Morbid obesity is a serious and underestimated
medical condition. It is defined as a condition in which the patient
is 80% or 45kg above ideal body weight. It can cause many medical
illnesses (co-morbidities). The incidence of obesity is increasing
rapidly in the Australian population with up to 20% of people
considered to be seriously over weight and 6% morbidly obese. The
cost of treating obesity related medical illnesses in Australia is
in the order of 5 billion dollars per year. Morbid obesity causes a
significant reduction in the quality of life for those afflicted by
it. A basal metabolic index (ratio of body weight to body surface
area in square metres) of 40 or over indicates morbid obesity. A BMI
of greater than 35 is considered to indicate a serious weight
problem and is the minimum level at which surgery is considered an
option. Patients suffering from morbid obesity statistically lose
between 15 and 20 years of their life span. This is because obesity
can cause many medical problems including:
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Diabetes
-
Hypertension
-
Heart disease
-
Sleep apnoea
-
Osteoarthritis of weight bearing joints
-
Hiatus hernia and gastro-oesophageal reflux
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Gall stones
-
Infertility
-
An increased incidence of carcinoma of the
breast and prostate.
The sufferer's quality of life can be poor. Low
self-esteem and depression are common. Where the patient has
suffered from morbid obesity for more than 5 years despite all
attempts to control it by conservative means and, where they are
strongly motivated to lose weight, then surgery is an option.
Patients electing to undertake a surgical solution to their
problem must be aware that surgery for morbid obesity is not always
successful. The surgery can fail due to technical factors such as
breakdown of a staple line, erosion of a gastric band or development
of an unexpected complication.
Another major cause of problems after surgery is the inability of
the patient to comply with the instructions given to them at the
time of surgery. For example, continuing to eat high calorie, semi
liquid foods like ice cream and chocolate after gastric banding or
stapling or not taking vitamin and mineral supplements after
biliopancreatic diversion can lead to failure or complications.
For these
reasons patients should select surgery if they feel it is the only
way that they can control their weight problem. They must accept
that despite their surgeons best efforts, in a minority of cases the
surgery may not be a success and that complications are possible.
Surgery on the other hand, is the most successful treatment that we
have for patients suffering from the debilitating illness of morbid
obesity as conservative weight reduction programs have only limited
success rates.
SELECTION AND REFERRAL OF PATIENTS FOR SURGERY
- Patients
should be in the vicinity of 80% or 45kgs above ideal body weight
(BMI 40 or above) or have a BMI of more than 35 and have medical
or psychological conditions that would benefit from weight
reduction.
- They must
have been overweight for at least 5 years.
- They must
have tried and failed to achieve sustained weight loss by
conservative means.
- They must
be strongly motivated to lose weight and be prepared to make the
necessary sacrifices to achieve such an end.
- They must
be fit to undergo surgery and be informed of the effects and
complications.
- They must
be prepared to attend for continuing supervision as a lifelong
commitment.
- Should be older than 15 years of age and Less than 70.
A BRIEF HISTORY OF THE DEVELOPMENT OF OBESITY SURGERY
The attempts
to surgically control obesity began in the 1960s. Since then many
different techniques have been used with variable success rates. All
have used one or both of the methods mentioned above. There was a
high failure and complication rate in the early years, partly
because of technical failure, but often because of poor patient
compliance and loss of motivation. The uncertainty of the success
rate and the incidence of serious complications in early cases has
led to a poor acceptance of surgery as a legitimate method of weight
control by the medical community. However, techniques are improving
and bariatric surgeons are becoming more experienced, so that
results have improved markedly over the last decade. Surgery is
often the only option for the seriously obese patient who, for
various reasons, has failed to lose weight on diet and exercise
programs.
Small bowel
bypass
Surgery for obesity began in the 1960s with the introduction of
small bowel bypass. This produced a mal-absorptive state and massive
weight loss by reducing the functional length of the small bowel
from the normal 7.5m to just over 1m. Unfortunately, although weight
loss was excellent, follow up revealed a number of serious
complications including septicaemia, liver failure, calcium loss
causing bone softening, renal stones and intractable diarrhoea. For
this reason the procedure fell from favour and the focus turned to
the restrictive procedures.
Gastric
bypass
Gastric bypass was developed by Professor Edward Mason in Iowa,
USA in 1966. He had noted the weight loss that occurred after
partial stomach removal for cancer or ulcer and attempted to use the
principal of reducing the stomach volume to induce weight loss.
