Head to body Transplant - Not Totally SciFi

There have been many different types of organ transplants that have improved peoples quality of life in recent years, but what if the head was the transplant, the control center of all individuals? I know what you’re thinking, “A human head transplant. Is that even possible”? According to surgeons Sergio Canavero and Xiaoping Ren it is, and it’s not just science fiction. Through HEAVEN/GEMINI, a spinal cord fusion procedure, transplantation may be possible (1,2). The first step of this project is to cool down/freeze the donor's (brain dead) spinal cord and the recipient's (physically disabled) head to around 12℃ by a process called autocerebral hypothermic perfusion where the recipient's head receives a cooling circuit through a pressure house to the carotid artery (2). Once cooled, both donor and recipient spinal cords are finely transected along regenerative axons while veins and arteries are cut (2). Once the recipient's head is fully severed, it is transferred to the donor body where spinal cord, veins, and arteries are connected microscopically with clamps, screws, wires and cables to support the new model (2). Plastic surgery to reconnect the skin is the last step (2).

The question now is will this really work? This question is not yet clear. Total spinal cord transection and reconstruction was successful in both rats and a dog, although these test subjects were not placed onto a new body (3,4). Respiration and behavior were merely the same post-operation as before in these subjects, however some subjects became paraplegic (3,4). The same was true for White et al. in which a laboratory monkey was the subject (5).

I suppose the biggest question here isn’t whether the procedure works or not, but whether the procedure is ethical from a biomedical standpoint. My immediate answer to this question was, “of course it’s not ethical, it’s crazy!” As I read more about this subject, I can now see the other side more clearly. A procedure like this could potentially better the lives of millions of people living with incurable muscular dystrophy, para/quadriplegics, and people who have any other form of incurable physical degenerative disease. Wanting to improve these people’s lives directly follows the biomedical ethical values. At the same time, if the procedure is unsuccessful all the ethical values can be broken. This debate only postpones the first attempt as we keep asking ourselves, “Where do we draw the line with transplantation?”  

References:
(1) Xiaoping, R., Canavero, S. (2017) HEAVEN in the Making: Between the Rock (the Academe) and a Hard Case (a Head Transplant). AJOB Neuroscience, volume 8:4, pages 200-205. DOI:10.1080/21507740.2017.1392372

(2) Canavero S. (2013). HEAVEN: The head anastomosis venture Project outline for the first human head transplantation with spinal linkage (GEMINI). Surgical Neurology International. DOI:10.4103/2152-7806.113444
(3) Kim, C.Y. (2016). PEG-assisted reconstruction of the cervical spinal cord in rats: effects on motor conduction at 1h. Spinal Cord, volume 54, pages 910-912. DOI:10.1038/sc.2016.72
(4) Kim, C.Y., Hwang, I.K., Kim, H., Jang, S.W., Kim, H.S., Lee, W.Y. (2016). Accelerated recovery of sensorimotor function in a dog submitted to quasi-total transection of the cervical spinal cord and treated with PEG. Surgical Neurology International, volume 24, pages 637-640. DOI:10.4103/2152-7806.190476
(5) White RJ, Wolin LR, Massopust LC Jr. Taslitz N, Verdura J. (1971).Cephalic exchange transplantation in the monkey. Surgery, volume 70, pages 135–139.