On November 21, Ren Xiaoping, an advocate of "head replacement" and a professor at Harbin Medical University, said at a meeting that the team had made a major breakthrough in the field of science and "completed the first experimental model of head transplant surgery in humans.".
At the brief meeting, Ren Xiaoping did not elaborate on the specific details of the transplant, but repeatedly emphasized the importance of the transplant, or self-proclaimed, or quoted the high praise of the editors-in-chief of many world-class surgical journals, such as "very remarkable", "landmark", "Apollo moon landing in the field of medicine"...
Ren Xiaoping said that the data, process and results related to the head transplant experimental model were published in the American academic journal SNI (Surgical Neurology International).
Ren Xiaoping
SNI is an academic journal published only on the Internet, and people have free access to the papers on them. As it is not currently included in the SCIENCE CITATION Index (SCI), there are no impact factor data. The Paper (www.thepaper.cn) retrieved the paper from SNI and found a paper by Ren Xiaoping's team published on November 17.
According to the paper, the researchers made three major advances: optimizing surgical procedures, preserving major nerves (diaphragm and recurrent laryngeal nerves), and assessing vertebral stability.
The conclusion was confirmed that it was feasible to perform head-swapping surgery together, and the next step was to plan a complete transplant procedure using the body of a donor with a beating heart but brain-dead organ and the head of a patient with a specific disease.
Regarding Ren Xiaoping's "Human First Head Transplant Surgery Experimental Model" and the results of the above paper, The Paper invited a number of industry experts to comment.
Affirmers of its significance believe that the process of head transplantation on the body shown in the paper provides anatomical information and the necessary surgical procedures.
But most people believe that Ren Xiaoping's head transplant on the body does not solve the most fundamental and basic problem to be overcome by "head replacement": how to overcome immune rejection? How does the central nervous system repair and regenerate? Therefore, "it is too early to talk about success." ”
Perhaps because of this, compared with the high-profile claim of the Italian Sergio Canavero, the author of the paper who is also obsessed with "head replacement", Ren Xiaoping is very cautious in wording: not "head replacement", but "experimental model of head transplant surgery"; do not use "success", it is "complete".
Ren Xiaoping's team paper published at SNI
Conclusion of the paper: Head transplantation of the body confirms that it is feasible to perform head replacement surgery
The 8-page paper was submitted to SNI on November 8 and was officially published nine days later.
Ren Xiaoping is the corresponding author, and his "head-changing" accomplice, the Italian Sergio Canavero, is the last of the 8 authors.
In the paper, the transplant was named "Human Head Transplant Anastomosis" (CSA).
The paper claims that in 1970, due to the lack of corresponding means to allow the neural electrical spark to cross the transverse spinal cord (in other words, to repair the broken spinal nerve), the relevant experiments were not further carried out.
But now, researchers have discovered a new approach, and even if a piece of spinal cord is completely severed, it is possible to regain functional connections. With this remarkable advance in mind, we (referring to Ren Xiaoping's team) accepted the challenge of performing the first head transplant anastomosis on a human body.
The paper shows that the transplant was carried out at Harbin Medical University and was carried out on the remains of two recently deceased men of similar shape.
Unlike transplants involving individual organs (heart, liver, kidney, lung, pancreas, etc.), human head transplant anastomosis requires the work of neurology, vascular, orthopedic, gastrointestinal, and cardiothoracic surgeons.
Two surgical teams, a total of 5 doctors, operated on the two bodies in an all-time process that took about 18 hours, and all the operations were completed within the expected time.
The researchers made the following advances: optimizing surgical procedures, preserving major nerves (diaphragm and recurrent laryngeal nerves), and assessing vertebral stability, the paper writes.
The paper suggests that it is best to perform a transgression at the "watershed" between C4 and C5 of the spine, because this is a matter of whether it can speak normally, and the key nerve that produces speech, RLN, needs to be focused on. The vagus nerve needs to be anastomose twice.
