Sham surgery may put patients at risk
Researchers in the United States
have sparked off debate by using
a controversial form of placebo
surgery during clinical trials for
patients suffering from Parkinson's disease.
Investigators at the University of South Florida are using
"sham surgery" to test the efficacy of implanting fetal brain cells
into patients with severe Parkinson's disease. They hope that
direct injection of embryonic
dopaminergic neurones into the
brain will help patients regain
motor function in their limbs.
Researchers at the university
want to show that any benefits
are a result of the treatment and
not a placebo effect. To show
this, they have carried out placebo operations on a control
group of randomised patients, to
compare them with subjects
receiving the fetal brain cells.
The subjects in the control
group have holes drilled into
the side of their head, but,
unlike in subjects in the treatment group, the needle does not
penetrate their brain. Both
groups are put on a six month
course of immunosuppressive
treatment.
In an article in the New England Journal of Medicine, Dr
Thomas Freeman from the University of South Florida agreed
that there were risks to the control group, such as side effects of
the general anaesthetic: "The
risks of participating in the
placebo group are not trivial."
He believed, however, that the
risks were reasonable in relation
to the possible benefits from the
outcome of the study.
Dr Freeman is not the only
person to use sham surgery.
Researchers at 18 institutions
across the world have outlined
plans for similar clinical trials.
Dr Samuel Ellias at the Boston
University Medical Centre uses
fetal brain tissue from pigs.
"We believe that it is necessary
to do this in a placebo or sham
surgery trial, to make sure
these are not placebo effects," he said.
Researchers carrying out
sham surgery have pointed out
that all clinical trials have been
approved by review boards at
bodies such as the US National
Institutes of Health and the
Food and Drug Administration.
They also argue that subjects in
the trials have decided to participate and that preventing
patients from deciding what
risks they are willing to take is a
direct violation of the principle
of autonomy.
But many researchers are
unhappy with the use of sham
surgery in finding a treatment
for Parkinson's disease. Dr Ruth
Maklin of the Albert Einstein
College of Medicine in New
York has voiced her opposition
to the surgery in the New England Journal of Medicine.
"Performing a surgical procedure that has no expected benefit other than the placebo effect violates the ethical and regulatory principal that the risk of harm
to subjects must be minimised in
the conduct of research," said Dr
Maklin.
Muhunthan Thillai, London
studentBMJ 2000;08:45-88 March ISSN 0966-6494
