| Bariatric surgery procedures |
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 Introduction
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The Procedures |
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Malabsorptive
procedures- Biliopancreatic Diversion (BPD) |
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Restrictive
procedures |
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Vertical Banded Gastroplasty |
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Adjustable
Gastric Band |
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Sleeve
Gastrectomy |
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Hybrid procedures
-Gastric Bypass Surgery |
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| Introduction
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 There
are several different types of Bariatric weight loss surgical
procedures, but they are known collectively as 'Bariatric
surgery'. To understand this, the procedures can be grouped
in three main categories below). The three types are:
- Malabsorptive procedures: This surgery does
focus at reducing the stomach size but they mainly
aim on creating malabsorption. i.e. Biliopancreatic
Diversion (Scopinaro procedure - rare)
- Restrictive procedures: This kind of surgery
primarily reduces the stomach size. There are three
ways of doing this:
- Vertical Banded Gastroplasty (Mason procedure,
stomach stapling)
- Adjustable gastric band (or "Lap Band")
- Sleeve gastrectomy
- Hybrid procedures: In this type, both the
techniques of restriction and malabsorption are applied
simultaneously. i.e. Gastric bypass surgery, like
Roux-en-Y gastric bypass
In this section, we will discuss all the procedures
but only a surgeon can decide which one is suited
the best for patient. Infact he is the only person
who can tell whether the case could be handled laparoscopically
or should be carried out as open surgery. This section
is dedicated to providing you with the information
to help you get familiar with Bariatric surgery
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| Malabsorptive
procedures |
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| This surgery focuses to reduce the
stomach size but they mainly aim on creating malabsorption.
So if the stomach pouch is smaller in size and if there
is signifcant malabsorption, this will lead to impairment
of nutrition absorption and assimilation. In other words
Malabsorptive procedures alter digestion, thus causing
the food to be poorly digested and incompletely absorbed
so that it is eliminated in the stool. |
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| Biliopancreatic Diversion: (BPD) |
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 The
original version of this procedure (without the duodenal
switch) was developed by Dr. Scopinaro in Italy. This
operation creates an impairment of nutrient absorption
(called "malabsorption") as the primary factor
in weight loss. This is done by removing about 2/3 of
the stomach, and arranging the small intestine so that
the section where food mixes with digestive juices is
fairly short. This surgery is rare now because of problems
with malnourishment. These operations may be more effective
in achieving excellent weight loss in the extremely
obese, but bring with them a higher rate of true malnutrition
(malnutrition is very rare for those who undergo standard
gastric bypass).
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| Restrictive
procedures |
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| There are several different types
of Bariatric weight loss surgical procedures. Restrictive
procedures are surgical procedures which primarily reduce
the stomach size. They can be done in three ways. So the
three surgical ways are: |
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- Vertical Banded Gastroplasty (Mason procedure,
stomach stapling)
- Adjustable gastric band (or "Lap Band")
- Sleeve gastrectomy
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| Vertical
Banded Gastroplasty (VBG): |
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 This
operation emphasizes the volume restriction aspect of
calorie control, by creating a tiny stomach pouch that
exits into the lower stomach through a small fixed outlet
that is reinforced by a permanent calibrated band on
the stomach outlet. The operation was devised by Dr.
Mason, one of the original Gastric Bypass surgeons,
as he sought to devise the safest and most straightforward
operation for morbid obesity. It is now an outmoded
procedure because long term studies have demonstrated
that it does not maintain weight loss as well as the
Roux-en-Y gastric bypass.
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Adjustable
Gastric Band
The Laparoscopic Adjustable Silicone Gastric Band (LapBand®,
Inamed) was approved by the FDA in June 2001, for use
in treatment of Severe Obesity. The Lap-Band is a device
designed to produce a small upper gastric pouch, and
a narrow opening from it into the lower stomach. Surgeons
use a silicone band to create a small pouch using the
top part of the existing stomach. This limits food consumption
without disrupting the normal progression of food through
the digestive tract. It causes a sense of fullness after
only a few bites of food, and it helps make the decision
to reduce food intake, and to lose weight. It can be
inserted laparoscopically. The biggest advantage is
that it is a reversible process. This operation is especially
attractive to persons who can spare only a small amount
of time, and who need to return quickly to full activity.
