Throughout the last century, there were many significant advances in the medical field that could have been easily considered miracles in the past. With the development of antibiotics, advanced surgical procedures, and other medical treatments, life expectancy has increased exponentially. Though we are still far from gaining the knowledge and medical expertise to treat all diseases, we are on a path towards that goal as the first human head transplant is planned to take place in December this year.
In 2015, Dr. Sergio Canavero, an Italian neurosurgeon, has said that with improved technology and the ability to more accurately supply the neural tissue with fluids, it should be possible to successfully perform a head transplant by the end of 2017. In December he intends to perform the surgery.
According to Dr. Canavero, the surgery would take around 36 hours to perform and involve 150 members of medical support staff. After spending 30 years on research, he has devised a two-part procedure for the transplant. He calls the procedure “HEAVEN” (HEad Anastomosis VENture) and “GEMINI” (subsequent spinal cord transplant). The surgery would be performed on the recipient Valery Spiridonov, and a brain-dead donor who matches Spiridonov’s height, build, and immunotype. The donor will be screened beforehand to assure the absence of active systemic and brain disorders.
A 31-year-old Russian programmer Valery Spiridonov who suffers from Werdnig-Hoffmann disease, a highly debilitating and degenerative muscle atrophy disease, has volunteered to undergo the head transplant surgery. In December 2017, he will become the first ever human to do so.
The Werdnig-Hoffmann disease is a type 1 spinal muscle atrophy (SMA) and the most severe form of SMA. It is most commonly seen in newborn babies. It causes the death of motor neuron cells and progressive muscle wasting, eventually leading to death. The disease has left Spiridonov confined to a wheelchair and dependent on other people to help him every day in various tasks. He has stated in an interview that,
“Today my life is pretty tough, I need to rely on people to help me every day – even twice a day because I need someone to take me off my bed and put me in my wheelchair. It makes my life pretty dependent on other people. If there is a way to change this, I believe it should be tried and used.”
First, the muscles and the blood vessels in the neck are cut after freezing the head to avoid damage to brain cells. Then, the spinal cord is cut using a diamond nanoblade. Finally, the spinal cords will be fused, and the blood vessels and muscles are connected to those of donor’s body.
During the first phase of the surgery, two teams will work together to make deep cuts in the neck exposing the carotid and vertebral arteries, jugular vein, and the spine. A few more cuts will be made to give access to the trachea and esophagus. The muscles will be color-coded so that they could be attached correctly later. After that, the spinal cords of both the patient and the donor will be cut simultaneous using a $200,000 diamond nanoblade. All of this has to be done within an hour to minimize any brain damage.
The head is then immediately transferred to the donor’s body and the spinal cords are adjusted and fused within one or two minutes. In the next fifteen to thirty minutes, the blood vessels would be connected using chitosan-PEG (polyethylene glycol) glue to start circulation and theoretically warm up the head. The layer surrounding the spinal cord, the dura, will then be stitched, and the trachea, esophagus, vagi and phrenic nerves will also be connected. Finally, the muscles will be connected and the skin sewn by a plastic surgeon.
Once the surgery is done, the recipient will be kept in a coma for three to four weeks in order to avoid any ruptures of the sutures. Immunosuppressants will also be given to avoid rejection, just like for other transplant patients.
Transplanting a head has been attempted a few times in the past on dogs and monkeys. Recently, a team led by Dr. Xiaoping Ren of Harbin Medical University of China has conducted a head transplant on a monkey based on the research of Dr. Canavero. However, the surgery did not include connecting the spinal cord and only the blood vessels were connected. According to Dr. Canavero, the monkey fully survived and suffered no neurological damage. It regained consciousness within three to four hours and was kept alive only for twenty hours due to ethical reasons. Though many people have expressed skepticism about medical technology advancing enough to make the surgery a success in humans, Dr. Canavero and Spiridonov believe it is not impossible.