readings> head transplants
Fancy a bit of extreme surgery? Then what about a head transplant?
You've got a patient whose body is riddled with cancer or wasting away
with a degenerative disease. There's also a suitable donor down at the
local head trauma unit. So snip, snip; stitch, stitch - problem solved.
Old head, new body!
For several decades, Robert J White, a professor of neurosurgery at Case Western Reserve University, Cleveland, Ohio, has been the man most likely to give this history-making operation a go. He has openly talked about it as an option for the likes of quadriplegic Superman actor, Christopher Reeves, or amyotrophic lateral sclerosis sufferer, Stephen Hawking. And he has the skills.
White pioneered many surgical techniques including extracorporeal hypothermic perfusion where brains are chilled to 10 degrees Celsius to allow blood flow to be interrupted for up to an hour. But he became famous - notorious in vivisection circles - for his experiments in the 1970s in which he transplanted the heads of rhesus monkeys. It took a team of thirty doctors, nurses and technicians. Chalk marks on the floor were used to choreograph the procedure beforehand. After a monkey eventually survived the 18 hour operation, a cheer went up when it immediately bite the finger of the nearest assistant.
Of course, White's monkeys were left paralysed from the neck down. There was no chance of knitting together the sectioned spinal cords and so it was mostly a technical exercise in swapping over blood supplies and sewing muscles. Immuno-rejection and other complications also meant that none of the animals lasted more than nine days. But in the early 1990s, White began to prepare for a similar operation on a human. He went down to the mortuary to practice on cadavers. His procedure involved cutting through the neck at the fourth vertebra, dissecting out blood vessels and exposing the spinal cord. Metal plates would be used to mate the two halves. First the carotids and jugulars would be connected, then if all went well, the vertebral arteries. As a fall back, White had his brain cooling equipment to buy extra time during the switching of blood supplies. His main concern, he said, was not the operation itself but handling tissue-rejection afterwards.
White had a medical rationale for the procedure. He admitted the patient would end up a "head on a pillow", paralysed and with no longer even the breath control to speak. The donor body would have to be ventilated and drip-fed. Yet a terminally-ill cancer sufferer or a quadriplegic with multi-organ failure might take this extreme option - at least they would still be able to watch Oprah on the TV or listen to Mozart, White commented. He indicated the only thing really holding him back was the need to raise several million dollars to pay for the operation. White was not so concerned about the blessing of hospital authorities as he had colleagues in Kiev and elsewhere eager to take part in this ground-breaking neurosurgery.
Well, the years have come and gone and it hasn't happened yet. White is nearing 80 and long-retired. However, while it is unlikely he will now ever wield the knife himself, his associates could still spring a surprise on us one of these days.
It does make one wonder what the future has in store. Some think head transplants will become routine just as soon as can also manage spinal cord regeneration. Who could object if we knew how to join the two halves properly? But this seems a pipe dream. There is no reason to expect that the spinal tract of one body could ever form a functional connection with another. Even with intensive physiotherapy to retrain the brain's somatosensory organisation, a patient would likely remain just a spastic twitch or two better off than paralysed. Without a functional connection there is also the obvious problem of the survival of a decapitated body. Once cut-off from the brain-end of its autonomic, endocrine, immune, and who knows what other control systems, just how long could a torso survive?
Perhaps a transplant of a patient's entire CNS - brain and spinal cord - might work. But if society really has the stomach for this kind of surgical intervention, then why not go the whole hog and simply hook up a severed head to a bionic life support machine? Dump the donor body with all its own medical complications and just clamp a head to a rack of blood pumps, oxygenating and feeding equipment, a dialysis unit, and other necessary kit. These days you could disguise the machinery in a latex prosthetic body and stick the whole lot in a motorised wheel chair. Well, what's to stop the really ambitious neurosurgeon? Apart from the raising the cash?