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Weight
Loss Surgery Options
The American Society for
Bariatric Surgery describes two basic approaches that weight
loss surgery takes to achieve change:
- Restrictive procedures
that decrease food intake.
- Malabsorptive procedures
that alter digestion, thus causing the food to be poorly
digested and incompletely absorbed so that it is
eliminated in the stool.
To better understand how weight
loss surgery works, it is important to understand how your gastrointestinal
tract functions.
Vertical Banded Gastroplasty (VBG) is a purely restrictive
procedure. In this procedure the upper stomach near the
esophagus is stapled vertically for about 2-1/2 inches (6 cm)
to create a smaller stomach pouch. The outlet from the pouch
is restricted by a band or ring that slows the emptying of the
food and thus creates the feeling of fullness.
Advantages
- The primary advantage of
this restrictive procedure is that a reduced amount of
well-chewed food enters and passes through the digestive
tract in the usual order. That allows the nutrients and
vitamins (as well as the calories) to be fully absorbed
into the body.
- After 10 years, studies
show that patients can maintain 50% of targeted excess
weight loss.
Risks
- Postoperatively, stapling
of the stomach carries with it the risk of staple-line
disruption that can result in leakage and/or serious
infection. This may require prolonged hospitalization with
antibiotic treatment and/or additional operations.
- Staple-line disruption may
also, in the long-term, lead to weight gain. For these
reasons, some surgeons divide the staple-line wall of the
pouch from the rest of the stomach to reduce the risk of
long-term staple-line disruption.
- The band or ring applied
may lead to complications of obstruction or perforation,
requiring surgical intervention.
- Characteristically, these
procedures, while creating a sense of fullness, do not
provide the necessary feeling of satisfaction that one has
had "enough" to eat.
- Because restrictive
procedures rely solely on a small stomach pouch to reduce
food intake, there is the risk of the pouch stretching or
of the restricting band or ring at the pouch outlet
breaking or migrating, thus allowing patients to eat too
much.
- Around 40% of patients
undergoing these procedures have lost less than half their
excess body weight.
- As is the case with all
weight loss surgeries, readmission to a hospital may be
required for fluid replacement or nutritional support if
there is excessive vomiting and adequate food intake
cannot be maintained.

While these operations also reduce the size of the stomach,
the stomach pouch created is much larger than with other
procedures. The goal is to restrict the amount of food
consumed and alter the normal digestive process, but to a much
greater degree. The anatomy of the small intestine is changed
to divert the bile and pancreatic juices so they meet the
ingested food closer to the middle or the end of the small
intestine.With the three approaches discussed below,
absorption of nutrients and calories is also reduced, but to a
much greater degree than with previously discussed procedures.
Each of the three differs in how and when the digestive juices
(i.e., bile) come into contact with the food.
Since food bypasses the
duodenum, all the risk considerations discussed in the gastric
bypass section regarding the malabsorption of some minerals
and vitamins also apply to these techniques, only to a greater
degree.
Biliopancreatic
Diversion (BPD)
BPD removes approximately 3/4 of the stomach to produce both
restriction of food intake and reduction of acid output.
Leaving enough upper stomach is important to maintain proper
nutrition. The small intestine is then divided with one end
attached to the stomach pouch to create what is called an
"alimentary limb." All the food moves through this
segment, however, not much is absorbed. The bile and
pancreatic juices move through the "biliopancreatic
limb," which is connected to the side of the intestine
close to the end. This supplies digestive juices in the
section of the intestine now called the "common
limb." The surgeon is able to vary the length of the
common limb to regulate the amount of absorption of protein,
fat and fat-soluble vitamins.
Extended (Distal)
Roux-en-Y Gastric Bypass (RYGBP-E)
RYGBP-E is an alternative means of achieving malabsorption by
creating a stapled or divided small gastric pouch, leaving the
remainder of stomach in place. A long limb of the small
intestine is attached to the stomach to divert the bile and
pancreatic juices. This procedure carries with it fewer
operative risks by avoiding removal of the lower 3/4 of the
stomach. Gastric pouch size and the length of the bypassed
intestine determine the risks for ulcers, malnutrition and
other effects.
Biliopancreatic
Diversion with "Duodenal Switch"
This
procedure is a variation of BPD in which stomach removal is
restricted to the outer margin, leaving a sleeve of stomach
with the pylorus and the beginning of the duodenum at its end.
The duodenum, the first portion of the small intestine, is
divided so that pancreatic and bile drainage is bypassed. The
near end of the "alimentary limb" is then attached
to the beginning of the duodenum, while the "common
limb" is created in the same way as described above.
Advantages
- These operations often
result in a high degree of patient satisfaction because
patients are able to eat larger meals than with a purely
restrictive or standard Roux-en-Y gastric bypass
procedure.
- These procedures can
produce the greatest excess weight loss because they
provide the highest levels of malabsorption.
- In one study of 125
patients, excess weight loss of 74% at one year, 78% at
two years, 81% at three years, 84% at four years, and 91%
at five years was achieved.
- Long-term maintenance of
excess body weight loss can be successful if the patient
adapts and adheres to a straightforward dietary,
supplement, exercise and behavioral regimen.
Risks
- For all malabsorption
procedures there is a period of intestinal adaptation when
bowel movements can be very liquid and frequent. This
condition may lessen over time, but may be a permanent
lifelong occurrence.
- Abdominal bloating and
malodorous stool or gas may occur.
- Close lifelong monitoring
for protein malnutrition, anemia and bone disease is
recommended. As well, lifelong vitamin supplementing is
required. It has been generally observed that if eating
and vitamin supplement instructions are not rigorously
followed, at least 25% of patients will develop problems
that require treatment.
- Changes to the intestinal
structure can result in the increased risk of gallstone
formation and the need for removal of the gallbladder.
- Re-routing of bile,
pancreatic and other digestive juices beyond the stomach
can cause intestinal irritation and ulcers.

