Malabsorptive
Procedures – Biliopancreatic Diversion
[This
is for educational purposes only
– at this time we do not offer The Biliopancreatic
Diversion with Duodenal Switch.]
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 greater degree.
Biliopancreatic
diversion with duodenal dwitch
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
1.
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.
2.
These procedures
can produce the greatest excess weight loss because they
provide the highest levels of malabsorption.
3.
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.
4.
Long-term maintenance
of excess weight loss can be successful if the patient
adapts and adheres to a straightforward dietary, supplement,
exercise and behavioral regimen.
Risks
1.
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.
2.
Abdominal bloating
and malodorous stool or gas may occur.
3.
Close lifelong
monitoring for protein malnutrition, anemia and bone disease
is recommended. As well, lifelong vitamin supplement 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.
4.
Changes to the
intestinal structure can result in the increased risk
of gallstone formation and the need for removal of the
gallbladder.
5.
Rerouting of
bile, pancreatic and other digestive juices beyond the
stomach can cause intestinal irritation and ulcers.
Combined restrictive & malabsorptive
procedure
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 NIH, 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 (15cc to 20cc)
stomach pouch. The remainder of the stomach is not removed,
but it 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% to 60% of excess 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.
- 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 15cc to 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 presurgical
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. Dr. Thomas has extensive experience
with advanced laparoscopic techniques, and this is his
preferred method of approach. 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. Dr. Thomas is a full member of the American
Society of Bariatric Surgery and is board certified.
