He is a distinguished
professor of neurosurgery at one of the most prestigious universities in
the United States and a Harvard Medical School graduate.
He has counseled
two Popes on bioethical issues and is the father of ten children. Now in
his mid-70s, Dr.Peter White is convinced that his life's work will result
in the first transplant of human head onto a brain-dead body sometime in
the near future.
According to
Dr. White, biomedical and surgical technology has finally caught up with
living brain transplant techniques he pioneered 40 years ago, and has since
perfected with trial-and-error clinical research on animals at Case Western
Reserve University in Cleveland, Ohio.
Head transplants
are not as far-fetched as they sound, nor is the research new. As early
as 1908, a scientist transplanted the head of one dog onto another dog's
body. In the 1950s, a Russian scientist created "two-headed dogs" by attaching
the front part of one dog onto another dog's body and connecting its arteries
so that the second dog's head continued to receive blood and remained alive.
One survived for almost a month.
In the 1970s,
Dr. White demonstrated for the first time that a primate brain could be
removed and kept alive if it was quickly attached to the circulatory system
of another monkey. Although attached to the living body of another rhesus
monkey the transplanted head, once the anesthesia wore off, was alert and
aggressive in its expressions. The eyes even tracked the nurses
and doctors as they moved around the operating theater. The monkey survived
for eight days.
"With the significant
improvements in surgical techniques and postoperative management since
then, it is now possible to consider adapting the head-transplant technique
to humans," Dr. White wrote in an article published in Scientific American
magazine in 1999.
Two years later,
on his return from addressing leading scientists in the United Kingdom
on cloning and other issues, he says brain transplants, not stem cells,
are the wave of the future for quadriplegics.United Press International
spoke with him at his laboratory by phone.
Q: Why transplant
heads or brains?
A: The recognition
that it is possible to transplant healthy heads or brains has gained momentum
in the past few years because of the need to help those who are paralyzed.
People like
Mr. [Christopher] Reeves, for example, have shortened lives -- anywhere
from five to 30 years off their lifespan, simply because their bodies start
to fail.
The central
question in recent years has become whether the procedure can be performed
on humans whose organs are failing. And the answer is yes, eventually.
Q: How is it
done?
A: With our
first operations in primates we solved the issue of whether the model we
had created of a pure brain transplant was even possible.
Could the brain
removed as a living organ from the skull, be sustained, that is kept alive,
and then be reattached to a second host animal? We discovered yes, it was
possible. First in dogs and then in monkeys. Not transplanted into the
skull itself, but onto the neck of the host.
Q: So the animals
had two brains?
A: These were
intact animals, so you could argue that they had two brains connected by
a single vascular system. These experiments were done to study the problem
of immune rejection and to examine the possibility of keeping the brain
alive outside of the body.
Q: What was
it like in the early days of brain transplants?
A: Our laboratories
back in the 1960s were the first to remove the brain of a living animal
and keep it alive using the circulatory system of another animal. Then
we designed and developed the equipment so that the brain could be kept
alive using just with machinery for reasonable periods of time.
Then finally
we went to the transplant mode to increase that period of time and provide
more normal circulation.
Q: Was the animal
conscious afterwards? Could the head hear, taste or smell?
A: Even though we
had superb EEG runs and the biochemistry looked pretty good, people asked
us the same question. With the help of NIH funding at the time, I developed
a scheme to remove one part of the brain and replace it with another.
That way we
could use the cranial nerves. In other words, could this technique allow
the brain to be conscious? I'm happy to report that the removal and replacement
of the brain in a rhesus monkey was a success. So the question of whether
the transplanted brain retained its conscious capability and performance
through cranial nerves was demonstrated.
Q: So that led
to the idea of testing the procedure on humans?
A: Even at that
time there were people saying if I can do the same in humans, maybe I could
help paralyzed people.
But I had no
capability to sew the spinal cord back together again, and still do not.
What you wind up with, I suppose in a tragic sense, is Mr. Reeves. You
have the A head which came from the A body and you have the B body who's head has been detached.
But they still cannot move.
Q: Where would
you get human donor bodies?
A: Well, that's
no problem. There's a Level 1 trauma center here and we get those individuals
who do themselves in various ways through injuries to the head, such as
motorcycle accidents. The body is intact but the brain is dead, so the
body would serve as a source for organs now.
