In 2013, Dr. Sergio Canavero published a paper outlining a potential method for performing a head transplant in humans. A later study by Dr. Xiaoping Ren involved head transplantation in mice. Dr. Robert White performed head transplants on monkeys in the 1970s, but the animals didn’t survive very long. The next step is to test head transplants in nonhuman primates using modern surgical techniques, though Dr. Canavero disagrees and is morally opposed to experiments on lab animals. Dr. Canavero and his plans for a human head transplant serve as the basis for a new in-depth Guardian article. Dr. Canavero and a team in China plans to perform a human head transplant (which may really be more of a body transplant) as soon as 2017. Dr. Michael Sarr, editor of the journal Surgery, thinks a human head transplant is plausible.
Head transplant volunteer Valery Spiridonov suffers from a form of spinal muscular atrophy. The transplant team plans for him to be the second or third patient after testing the procedure on other patients with reduced life expectancy, like those with terminal cancer. I wonder if the patient and his doctors have tried alternate treatments for SMA, including those that have only been tested in lab animals. Maybe gene therapies or cell therapies from the studies referenced at the end of this post could bring relief in less invasive ways than a head transplant. I’ve seen videos where paralyzed lab animals that could only drag their hindlimbs before can now run on treadmills. However, this was from research on treating spinal cord injuries rather than curing spinal muscular atrophy.
The question is whether treatments from lab animal studies transfer to adult human patients. Most experimental treatments for spinal muscular atrophy involve administering the treatment to neonatal mice instead of adult animals. If no alternative therapies (gene therapy, cell transplantation, nerve regeneration) end up working for this particular patient, people should respect the patient’s desire for a head transplant. They should accede to Mr. Spiridonov’s wishes instead of letting the obsolete philosophical beliefs of bioethicists and religious figures control his life.
These are the steps outlined in Dr. Canavero’s initial paper on head transplantation:
1. Match donor for height and build.
2. Screen donor immunotype.
3. Set up autotransfusion protocol using donor’s blood.
4. Intubate receiver and donor and ventilate through tracheotomy.
5. Lock heads in rigid pin fixation.
6. Place leads for ECG, EEG, oxygen saturation measurement, and external defibrillation.
7. Position temperature probes.
8. Insert radial artery cannula.
9. Administer antibiotics throughout procedure.
10. Administer barbiturate or propofol to receiver.
11. Keep constant cooling infusion.
12. Start lidocaine infusion.
13. Cool receiver’s head to 10 degrees C.
14. Use spinal hypothermia in donor.
15. Place receiver supine during induction of hypothermia.
16. Place receiver in the sitting position while keeping donor upright.
17. Make incisions around the necks of donor and receiver.
18. Separate the structures at C5/6 level forward below the cricoid.
19. Perform two cuts along the anterior margin of the sternocleidomastoids.
20. Perform one standard midline cervical incision.
21. Cut spinal cords simultaneously in both subjects while allowing for some slack.
22. Create a strain-free fusion to avoid the natural retraction of both segments.
23. Transfer receiver head onto donor body.
24. Connect the receiver head onto the donor circulation tubes.
25. Accost, adjust, and fuse the cord stumps.
26. Infuse chitosan-PEG into donor bloodstream.
27. Apply loose sutures around joined cord to thread the arachnoid.
28. Perform laminectomies in receiver and donor.
29. Perform a durotomy on receiver and donor to expose the cords.
30. Use bicarotid-carotid and bijugular-jugular silastic loop cannulae to accomplish vascular anastomosis for the cephalosomatic preparation.
31. Remove vessel tubes one by one.
32. Sew the arteries and veins of the transplanted head together with those of the new body.
33. Tip-clamp main vessels during head transference to avoid air embolism.
34. Verify donor blood flow begins to rewarm receiver head.
35. Reconstruct vertebral arteries.
36. Sew the dura in a watertight manner.
37. Perform anterior followed by posterior stabilization.
38. Connect the trachea, esophagus, vagi, and phrenic nerves.
39. Join muscles together by using color-coded markers.
40. Sew up skin.
41. Bring receiver to the intensive care unit and keep sedated for three days.
A large animal model of spinal muscular atrophy and correction of phenotype.
A Novel Morpholino Oligomer Targeting ISS-N1 Improves Rescue of Severe Spinal Muscular Atrophy Transgenic Mice.
A Short Antisense Oligonucleotide Ameliorates Symptoms of Severe Mouse Models of Spinal Muscular Atrophy.
A single administration of morpholino antisense oligomer rescues spinal muscular atrophy in mouse.
Allogeneic head and body reconstruction: mouse model.
Antisense Oligonucleotides Delivered to the Mouse CNS Ameliorate Symptoms of Severe Spinal Muscular Atrophy.
Bifunctional RNAs Targeting the Intronic Splicing Silencer N1 Increase SMN Levels and Reduce Disease Severity in an Animal Model of Spinal Muscular Atrophy.
Brain Transplantation: Prolonged Survival of Brain after Carotid-Jugular Interposition.
Celecoxib increases SMN and survival in a severe spinal muscular atrophy mouse model via p38 pathway activation.
Decreasing Disease Severity in Symptomatic, Smn−/−;SMN2+/+, Spinal Muscular Atrophy Mice Following scAAV9-SMN Delivery.
Direct central nervous system delivery provides enhanced protection following vector mediated gene replacement in a severe model of Spinal Muscular Atrophy.
Effect of Combined Systemic and Local Morpholino Treatment on the Spinal Muscular Atrophy Δ7 Mouse Model Phenotype.
Gene therapy rescues disease phenotype in a spinal muscular atrophy with respiratory distress type 1 (SMARD1) mouse model.
Genetic Correction of Human Induced Pluripotent Stem Cells from Patients with Spinal Muscular Atrophy.
Head Transplantation in Mouse Model.
HEAVEN: The head anastomosis venture Project outline for the first human head transplantation with spinal linkage (GEMINI).
Hypothermic preservation and transplantation of brain.
Improved Antisense Oligonucleotide Design to Suppress Aberrant SMN2 Gene Transcript Processing: Towards a Treatment for Spinal Muscular Atrophy.
Increasing expression and decreasing degradation of SMN ameliorate the spinal muscular atrophy phenotype in mice.
Increasing SMN levels using the histone deacetylase inhibitor SAHA ameliorates defects in skeletal muscle microvasculature in a mouse model of severe spinal muscular atrophy.
Peripheral Androgen Receptor Gene Suppression Rescues Disease in Mouse Models of Spinal and Bulbar Muscular Atrophy.
Peripheral SMN restoration is essential for long-term rescue of a severe spinal muscular atrophy mouse model.
Postsymptomatic restoration of SMN rescues the disease phenotype in a mouse model of severe spinal muscular atrophy.
PTEN Depletion Decreases Disease Severity and Modestly Prolongs Survival in a Mouse Model of Spinal Muscular Atrophy.
SMN2 splicing modifiers improve motor function and longevity in mice with spinal muscular atrophy.
Sodium vanadate combined with l-ascorbic acid delays disease progression, enhances motor performance, and ameliorates muscle atrophy and weakness in mice with spinal muscular atrophy.
The “Gemini” spinal cord fusion protocol: Reloaded.
Translational Fidelity of Intrathecal Delivery of Self-Complementary AAV9–Survival Motor Neuron 1 for Spinal Muscular Atrophy.