With one to two days hospitalization, a busy executive
can return to his desk, and gain control over troublesome
weight problems.
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| "Removable" in the list
of key features refers to the fact that the Lap-Band can
be removed from the patient with little residual impact
on the stomach. This seems to be true even when the band
has eroded into the stomach, or become infected, or slipped
out of position. This is possible because the substance
from which the band is made creates essentially no tissue
reaction, so that the Band is not stuck in place over
time. This feature also means that the Lap-Band procedure
is "reversible" in a certain sense. We hasten
to clarify that the Band would only be removed in our
practice because of medical necessity, and that if it
were not replaced by some other weight loss procedure
that the patient would be guaranteed to experience significant
weight regain. |
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| This surgery as explained before,
involves placement of a band around the outside of the
upper stomach, to create an hourglass- shaped stomach,
and to produce a small pouch with a narrow outlet. The
special device used to accomplish this is made of implantable
silicone rubber, and contains an adjustable balloon, which
allows us to adjust the function of the band, without
re-operation. Using thin surgical instruments and a small
internal camera to monitor the operation, the surgeon
places a silicone band without cutting or stapling. This
pouch later limits the patient's food consumption without
disrupting the normal progression of food through the
digestive tract. |
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| In some cases, the gastric band is
connected via a small tube to a small reservoir that contains
saline. This reservoir is placed under the skin of the
upper abdomen. After surgery, the surgeon will |
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 examine
the patient to ensure that the band contains enough saline.
It needs to be tight enough to allow for gradual weight
loss while ensuring that the patient eats enough food
for proper nutrition. Adjustments are typically made to
the band one month after the procedure. Using a fine needle,
the surgeon can add or remove saline to enlarge or shrink
the band. The number of adjustments varies from person
to person, but most patients need three to five before
the band is at the ideal tightness. The length of this
laparoscopic procedure is one to two hours. Because the
stomach is not cut, stapled or opened there is less trauma
to the body. The most common problem is a slippage of
the stomach through the band, causing the upper stomach
pouch to enlarge and obstruct, often requiring a revisional
surgery, which can usually be done laparoscopically. For
best success, frequent adjustments of the band are needed,
and one must learn to change eating behaviour. |
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| Sleeve
Gastrectomy |
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| A variation of the biliopancreatic
diversion includes a duodenal switch. The part of the
stomach along its greater curve is resected. The stomach
is "tubulized" with a residual volume of about
150 ml. This volume reduction provides the food intake
restriction component of this operation. This type of
gastric resection is anatomically and functionally irreversible.
The stomach is then disconnected from the duodenum and
connected to the distal part of the small intestine. The
duodenum and the upper part of the small intestine are
reattached to the rest at about 75-100 cm from the colon. |
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| HYBRID
PROCEDURES |
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| There are several different types
of Bariatric weight loss surgical procedures, but Hybrid
procedures are most commonly performed. In this type,
both the techniques of restriction and malabsorption are
applied simultaneously. I.e. Gastric bypass surgery, like
Roux-en-Y gastric bypass. Now let us see this procedure
in details. |
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| Gastric Bypass Surgery |
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 The
newest and most exciting breakthrough in medical is gastric
bypass surgery. Gastric Bypass is also called "Roux
en-Y" procedure, named after the French surgeon,
Dr. Roux, who first described this reconstruction in the
1800's. The bowel is cut, and reconstructed in a Y configuration,
so that two parts of the GI tract can feed into one. This
surgery involves creating a small (less than one ounce)
vertically oriented stomach pouch, as well as a bypass
of most of the stomach and a varying amount of small intestine.
As a result, weight loss is accomplished both by restriction
of food and by malabsorption of nutrients. The Gastric
Bypass provides an excellent tool for gaining long-term
control of weight, without the hunger or craving usually
associated with small portions, or with dieting. Weight
loss of 80 - 100% of excess body weight is achievable
for most patients, and long-term maintenance of weight
loss is very successful -- but does require adherence
to a simple and straightforward behavioural regimen. |
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| To understand what gastric bypass
surgery is, it is important to know the normal course
of digestion. In normal digestion, food passes through
the stomach and enters the small intestine, where most
of the nutrients and calories are absorbed. It then passes
into the large intestine (colon), and the remaining waste
is eventually excreted. |
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| Now in this surgery, the surgeon staples
across the top portion of the stomach to create a very
small stomach pouch. The surgeon then connects the new
stomach pouch to the small intestine, bypassing some of
the upper and more absorptive part of the small intestine.
