Brains, eyes, testes: off-limits for transplants?
PARIS, April 28 (AFP) - Since the world's first successful organ transplant in 1954 -- a kidney -- the discipline has advanced to the point where a wounded soldier could have his penis and scrotum replaced in a groundbreaking operation last month.
A Frenchman recently became the first person to receive a second face transplant after the first failed, and another made his- tory by regrowing skin lost over 95 percent of his body, thanks to a graft from his twin brother.
Transplants are no longer limited to the vital organs: heart, liver, or lungs. Nowadays, people can get a new hand... or even a uterus. But some organs remain off-limits. For now. Topping the list, brain transplants are a long way off, for both technical and ethical reasons, experts say.
“The most challenging organ to transplant is anything related to the nervous system, as we do not have effective techniques for nerve growth/ regeneration,” explained transplant surgeon David Nasralla, of the University of Oxford. “For this reason, eye and brain transplants are currently beyond the scope of modern medicine.” Nerves carry messages through the body in the form of electrochemical pulses flitting between the brain and spinal cord, muscles and other organs.
An Italian-Chinese surgical duo recently set the science world aflutter by announcing they planned to remove a person's head and attach it to a decapitated donor body in what would be the first such procedure. There is a high likelihood, observers say, that the patient will die. Many doubt it is possible to connect the nerve fibres of two spinal cords. Above all else, the undertaking raises troubling moral questions, including a very basic one: What constitutes a person? A brain alone? The patient, suggested a recent article in the journal Surgical Neurology International, will likely struggle with the concept of “human identity”.
Given the dire shortage of donor organs, the use of animal hearts, lungs or livers to save human lives has long been a holy grail of medical science. But organ rejection has stood stubbornly in the way of inter- species “xenotransplants”. “It was tried in the 50s and 60s, with kidneys from chimpanzees, for example. But organ failure set in immediately. They could not break through the species barrier,” said Olivier Bastien, of France's biomedicine agency. This is changing as scientists learn to modify the genes that prompt the immune system to attack intruder germs, but also foreign tissue perceived as a threat.
Few organs remain technically non-transplantable. But two are excluded, for now, due to their raising of ethical eyebrows -- the testes and ovaries. “A testicle transplant would amount to assisted reproduction in disguise,” said Bastien. One question is this: If the recipient fathers children with his new sperm-producing testicles, whose offspring are they -- his, or the donor's?