Resurrection of head transplant surgery

Azhaar Ashraf

Kings College London, UK

Ethically gross as it may seem, the first successful head transplant surgery was performed by a Soviet scientist by the name of Vladimir Demikhov to form a two headed dog. The transplant surgeon successfully grafted the head and forelegs of a smaller dog, Shavka, onto a bigger dog, Brodyaga. The ground breaking news was that both physically bridged dogs survived the intricate procedure and were able to see and move around independently. However, both expired four days later. Being a devout surgeon, Demikhov tried the experiment more than 24 times and the longest survival for any two headed dog was a month. The death was caused due to immune rejection.

Controversy generating procedure

Briefly, an incision was made at the base of the Brodyaga's neck exposing the jugular vein (large veins in the neck), the aorta (artery supplying blood from the heart to the organs) and a segment of the spinal column. Subsequently, two holes were drilled through the bony part of one vertebra and plastic strings threaded through each of the holes. Barring the details, the head and neck of the small dog was joined to the neck of the large dog, allowing them both to share the same heart to sustain life (Fig 1).

Experimental dog with two heads (photograph courtesy of Olga V. Demikhova). Derived from (Konstantinov, 2009).
Fig 1. Experimental dog with two heads (photograph courtesy of Olga V. Demikhova). Derived from (Konstantinov, 2009).

Amidst the tensions of the cold war, the Soviet surgeon inspired an American surgeon called Robert White to conduct head transplants on monkeys in the 1970s. White placed the head of one monkey onto the body of another monkey. Since the scientists were not able to fuse the spinal cords, the recipient monkey could not move its new head though facial expressions could be observed. The monkey was kept on artificial breathing but died in nine days following the procedure clouded with complications.

At the cutting edge of the impossible

The horror of Frankenstein might spring into action in 2017 as facts are turning out to be stranger than fiction. Sergio Canavero of the Turin Advanced Neuromodulation Group in Italy intends to use head transplant surgery to extend the lives of people suffering from degeneration of muscles and nerves that renders them paralysed. To add to one's apprehension of the procedure, a terminally ill Russian computer scientist suffering from an inborn genetic muscle-wasting disorder called Werdnig-Hoffman disease is set to be the first volunteer/Guinea pig. If the procedure does get the green signal, the volunteer-to-be by the name of Valery Spiridonov would obtain his new body from a brain dead donor (Fig. 2).

Figure 2 - Werdnig-Hoffman muscle wasting disease sufferer Valery Spiridonov hopes to be the first person to undergo a head transplant so he can possess a fully functioning body.
Fig. 2 - Werdnig-Hoffman muscle wasting disease sufferer Valery Spiridonov hopes to be the first person to undergo a head transplant so he can possess a fully functioning body.

The hefty procedure would involve both donor and patient having their head severed from their spinal cord concurrently using an ultra-sharp blade to produce a clean cut. The head of the patient would subsequently be placed onto the donor's body and attached using polyethylene glycol, a glue-like chemical to fuse the two ends of the spinal cord together. Polyethylene glycol has previously been demonstrated to promote the growth of spinal cord nerves in animals (Papastefanaki et al, 2015) but whether it's effectiveness can be successfully translated to humans remains to be seen. Moreover, the muscles and the blood supply would be stitched up before the patient is directed into a coma for four weeks to allow the head and body to heal together. If all goes to plan, the patient upon waking should ideally be able to move, feel their face and speak with the same voice. With the advancement of potent immunosuppressive drugs in the recent years, it is predicted that immune rejection would be avoided. To further improve chances of success, the head and body would be cooled to give the surgeons more time and to extend the time the cells can survive without oxygen. The details of the proposed surgery and its technical aspects are briefly outlined in Fig. 3 (Canavero S1, 2015).

Figure 3 - Summary of the futuristic human head transplant surgery. The upper most aspect of the spinal cord i.e. cervical cords of the donor and the recipient will be severed either with a sharp specially fashioned diamond microtomic snare-blade or nanoknife made of a thin layer of silicon nitride with a nanometer sharp cutting edge. The axons/connections of the spinal cord would be reconnected and this process would be accelerated using electrical stimulation via application of a spinal cord stimulator straddling the fusion point. A sealant substance such as Polyethylene glycol would be used to glue the repairing spinal cord cells together. Figure derived from (Canavero S1, 2015).
Fig. 3 - Summary of the futuristic human head transplant surgery. The upper most aspect of the spinal cord i.e. cervical cords of the donor and the recipient will be severed either with a sharp specially fashioned diamond microtomic snare-blade or nanoknife made of a thin layer of silicon nitride with a nanometer sharp cutting edge. The axons/connections of the spinal cord would be reconnected and this process would be accelerated using electrical stimulation via application of a spinal cord stimulator straddling the fusion point. A sealant substance such as Polyethylene glycol would be used to glue the repairing spinal cord cells together. Figure derived from (Canavero S1, 2015).

Conclusion

Demikhov was the first ever surgeon to demonstrate the possibility of heart and lung transplants. This procedure has undoubtedly saved numerous lives and his work deserves respect. The Frankenstein approach he initiated on dogs in form of head transplant was revived in monkeys but potentially sees its resurrection in humans. However, the Italian surgeon Sergio Canavero would need to amass 11.1 million dollars and a team of 150 doctors/nurses to accomplish the proposed 36 hour ground breaking operation. Whether this mission impossible would be possible remains to be seen.


References

Canavero S1 (2015). The "Gemini" spinal cord fusion protocol: Reloaded. Surg Neurol Int 6: 18.

Konstantinov IE1 (2009). At the cutting edge of the impossible: a tribute to Vladimir P. Demikhov. Tex Heart Inst J 36(5): 453-458.

Papastefanaki F1, Jakovcevski I2, Poulia N1, Djogo N3, Schulz F4, Martinovic T5, Ciric D5, Loers G3, Vossmeyer T4, Weller H6, Schachner M7, Matsas R1 (2015). Intraspinal delivery of polyethylene glycol coated gold nanoparticles promotes functional recovery after spinal cord injury. Mol Ther [Epub ahead of print].