In addition, the paper reminds that because the distal nerve fibers in the spinal cord begin to die after about 20 minutes of severance, any delay in the transverse spinal cord is harmful and must be fused immediately.
The paper emphasizes that the above experimental operation was approved by the Human Research Ethics Committee of Harbin Medical University, and the family members who donated the remains also signed a consent form. The paper concluded that this transplant on the remains confirmed that it was feasible to perform a head replacement procedure together, and that there were no convincing obstacles to abandoning such a surgical procedure. In the next phase, the researchers plan to perform a complete transplant procedure using the body of the heart-beating but brain-dead organ donor and the head of a patient with a specific disease.
Based on this experimental procedure, the researchers speculated that in actual "head changes," hemostasis-related procedures may increase the duration of surgery. Coupled with anesthesia and hypothermia induction, the entire head transplant anastomosis may be completed within 36 hours. The minimum number of people required to safely complete the procedure is 16 people:
Divided into four separate teams of surgeons, each group includes at least 4 surgeons such as spine surgeons (plastic or neurosurgery) and vascular surgeons, cardiothoracic surgery, reconstructive surgeons, and general surgeons with experience or expertise in neck surgery.
Just finished the "rehearsal" in terms of anatomy and operation
Experts who have a positive opinion on the head transplant of the remains have focused on the anatomy and surgical procedures.
Professor Zhang Jinming, professor, doctoral supervisor and director of plastic surgery at Sun Yat-sen Memorial Hospital of Sun Yat-sen University, believes that the head replacement on the body provides anatomical data, which provides a surgical operation process for the "head replacement" that will be carried out in case of a certain day in the future, so it has certain value, but it cannot be speculated as "the success of the head replacement".
Regarding the paper's mention that "at deep hypothermia, the brain can survive for up to 1 hour without blood supply, which is enough for surgeons to complete all vascular anastomosiss," Zhang jinming said, at deep hypothermia, it is difficult for doctors to perform surgical operations.
An attending physician of neurosurgery, who did not want to be named, also told the surging news that the content of the paper published by Ren Xiaoping was necessary from the process of surgical operation.
The physician said that for the surgeon, if an operation he has never done, then he must simulate the operation on the specimen (human body specimen), such as blood vessels, nerves and other operations of a whole set of processes, in order to be carried out on the human living body, "this operation can be said to be a 'rehearsal' for future living head transplantation." ”
But the "rehearsal" is only completed in terms of anatomy and operation, and does not solve the problem of functional repair, and it is still far from the success of the so-called "head replacement". That is to say, the blood vessels and nerves of the two people are connected, and it is not necessary that the two can be matched to achieve functional anastomosis. "For example, connecting two cables does not mean that pulling down the electric gate will necessarily energize."
The neurology clinician believes that only from the process point of view, Ren Xiaoping's team's rehearsal of the (transplant) process time, etc., is very standard: where the nerve is cut from, where it is joined, (how) it is more conducive to operation, more conducive to survival...
"Overall, I'm neutral on this matter, I should try it rather than deny it completely, and there are at least some problems that we can try to solve, even if some of them can't be solved at the moment."
For example, he said, under the current technical conditions, there are spinal cord can not be connected, transplantation and other problems, with the development of technology if the future to solve, "then we have other technologies are already available, then all at once successful." ”
The interviewed physician commented, "At present, there is no problem in the process and operation, and it is also a step forward in what the predecessors did not do, but as for functional recovery, the next technical field - the field of nerve regeneration needs to continue research." ”
But for Ren Xiaoping's next step in the human living head transplant, the doctor said it was "not optimistic."
For Ren Xiaoping's "special chemical drug" used in spinal cord fusion mentioned by the media, polyethylene glycol (PEG), the interviewed doctor said that because the nerves could not be sutured, using PEG to bond the nerves was similar to using 502 glue to glue two pieces of tofu together.