In our case,
the whole body would be utilized to replace the diseased body of someone
who was quadriplegic.
Q: What about
the head?
A: The accident
victim will have to be pronounced brain dead, thus the justification for
removing the head and keeping the body. Instead of removing the organs,
the liver and kidneys, we would provide the entire body.
Q: And then
attach the head somehow?
A: Yes, at the
neck. The operative protocols are all worked out. This would primarily
be what we would call surgery at the cervical, or neck, level.Since the
spinal cord could not be attached to the head, when the tissues are all
closed and the spine would be fixed with special metal plates. This is
part and parcel with modern day spinal surgery-there's nothing new there.
Q: It's a big
step going from animal model to a human, isn't it?
A: I think
it would be easier to do this in humans than in rhesus monkeys because
in monkeys all the blood vessel, nerve and tissue work had to be done under
the operating microscope. In the human case, doctors like me operate almost
every day on the neck. There's an anatomical familiarity to the human neck
for surgeons.
Q: What's the
record for transplant survival?
A: Most animals
survived for several hours, perhaps a few days. I think the longest
was eight days. But please remember we were not funded to see how long
we could keep these monkeys alive, it was to see if we could develop and
design a protocol that might prove feasible in humans. As it was, we were
not set up to keep them alive.
We had to beg,
borrow or steal nurses and other doctors and, in essence, turn the entire
laboratory into an intensive care unit for a few days.
Q: How did they
die? Did the host body's immune system simply reject the head?
A: No. What
ran out were the lungs. The monkey lung is really quite small. There was
some immune rejection, such as swelling in the mouth and lips and the start
of tissue death, but the bodies gave out first.
Today, of course,
we have a number of immunosuppressive drugs to use and artificial respiration
is standard OR care. It shouldn't be a problem.
Q: So did you
succeed or fail?
A: The one thing
that came out of this, in addition to simply proving the feasibility of
whole brain and head transplants, was the fact that that the whole brain
could be preserved with its intact circulatory infrastructure apart from
the body long enough for it to be transplanted onto a second body. That's
a major advance.
Q: So when will
we see the first head/brain transplant in a human?
A: I have no
doubt that sometime before 2050 this operation will be undertaken, perhaps
sooner. A number of countries have offered me laboratories to begin the
initial experiments, but they don't have the money. In terms of equipment,
I've worked all that out -- I even have the equipment to support the brain
in transit without compromising its vascular sensitivity.
During surgical
transfer you just use deep hypothermia, deep freeze, or mechanical support.
It's not a problem.
Q: This issue
is should it be done?
A: We're talking
about a procedure that might help only a small number of people, mostly
quadriplegics whose bodies are failing.
Q: Obstacles?
A: It will be
expensive and such things as infection and
immunological rejection
will also be a problem. We got a lot of help with the success of hand transplants.
You can almost consider the wrist as simply a small neck. The same tissues
are there. That gives us reason to be hopeful.
Q: Would the
public accept this?
A: I think in
general the public seem to be accepting
xenotransplants. Once the
hysteria over what seems to be initially a strange scientific procedure
dies down, and people see the benefits, they gradually accept the science.
Q: You have
consulted with two Popes, including His Holiness John Paul. How do they
feel about your work?
A: I'm a member
of the Pontifical Academy of Sciences, which goes back about two centuries.
It has about 78 members appointed by the Pope. About one-third of them
are Nobel Laureates. About eight or nine are American and the majority
of them are Jewish. I'm one of the few Catholics. In discussions with the
current Pope, he seems to leave the issue of transplantation up to the
doctors.
Q: What about
the Christian concept of the soul?
A: I've discussed
the issue of brain death and the soul with the Holy Father and with other
theologians -- at what time does the soul leave the body? If brain death
is accepted as the end of life, then where is the seat of human soul? To
me, the answer is obvious. It's in the brain.
If we accept
and define human death as the destruction of a single organ, the brain,
a concept pretty well accepted by the Catholic Church and the medical community,
then when the head and the brain are alive, the soul is present.
Conversely,
if the body is alive and the brain is dead, the living brain being transplanted
would then carry the soul in its new body.
--
Copyright 2001 by United
Press International.
All rights reserved.
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