FDA Approves Stomach ‘Pacemaker" (re: Gastropares
FDA Approves Stomach ‘Pacemaker’
Updated 3:26 AM ET April 7, 2000
Current quotes (delayed 20 mins.) MDT 56 1/16 1/8 (0.22%)
By LAURAN NEERGAARD, AP Medical Writer
WASHINGTON (AP) - Jennifer Sivils was a healthy mother of three when
suddenly she got a mysterious stomach disorder that literally was
starving her to death. She simply could not hold down any food and
her weight dropped from 157 pounds to 98.
Severe gastroparesis left her stomach unable to churn properly to
move food down the digestive tract. Intravenous nutrition kept her
alive.
But then she got an experimental pacemaker-like device that zapped
her stomach with little electric shocks. She since has regained 22
pounds
and can eat certain foods again.
Swayed by cases like Sivils’, the Food and Drug Administration has
approved the sale of Medtronic Corp.’s Enterra implant for up to
4,000 Americans a year who suffer severe cases of this baffling stomach
disorder.
Enterra is not a cure. But in a small study many implant recipients
dramatically improved, said Dan Schultz, FDA’s director of abdominal
devices.
Some 100,000 people may suffer some degree of gastroparesis. Diabetes
causes many cases, but about a third have no known cause.
In mild cases, the stomach just takes longer to digest food. Eating
smaller portions of easy-to-digest food and certain stomach
medications helps many patients. But people with severe cases cannot
eat, sometimes even drink, because of continual nausea, vomiting and
pain. The sickest survive with feeding tubes inserted into the
intestine or total intravenous nutrition.
The theory behind Enterra: The shocks stimulate nerves lining the
stomach that control how it digests food, said University of Kansas
gastroenterology chief Dr. Richard McCallum, who helped test the
device.
It is the same rationale behind other neurostimulators that ease
tremors by zapping a brain nerve, and ease incontinence by zapping a
nerve that controls the bladder.
The Enterra theory is not proved, Schultz said. Enterra has been
studied on so few people - 33 - that the FDA wonders if a placebo
effect from simply having surgery could explain some of the benefit.
The 33 patients, who all failed gastroparesis medications, on average
vomited 48 times a week before the implant. After surgery, vomiting
episodes averaged 23 times a week when Enterra was turned on and 29
times a week when it was turned off. While patients felt better
regardless, those similar numbers puzzled scientists.
Then the stimulator was turned on again for good, and some patients
steadily improved. A year later, vomiting averaged 10 times a week.
Some patients can eat fairly normally with little nausea while others
had less benefit - "a tremendous amount of variability," Schultz
cautions.
Still, the effect seemed important enough that FDA approved Enterra
on March 31 under a special rule allowing "humanitarian" treatments
for
rare, lifethreatening disorders to sell without extensive clinical
trials. Medtronic disclosed the approval Thursday, saying the device
is immediately available.
Enterra is a battery-powered generator implanted in the abdomen with
an electrode snaked up to the stomach muscle. It emits low-voltage
shocks about once every six seconds. It is a $26,000 operation.
Getting Enterra to market was a battle - an initial study was not
promising and a skeptical Medtronic wanted to pull the plug, McCallum
said.
But desperate patients begged to try Enterra. The FDA offered the
special "humanitarian" review, and McCallum said Medtronic allowed
him and University of Tennessee gastroenterologist Dr. Thomas Abell to
complete the study.
Abell implanted Sivils’ device last August. About a month later, she
started noticing gradual improvement.
She is not cured - she still gets IV nutrition three days a week. But
she eats vegetables and soups without vomiting for the first time in
two years and can play with her children again.
"It’s sad to think you could starve to death here in the United
States because of a disease," said Sivils, 35, of Arkadelphia, Ark.
"I’m so grateful" for the device.