A few days ago, the news that "the world's first head-changing operation was successfully carried out on the remains" aroused great public concern. The scene of "head-changing" seen in science fiction works has now moved to reality.
What kind of "surgery" is "head change"? Is living surgery expected to succeed? Are you still you after changing your head? In response to the above-mentioned series of widely concerned issues, Zhongxin. com reporter. Com recently interviewed authoritative experts in the industry.
What exactly is "head replacement surgery"?
According to media reports, Italian neurologist sergio canavero recently announced that the world's first "human head transplant" has been successfully carried out on a corpse, and the location of the "operation" is China, and Ren Xiaoping, a professor at Harbin Medical University, participated in and directed the "operation".
According to reports, this "operation" lasted 18 hours and connected the severed spine, nerves, tissues and blood vessels. Ren Xiaoping named it "allogenic head reconstruction".
Previously, Canavero also revealed the detailed surgical steps: First, the new body will come from a donor with normal brain death. During the operation, the head of the donor and the head of the recipient should be cooled to the temperature required for the operation to slow down the metabolism of the human body.
Then, the doctor will dissect the tissue around the neck and connect the main blood vessels with tiny catheters. After that, the most important link is to cut the spinal cord neatly, exchange heads, and connect the brain and spinal nerves with the new body with special adhesives.
According to the design, the patient will be in a coma for one month after the head change, and it will take one year to recover.
Is living surgery expected to succeed?
Two years ago, Canavero announced that the first human head transplantation would be completed within two years. The man who underwent the operation was Valery Donoff, a Russian computer engineer who was born with spinal muscular dystrophy.
But Donoff changed his mind in the first half of this year, saying that he would not change his head now. This also means that he may not be the first person to undergo surgery.
Then, does the completion of this "operation" on human remains mean that future living surgery is also expected to succeed?
In this regard, Ren Xiaoping said in an interview with the media that this "operation" provided the whole operation principle, surgical approach, the choice of surgical anatomical structure, and the repair methods and techniques of various tissues for future experiments.
"The success rate of the living body will be known only after it is made, and the pre-clinical design scheme will be continuously improved." Ren Xiaoping said.
Hu Yongsheng, deputy director of the Department of Functional Neurosurgery at xuanwu hospital of Capital Medical University, previously stressed that "surgery should refer to surgery performed on a living body, and what is actually performed on the remains is anatomy or anatomical research."
He said that the current medical technology can completely realize the reconstruction and anastomosis of blood vessels, nerves, muscles and bones, but the most critical problem is how to perfectly realize nerve regeneration and functional reconstruction after spinal cord amputation. There is no breakthrough research progress in the world. "It is of little practical significance to talk about living skull transplantation now."
In an interview with Zhongxin. com. Liu Ruen, member of the Standing Committee of Neurosurgery Branch of Chinese Medical Association and chief physician of Neurosurgery Department of Peking University People's Hospital, stressed that the success of the operation depends on whether the human body can achieve coordinated, unified and effective life activities and effective survival under the control of the brain after the operation.
What difficulties need to be overcome to realize "head-changing"?
"'head change' is different from other organ transplants. It is not only to connect blood vessels after transplantation, but also to complete blood supply and nerve docking. The most important thing is the overall coordination after transplantation. " Liu Ruen explained to reporters.
He said that the coordination of all human functions depends on the brain, the normal operation of organs in the body depends on the control of the nerve center of the brain, and the balance of endocrine and water and electricity in the body depends on the control and adjustment of pituitary and adrenal axis. Implementing "head-changing" means that the central nervous system is completely isolated from the body, some organs will not be able to operate autonomously, and endocrine and hydropower balance will not be able to mediate independently.
According to Liu Ruen's analysis, assuming a "head-changing operation" is performed on a living body, the autonomous activities of the human body and the autonomous operation of internal organs after the operation need to wait for nerve regeneration and repair. Prior to this, external assistance can only be used to maintain the operation of organs and the balance of human water and electricity.
"However, if the organ loses neurotrophic for a long time, it will shrink and even die. It is also difficult to maintain the balance of water and electricity in the body for a long time through infusion adjustment. " Liu Ruen said.
In his view, there is no scientific research to prove how long organs can keep without atrophy without neurotrophic. In addition, although the nerve will regenerate, the time and degree of its regeneration can not be predicted at present.
In addition to these unknown problems, like other organ transplants, "head-changing" must be matched, and at the same time, it must face a series of problems such as the re-establishment of the systemic immune system.
After the head change, "you" or "you"
If the "head change" can really be realized, then another question that the public is concerned about is, who will this person eventually become if his head is replaced by another person's body?
In this regard, Liu Ruen explained that because people's activities are dominated by consciousness in the brain, after the "head change", the receiver keeps his own head, and the consciousness is still his own, and dominates others' bodies through his own consciousness, so he will inevitably face a series of ethical problems.
Hu Yongsheng's concern is how to solve the ethical problems that follow, even though head transplantation is completely feasible in science and technology in the future. Who are you after the head transplant?
He believes that at present, head transplantation needs to keep a clear head and avoid being impetuous and grandiose. Scientific exploration is meaningful and excessive publicity is useless.
How many social and ethical issues are involved behind the "head change"?
"Head-changing" has been controversial in the world medical field, and even attracted criticism from people in the industry.
Paolo Ma Erkai, a professor at Karolinska Medical College in Sweden, once said that he thought the Italian doctor Canavero was a "criminal". Because this kind of surgery has no scientific background.
Hunter Badger, president of the American Association of Neurosurgical Medicine, also said, "I don't want anyone to do this kind of surgery, and I won't allow anyone to do this kind of surgery on me, because there are many situations that will be worse than death."
Earlier, Ren Xiaoping also bluntly said that a head transplant is a whole body transplant, which inevitably involves ethical issues.
At the same time, some outside analysts also pointed out that this new research may bring social problems in addition to disputes in the medical field and ethics.
For example, how to legally define a person who has changed his head? If you break the law, who should bear the responsibility? How to define a new individual in law?
"'head-changing' is only an exploration at present, and there is still a long way to go to realize it in the future. Before general surgery is directly applied to clinic, it needs to be proved by a large number of live animal experiments. If' head-changing' is directly applied to clinic, a series of ethical problems will inevitably arise. " Liu Ruen said.
In this regard, Wang Yue, a professor at Peking University Institute of Medical Humanities, also stressed earlier that since medicine involves human life, it is actually risky and irresponsible to let patients do this experiment without sufficient evidence to prove its safety.