In recent years, better clinical understanding of procedures
combining restrictive and malabsorptive approaches has
increased the choices of effective weight loss surgery for
thousands of patients. By adding malabsorption, food is
delayed in mixing with bile and pancreatic juices that aid in
the absorption of nutrients. The result is an early sense of
fullness, combined with a sense of satisfaction that reduces
the desire to eat.
According to the American Society for Bariatric Surgery and
the National Institutes of Health, Roux-en-Y gastric bypass is
the current gold standard procedure for weight loss surgery.
It is one of the most frequently performed weight loss
procedures in the United States. In this procedure, stapling
creates a small (15 to 20cc) stomach pouch. The remainder of
the stomach is not removed, but is completely stapled shut and
divided from the stomach pouch. The outlet from this newly
formed pouch empties directly into the lower portion of the
jejunum, thus bypassing calorie absorption. This is done by
dividing the small intestine just beyond the duodenum for the
purpose of bringing it up and constructing a connection with
the newly formed stomach pouch. The other end is connected
into the side of the Roux limb of the intestine creating the
"Y" shape that gives the technique its name. The
length of either segment of the intestine can be increased to
produce lower or higher levels of malabsorption.
Advantages
- The average excess weight
loss after the Roux-en-Y procedure is generally higher in
a compliant patient than with purely restrictive
procedures.
- One year after surgery,
weight loss can average 77% of excess body weight.
- Studies show that after 10
to 14 years, 50-60% of excess body weight loss has been
maintained by some patients.
- A 2000 study of 500
patients showed that 96% of certain associated health
conditions studied (back pain, sleep apnea, high blood
pressure, diabetes and depression) were improved or
resolved.
Risks
- Because the duodenum is
bypassed, poor absorption of iron and calcium can result
in the lowering of total body iron and a predisposition to
iron deficiency anemia. This is a particular concern for
patients who experience chronic blood loss during
excessive menstrual flow or bleeding hemorrhoids. Women,
already at risk for osteoporosis that can occur after
menopause, should be aware of the potential for heightened
bone calcium loss.
- Bypassing the duodenum has
caused metabolic bone disease in some patients, resulting
in bone pain, loss of height, humped back and fractures of
the ribs and hip bones. All of the deficiencies mentioned
above, however, can be managed through proper diet and
vitamin supplements.
- A chronic anemia due to
Vitamin B12 deficiency may occur. The problem can usually
be managed with Vitamin B12 pills or injections.
- A condition known as
"dumping syndrome " can occur as the result of
rapid emptying of stomach contents into the small
intestine. This is sometimes triggered when too much sugar
or large amounts of food are consumed. While generally not
considered to be a serious risk to your health, the
results can be extremely unpleasant and can include
nausea, weakness, sweating, faintness and, on occasion,
diarrhea after eating. Some patients are unable to eat any
form of sweets after surgery.
- In some cases, the
effectiveness of the procedure may be reduced if the
stomach pouch is stretched and/or if it is initially left
larger than 15-30cc.
- The bypassed portion of
the stomach, duodenum and segments of the small intestine
cannot be easily visualized using X-ray or endoscopy if
problems such as ulcers, bleeding or malignancy should
occur.

For the last decade, laparoscopic procedures have been used in
a variety of general surgeries. Many people mistakenly believe
that these techniques are still "experimental." In
fact, laparoscopy has become the predominant technique in some
areas of surgery and has been used for weight loss surgery for
several years. Although few bariatric surgeons perform
laparoscopic weight loss surgeries, more are offering patients
this less invasive surgical option whenever possible.
When a laparoscopic operation
is performed, a small video camera is inserted into the
abdomen. The surgeon views the procedure on a separate video
monitor. Most laparoscopic surgeons believe this gives them
better visualization and access to key anatomical structures.

The camera and surgical instruments are inserted through small
incisions made in the abdominal wall. This approach is
considered less invasive because it replaces the need for one
long incision to open the abdomen. A recent study shows that
patients having had laparoscopic weight loss surgery
experience less pain after surgery resulting in easier
breathing and lung function and higher overall oxygen levels.
Other realized benefits with laparoscopy have been fewer wound
complications such as infection or hernia, and patients
returning more quickly to pre-surgical levels of activity.
Laparoscopic procedures for weight loss surgery employ the
same principles as their "open" counterparts and
produce similar excess weight loss. Not all patients are
candidates for this approach, just as all bariatric surgeons
are not trained in the advanced techniques required to perform
this less invasive method. The American Society for Bariatric
Surgery recommends that laparoscopic weight loss surgery
should only be performed by surgeons who are experienced in
both laparoscopic and open bariatric procedures.

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