Human head transplants are thought to be just around the corner. As was announced last week, neurosurgeon, Dr. Sergio Canavero, from the Turin Advanced Neuromodulation Group in Italy, maintains that surgeons may be able to transplant a human head onto an entirely different body by 2017. Canavero believes the revolutionary new surgery might save people with metastatic cancers and degenerative conditions. It might even be used as a treatment for gender dysphoria.
Head transplants have been performed before. Soviet surgeon Vladimir Demikhov performed the first documented attempt at a head transplant in 1954. He transplanted a puppy’s head and forelegs onto the back of a larger dog. The dogs managed to survive between two and six days with each attempt. Dr. Robert White carried out the first successful head transplant on a monkey in 1970. Although the monkey’s body was paralysed, it was able to breathe with assistance and remain alive for nine days before the immune system rejected the head. Since then however, surgical procedures and medicine have progressed significantly; immunosuppressive therapy is used to prevent transplant rejection. Promisingly, Xiao-Ping Ren at the Harbin Medical University in China recently proved that it is possible to perform a basic head transplant on a mouse.
The ‘Gemini spinal cord fusion protocol’ technique Canavero plans to pioneer was published recently in Surgical Neurology International. Essentially, the crux of the procedure involves cooling the recipient’s head and the body of the recently deceased donor in order to extend the amount of time cells may survive without oxygen. Following the initial severance of the neck, major blood vessels are connected using tiny tubes. The spinal cords are then neatly cut and the head moved onto the donor’s body. To join the spinal cords, Canavero intends to use polyethylene glycol, which helps fuse together the phospholipid membranes of cells. Canavero aims to accelerate this process by using electricity to stimulate local sprouting between neurons. Finally, blood vessels and muscles are stitched together with microsutures and the patient is induced into a coma for three to four weeks, allowing enough time for blood vessels and neurons to refuse. When the patient wakes up, intensive physiotherapy aims to rehabilitate the patient to use their new body to be able to eventually walk out of the hospital.
Xiao-Ping Ren aims to successfully replicate Canavero’s technique in both mice and monkeys some time in the next few months.
Unsurprisingly, many researchers are embracing Canavero’s proposal with scepticism, prompting potential improvements to his plan. Besides the practical hurdles, there are ethical concerns too that may ultimately determine which societies or countries might welcome the surgery. Canavero’s procedure might be further improved considering the number of studies that have indicated how signals from our body (such as a rumbling stomach) may affect a person’s willpower, emotions and language – the person walking out of the hospital might be very different to the person who came in. In addition, blood infusions from younger patients have been shown to provide a rejuvenating boost to the recipient.
The leader of the project, dubbed HEAVEN-GEMINI, seeks to announce the plans at the annual conference of the American Academy of Neurological and Orthapaedic Surgeons (AANOS) in June, to be held in the US. This move is a call to action for interested parties to collaborate and contribute to the work together on the surgical technique. The executive director of the US branch of the International College of Surgeons has said, “We’re creating a venue for him to launch the project. There will be a lot of top international surgeons at the conference and we shall see whether it is well received.” While some experts disagree with Canavero’s timeframe, Canavero remains philosophical saying, “This is why I first spoke about the idea two years ago, to get people talking about it.”
What additional benefits might a head transplant offer besides a healthier body?