The operation is complex and difficult, whether performed
by an open incision, or by laparoscopy. It can be organized
into three steps: |
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- Division or partitioning of the stomach into two
parts - an upper small pouch, and a lower, large pouch.
- Creation of a Y-connection in the small bowel, to
make a new end to connect to the stomach.
- Connection of the new small bowel end to the upper
stomach pouch, to bypass the stomach.
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| The first step is the creation of
a small gastric pouch from the patient's original stomach.
The pouch size is approximately 30-40 cc or slightly more
than two ounces. The pouch is somewhat like an extension
of the oesophagus but, when completed, is completely separated
from the remainder of the stomach. The pouch is created
along the more muscular side of the stomach and thus is
less likely to stretch over time. This is the patient's
new stomach and because it is significantly smaller than
the original stomach far less food can be stored here
before becoming full. In this way the feeling of fullness
occurs much earlier when the patient eats and far less
is eaten for each meal. Most patients who have undergone
the gastric bypass indicate that they are far less interested
in food and that their appetite is vastly diminished. |
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| The next step in the procedure involves
dividing the jejunum i.e. the second segment of the small
bowel approximately 50-100 cm beyond its origin and connecting
the bottom portion to the gastric pouch. Food now travels
from the mouth to the oesophagus, into the gastric pouch
and then immediately into the jejunum or Roux limb. Food
no longer goes to the larger portion of the stomach. None
of the stomach is removed and the secretions from the
remainder of the stomach, now called the gastric remnant,
continued to travel downstream into the first portion
of the small bowel, called the duodenum, and combine with
juices from the pancreatic gland and the liver. |
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The third step in the procedure involves
the reconnection of the bowel (the first 50-100 cm of
the jejunum and the duodenum containing the juices from
the stomach, pancreas, and liver and called the biliopancreatic
limb) to the segment of small bowel that was connected
to the gastric pouch (the Roux limb). It is the distance
between the gastric pouch and the place where the biliopancreatic
limb is connected that determines the length of the bypass
and the degree of malabsorption created by the operation.
This distance is selected based on the patients BMI. The
average length of the small bowel before surgery is thought
to be approximately 18 ft. with the jejunum accounting
for the first 2/5 of the small bowel. The length of the
Roux limb that is created ranges from 75 cm to 180 cm
(3-6 ft). The average time it takes to complete the Laparoscopic
Roux-en-Y Gastric Bypass is approximately 2 hours. If
the patient has gallstones, the surgeon may choose to
remove the gallbladder as a preventative measure since
there is a high incidence of gallstone formation upon
weight loss.
This surgery reduces the amount of food eaten as well
as decreases absorption of the food and calories consumed.
So one will feel full more quickly than when their stomach
was its original size, which reduces the amount of food
the person will eat and thus the calories consumed. Bypassing
part of the intestine also results in fewer calories being
absorbed. This leads to weight loss. There is very little
interference with normal absorption of food since the
operation works by reducing food intake, and reducing
the feeling of hunger. The result is a very early sense
of fullness, followed by a very profound sense of satisfaction.
Even though the portion size may be small, there is no
hunger, and no feeling of having been deprived: when truly
satisfied, you feel indifferent to even the choicest of
foods. Patients continue to enjoy eating - but they enjoy
eating a lot less. Ingestion of concentrated sugar is
also essentially prohibited because doing so results in
"dumping." Dumping is a group of unpleasant
symptoms that resembles food poisoning (nausea, vomiting,
diarrhea, abdominal cramps, flushing, and palpitations)
that occurs when simple sugars enter the small intestine
without first being properly digested by the stomach.
Many people also report diminished appetite after Roux-en-Y
gastric bypass, as well as a change in the taste of food.
These are additional ways the gastric bypass causes weight
loss. Following RNY surgery, patients are at risk for
developing anemia because of poor absorption of iron and
vitamin B12. Therefore, dietary supplementation of these
nutrients is required. Poor absorption of calcium may
also occur. Thus, calcium supplements must also be taken
postoperatively. |
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