attention of society, but the problem is that scientists cannot be convinced by the usual "hype", something more serious than just statements is required.
What's next?
After publication in a number of media with statements about his "success", Canavero began to promise that an operation with a conditionally living patient would take place soon. We are talking about a person who is in a vegetative state. At the same time, Canavero claims that there are already "volunteers". While, however, it is unclear how people in a coma could inform the Italian about their consent to participate in medical experiments.
Now the talk about performing an operation with a patient who is conscious (without anesthesia) has somewhat subsided.
Valery Spiridonov, a Russian programmer, recently said that his participation in a head transplant operation is under a very big question. The preparation of the operation is actually frozen. The problem, according to Spiridonov, is that Kanavero receives funding from the Chinese government, which plans to conduct the first operation with a citizen of its own country. The Chinese, in particular, provided the surgeon with his own laboratory in a local clinic. Well, since Russia does not give the scientist any funds, Canavero agreed to the conditions of the Chinese.
"As for my own operation, I have a large number of personal plans, personal affairs. While Dr. Canavero is doing experiments, I am doing my health, my future. I'm not betting everything on him, I'm doing what I like. But I support him in every possible way and I believe that this technology should develop as a logical continuation of transplantology," he said Spiridonov RIA Novosti.
The fact that it was Spiridonov who became the first and main candidate for a head transplant became known in 2015.
Portal "Eternal youth" http://vechnayamolodost.ru