Head transplant possible soon, Italian surgeon says
An Italian neurosurgeon says it is possible to transplant human heads from one body to another to extend the lives of people whose muscles and nerves have deteriorated or whose organs are riddled with cancer.
Sergio Canavero said several people already have volunteered for a head transplant — which he says he could perform in 2017 — after he tests the procedure with brain-dead organ donors.
Canavero, a member of the Turin Advanced Neuromodulation Group, detailed the surgery in the journal Surgical Neurology International this month.
“The greatest technical hurdle to (a head transplant) is of course the reconnection of the donor’s and recipient’s spinal cords,” he said in the paper. “It is my contention that the technology only now exists for such linkage.”
He said a sharp severing of the spinal cord and the use of modern adhesives and sealants are the keys to success.
He discovered the importance of a clean cut as he reviewed cases of sharp wounds in the cords of patients who spontaneously recovered from paralysis.
In particular, Canavero cited a case in 1902 of a 26-year-old woman known as CN, whose spinal cord was severed by a .32 calibre bullet. The five physicians who examined the wound discovered a gap of three-quarters of an inch in CN’s spine.
With some difficulty, surgeons pulled the cord ends together with catgut sutures and 16 months later reported a partial return of function:
“The patient slides out of bed into her chair by her own efforts and is able to stand with either hand on the back of a chair, thus supporting much of the weight of the body.”
Canavero said the sharp severing of the cervical cord in both the donor and recipient is the first of four steps to a successful head transplant. The others, he says, are:
• Preserving two millimetres of remaining cord to help re-bridge the two stumps.
• Accelerating the rebridging with electrical stimulation across the fusion point.
• Flushing the stump ends with modern sealants such as polyethylene glycol to accomplish what doctors attempted in 1902 with catgut. The substances would seal injured and leaky neurons and simultaneously fuse severed axons with little scarring.
“Just like hot water makes dry spaghetti stick together, polyethylene glycol encourages the fat in cell membranes to mesh,” New Scientist said in a description of the surgery.
A head-transplant recipient would be kept in an induced coma for three to four weeks “to give time to the stumps to re-fuse (and avoid movements of the neck),” Canavero said in the paper. The recipient would begin a regime of immunosuppression so the head does not reject the body.
The procedure begins with cooling the patient’s head and the donor body to minimize cell damage without oxygen. Surgeons next dissect the tissue around the recipient’s neck to expose the severing point and link major blood vessels on either side with tiny tubes.
Surgeons must remove the heads of both patients, located in the same operating theatre, at the same time; They have no more than one hour to re-connect the preserved head to the circulatory system of the donor body, in which total cardiac arrest must be induced.
Once the head is reconnected, surgeons restart the heart of the donor body and reconnect other vital systems, including the spinal cord, says the website Quartz of the procedure. A recipient would have the ability to feel and move their face, speak with the same voice and walk within a year with physiotherapy, Canavero said.
Canavero intends to announce the project in June at the annual conference of the American Academy of Neurological and Orthopaedic Surgeons in Annapolis, Maryland.
He would like to carry out the experiment in the United States but it is unclear if he would receive approval.
Among the skeptics is Dr. Harry Goldsmith, who has performed one of the few surgeries that enabled someone with a spinal cord injury to regain the ability to walk.
“I don’t believe it will ever work, there are too many problems with the procedure,” he told New Scientist. “Trying to keep someone healthy in a coma for four weeks – it’s not going to happen.”