Ren Xiaoping's exploration has not solved the most fundamental and fundamental problems
For Ren Xiaoping's body head transplant, the industry is more critical and opposed.
Dai Jianwu, an expert and researcher in regenerative medicine at the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences and secretary general of the China Stem Cell Branch, said that Ren Xiaoping's team's paper was not related to spinal cord injury repair, a key issue in head replacement surgery.
Dai Jianwu believes that "head replacement" is meaningless on the body, the core problem of head replacement is the problem of spinal cord injury repair, and PEG repair of spinal cord injury has no scientific basis.
In January 2015, the research team led by Dai Jianwu took the lead in carrying out clinical research on the treatment of old-fashioned complete spinal cord injury in the world.
Dai Jianwu reiterated that even if the "head changing" is feasible, it should also follow such a scientific procedure: it should be carried out first on small animals such as rats to prove that it is not dead and its motor function is restored, and then on large animals such as dogs or monkeys to prove that it can survive and motor function is restored, and then human trials are considered.
Wu Zhen, deputy chief physician of the Department of Neurosurgery at Beijing Tiantan Hospital affiliated to Capital Medical University, said that the study was suspected of speculation, saying that if PEG can repair the spinal cord, then many patients with spinal cord shock can repair it. "He is broken himself, can you just connect him directly, you don't have to do a head transplant."
Wu Zhen said that "head-body transplantation" faces three major problems, ethics, immune rejection and central nervous system damage repair. At this stage, the research progress of immune rejection and central nervous system injury repair cannot guarantee the success of "head-body transplantation". The research done by Professor Ren Xiaoping is only an exploration of the surgical process of human "head-body transplantation", and does not solve the most fundamental and basic problem: how to overcome immune rejection? How does the central nervous system repair and regenerate?
Chen Jingyu, a lung transplant expert and vice president of Wuxi People's Hospital, said, "(The paper) just said that it fits, but the actual function cannot be completely confirmed, which can be regarded as a practice on the body, but the effect is unknown." ”
He stressed that Ren Xiaoping's team's experiment on the remains did not explain too many problems, because it was not a living body.
For the high attention caused by this incident, Chen Jingyu has some concerns: the current media reports have made many people think that China has become the first country in the world to complete the "head changing technique", which will make foreign academic circles laugh, but it will have a negative impact on China's medical community.
【Companions say】
Zhang Xiaohua, Director of The Department of Neurosurgery, Shanghai Renji Hospital:
1, Ren Xiaohua's paper contains some blood vessels and nerves how to do reconstruction, some talk is quite deep, there are some technical things worth learning, but avoids the function of the spinal cord in the end how to rebuild, is currently only an anatomical research;
2. The main breakthrough of the paper: the use of technology to allow the spinal cord to retain function in a short period of time, so as not to cause damage to spinal cord neurons in the short term;
3. At present, how the spinal cord establishes a connection with the body, which is the most important channel of neural networks, and this study has not yet covered this part;
4, this is only an experimental study, although it can be morphologically established neural networks, but this network is not really able to produce function, this still has a long, long way to go;
5. Laboratory research may not be successful in the end, for example, even if some animal experiments are successfully completed, they must go through three phases of clinical trials (considered successful);
6. It is meaningless to spend energy on head transplantation, but if the anatomical findings in the research process can provide some highlights for the clinic, I think this is still desirable;
7, like Hawking, he has a very intelligent brain, but his limbs can not move, if you can rebuild his spinal cord first, this I think is a major discovery, rather than spending energy on head transplantation, because the most basic starting point of scientific research is for the benefit of mankind;
8, so far, including Canada, the United States has a special spinal cord reconstruction of people, but several major laboratories have not given a good solution, so not optimistic;
9. If the spinal cord can be completely reconstructed is 100 points, the current industry can only achieve a maximum of about 10-20 points, and Ren Xiaoping's research can not be scored, because it is believed that Ren Xiaoping's research focus is not spinal cord reconstruction, but only from the surgical completion of the relevant steps.