of animals on high-fat diets, high amino
acid levels in the blood have been linked
to insulin resistance.
Taken together, these biological
effects seem to give gastric bypass an
edge over stomach banding — in which
doctors insert an adjustable band around
the stomach, constricting it and limiting
how much it can hold at any time. Banding makes a person feel full faster, and
the operation succeeds in many people
because they eat less. But because the
food still takes its normal path through
the digestive system, banding doesn’t
trip hormonal switches the way gastric
bypass does, says Edward Mason of the
University of Iowa in Iowa City, who pioneered gastric bypass surgery for obesity
in the 1960s.
Other studies have proved bypass’s
mettle by pitting it directly against banding. A Swedish study of more than 2,000
obese people who underwent surgery
found that after 10 years, gastric bypass
patients had lost 25 percent of their
body weight, on average, compared with
14 percent among banding patients. The
researchers reported the findings in the
New England Journal of Medicine in 2007.
Bypass’s diabetes-busting ability has
also proved superior. Campos, while at
the University of California, San Francisco, found that type 2 diabetes disappeared in three-fourths of gastric bypass
patients but in only half of those getting
banding. That report appeared in the
February Archives of Surgery.
And the benefits of bypass aren’t
limited to diabetes. The procedure
decreases a person’s risk of heart attack
by about half, Scott reported in June in
Orlando at a meeting of the American
Society for Metabolic and Bariatric Surgery. Isaac Samuel of the University of
Iowa reported at the same meeting that
of 81 migraine sufferers who underwent
gastric bypass, 57 had complete resolution of their migraines after at least a
year. Fifteen others had partial improvement. These findings complement previous studies showing that high blood
pressure falls among bypass patients and
that bypass eliminates or improves sleep
apnea — a breathing disorder linked to
Diabetes switch Gastric bypass outcompetes gastric banding when it comes to reversing type 2 diabetes.
Diabetes reversal with
gastric bypass versus banding
100
Gastric banding
Percent of patients
80
Gastric bypass
60
40
20
0 Within 2 years
of surgery
Diabetes reversal
2 years or more
after surgery
SOURCE: H. BUCHWALD ET AL/AM. JOURNAL OF MED. 2009
long-term health problems — in about
90 percent of patients.
Pulling back
To confer such benefits, though, gastric
bypass must be done well. It’s a tricky surgery that is difficult to master. Scott says
that success rates have risen in recent
decades with the development of a more
experienced cadre of surgeons, hospital
support teams devoted to the patients
and the advent of laparoscopy — in which
the operation is performed using a series
of fingernail-sized incisions.
But the surgery still carries risks, with
most severe problems occurring soon
after the operation. The risk of dying
within a month of gastric bypass surgery, primarily from complications, is
around 2 per 1,000 patients in centers
that do a lot of obesity surgery, data from
the American Society for Metabolic and
Bariatric Surgery show.
“That’s about the same risk as a hip
replacement,” says John Morton, a surgeon at Stanford University School of
Medicine.
Gastric bypass patients risk bloating
and nausea if they eat too much or wash
a meal down with too much fluid. Bypass
also ushers alcohol into the bloodstream
rapidly. In May in Chicago, researchers
from the Karolinska Institute in Stock-
holm reported at Digestive Disease
Week that blood alcohol levels spike
faster and take longer to come down in
gastric bypass patients than in others,
suggesting an increased risk of alcohol
abuse. And studies by Morton have
shown that a 5-ounce glass of red wine
runs up blood-alcohol levels in these
patients to nearly 0.09 percent, over the
legal limit.
Explore more
s Mayo Clinic’s gastric bypass page:
www.mayoclinic.com/health/
gastric-bypass/MY00825
