Head Transplant Surgeries - A Possible Cure for Paralysis

Introduction:

Head transplant surgery, otherwise called whole-body transplant or full-body transplant, is a surgical procedure in which an individual’s head is transplanted onto another person’s body. The main aim of this procedure is to offer a new body to individuals who have had severe disabilities, including paralysis, with the belief of restoring their mobility. However, it is still being experimented on and explored through experimental procedures on animals, including rodents and dogs. These experimental studies have created ethical concerns and significant obstacles in performing the same to humans.

What Is the Origin and Background of Head Transplantation?

In 1908, Charles Guthrie made an unsuccessful attempt at head transplantation from a dog’s head to another dog’s neck. Vladimir Demikhov, in the year 1950, developed various surgical techniques to aid in vital organ and limb transplantation. In the 1970s, the first successful cephalic exchange transplantation was performed by Robert White. This procedure involved the transplantation of the head of a rhesus monkey to another headless monkey, and the transplanted head restored sensations like motor function in the face, smell, hearing, and taste but survived only for eight days. For assessing brain function post-ischemia, experimental procedures were performed on rats by Hirbayshi et al. and Niu et al. recently. Ren et al. also contributed to the surgical technique of transplanting heads to mouse models. Cannavero et al. had proposed a model for head transplantation in humans also. In 2017 Ren et al. successfully attempted cephalosomatic anastomosis using a human cadaver.

What Are the Significant Hardships Faced During Head Transplant Surgeries?

1. Selecting Donor Body: A suitable method for collecting the donor body has not yet been developed. Nevertheless, face transplantation and collection of donor tissues can be made possible. This can be ruled out when there is confidence among the scientific community in the viability of the procedure.

2. Head and Body Interventions on the Recipient and Donor: These factors constitute a complex set of surgical skills and effective coordination among a diverse team of surgeons, including neurosurgeons, cardiothoracic surgeons, plastic surgeons, neck surgeons, vascular surgeons, and orthopedic surgeons. Adding to the above, careful planning of the surgical protocol is important. Postoperative function preservation, such as phonation, spontaneous respiration, etc., can be preserved only by preserving the functionality of phrenic nerves, recurrent laryngeal nerves, and cervical plexus. This is a challenging task and also time-consuming. Intricate surgical procedures such as spinal cord reattachment, multiple vascular anastomoses, spinal cord fixation, and esophagus anastomosis also contribute to the complexity of the procedure.

3. Ischemia Time: Various techniques can be employed to maintain blood flow both in the recipient and the donor. It is especially important during the hypothermic phase before vessel reattachment, and this is achieved through an extracorporeal circulation machine and alternative techniques such as auto-cerebral hypothermic perfusion. Lowering the temperature of the recipient’s head to a sufficiently low level is crucial in head transplantation, thereby allowing disconnection and reconnection to the donor body.

4. Spinal Fusion and Spinal Cord Reattachment: The most significant challenge in head transplant surgery is the reconnection of the spinal cord to the recipient’s body. The spinal cord is an important organ that plays a vital role in the transmission of signals between the brain and the body. Scientists have failed to reconnect the spinal cord and restore functionality in experimental procedures performed on animals. The surgeons will perform a clean cut on the spine using an ultra-sharp blade.

5. Postoperative Issues: Following the surgery, the patients should be closely monitored with ventilatory and circulatory support in the ICU (intensive care unit). Stabilization of the head and the spinal cord is crucial for successful fusion of the spinal cord. Early intervention for intensive rehabilitation of quadriplegia is recommended. Neurogenic shock is a significant concern resulting due to sympathetic nerve and vagus function alterations. Postoperative complications might vary from paralytic ileus to a neurogenic bladder.

What Are the Ethical Considerations for Head Transplantation?

1. Public and Scientific Criticism: It is necessary to look back in history when the first organ transplant was done, and the public reaction was bizarre as it was considered to go against nature. In the history of medicine, many innovative ideas and procedures were initially rejected. Likewise, the EANS Ethico-Legal Committee labels this procedure as unethical.

2. Lack of Data: Since there is a lack of data and research still persists on this procedure, the scientific debate on this topic is almost hushed. Only a few research papers exist, and those, too, are just mere opinions or suggestions regarding the procedure.

3. Immunosuppression and Ethics: In theory, head transplantation can be a life-saving procedure with intact brain function and with terminal conditions. The risks associated with immunosuppression can be outweighed by the potential benefits that surgery has to do to an individual with significant disabilities. Another aspect of importance is the possibility of somatic rejection, which may, in turn, require higher levels of immunosuppression, and this can lead to harmful effects on the individual again.

4. Psychosocial Consideration: In the case of successful transplantation, the patient may require long-term rehabilitation and physical therapy. There are still doubts about whether the individual will lead a better quality of life post-head transplantation. Post-transplant, there can be an identity confusion between body and identity, thereby creating additional mental health assistance. There can be self-esteem problems due to asymmetries and scars. Other secondary issues include gender identification when there is a head transplantation done to different genders.

Conclusion:

The potential for severe complications, the intricate nature of the procedure, and ethical considerations have hampered the progress of this type of surgery. Meanwhile, it is worth noting that research is underway to restore ability in patients with paralysis through spinal cord stimulation, stem cell therapies, and neural prosthetics. It is essential for the scientific community to shift their opinion on this procedure from mere imagination to a significant scientific procedure that needs more analysis and studies. Specialized surgeons from various countries should voice their opinions and shed light on the pros and cons of their procedure and the feasibility of this procedure.