The stomach
was stapled across so as to reduce its volume to 10% of normal. The
small pouch so produced was attached to the upper small bowel with a
1cm. opening (stoma) between the two, a procedure known as gastric
bypass. The weight losses achieved were encouraging and many centres
still perform this procedure regarding it as the gold standard as
far as weight reduction procedures are concerned. It is a
technically difficult procedure with some risk of leakage and
abscess formation at the anastomoses (joins) between the small bowel
and stomach and between the loops of intestine. It is now possible
to be performed laparoscopically in suitable cases. In the long term
there is a failure rate for gastric bypass as a result of dilatation
of the stoma or break down of the staple line. These problems result
in an increase in the speed at which the pouch empties and so lead
to loss of restriction and increased food intake with resultant
weight gain.
Gastric
Stapling Procedures
Dr Edward Mason suggested the creation of a small upper
stomach pouch by placing a stapled partition across the stomach with
an opening in it. This was designed to allow food to drain slowly
into the lower stomach pouch producing fullness and the inability to
more than a small amount of food. Operations of this type are
commonly referred to as gastric stapling procedures. Food would pass
through the narrow opening in small amounts and then on through the
normal digestive pathway so minimizing the mal-absorption of
nutrients such as iron and B12. X-ray or endoscopy could still be
used to inspect the lower stomach via the stoma.
The earliest
of these procedures were simple linear staple lines in which a 1cm
gap was left. Many of these procedures failed because of widening of
the opening between the pouches (stomal dilatation) or staple line
break down. These problems allowed the patient to return to normal
eating volumes and caused weight regain. The high failure rate of
these early procedures has been largely responsible for the poor
reputation of bariatric surgery. Many modifications have been
introduced to overcome these problems. The most successful of these
techniques available today is probably the vertical banded
gastroplasty of Mason. This procedure seeks to overcome pouch
dilatation by constructing the 15cc pouch vertically along the thick
walled lesser curvature of the stomach, placing four lines of
staples and strengthening the stoma by wrapping it in a nylon mesh
collar to prevent dilatation. The procedure is still rather complex
and requires the use of both a linear and a circular stapler.
In the Mason procedure a rigid tube 1cm in diameter is
passed into the stomach. A circular staple gun is fired
against the edge of the tube cutting a hole that fixes the
front and back walls of the stomach together. A four line
staple gun is then passed through this opening and fired
parallel to the tube to produce a pouch. The opening is
then wrapped in a mesh collar to stop the opening dilating
and the pouch emptying too rapidly. Failure occurs due to
breakdown of the staple line and dilatation of the pouch.
The mesh can erode into the stomach allowing the stoma to
dilate or enlarge.
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Figure 1 - VERTICAL BANDED GASTROPLASTY
There is some risk of leakage postoperatively at the site of the
junction of the two staple lines and there are still long term
failures due to staple line break down, pouch dilatation and erosion
of the mesh into the gastric lumen resulting in stomal dilatation.
The other major cause of long-term failure is failure of patient
compliance and the patient adopting a diet high in foodstuffs such
as chocolate and ice cream. These liquefy in the pouch passing
rapidly through the stoma without producing satiation and so result
in a high intake of kilojoules and weight regain. Continued
ingestion of these semi-liquid sweet foods is one of the major
causes of failure in all gastric reduction surgery.
The surgeon
has only two proven methods available to him to induce weight loss:
- By
restricting gastric capacity and so reducing the amount of food
that a patient can ingest, the so-called gastric restrictive
procedures.
- By changing
the intestinal tract so as to prevent the food eaten from being
digested and absorbed, the so-called mal-absorptive procedures.
I mainly offer three
forms of surgery to my
patients. They are:
I am also beginning to perform small numbers of Fobi
pouch gastric bypasses; both open and laparoscopically in specific
circumstances such as failed gastric bandings and people who cannot
travel to Sydney for band adjustment. My experience in this
procedure is still very small but encouraging.
These are different approaches to the problem and
I shall attempt to explain the advantages and disadvantages of each.
In the end, the patient must consider which approach they feel will
be most tolerable to them. For example, if considering gastric
banding, can they tolerate small measured meals, can they avoid
sweets or can they adopt the slow eating and careful chewing that is
necessary to make the procedure work?
My preference is to consider the simpler technique of banding as a
first option unless the patient:
- has had
partitioning surgery before which has not controlled their weight
- is
super-obese (>125% above ideal bodyweight)
- has
diabetes or very high cholesterol
- does not
feel they can control sweet intake and food volumes
- has a
severe reflux problem with a large hiatus hernia.
In these cases I feel biliopancreatic diversion is more likely to be
successful.
I strongly advise all patients considering all these types of
procedure to talk to other patients about their experiences with the
surgery and their satisfaction with the procedure in general.
LAPAROSCOPIC ADJUSTABLE SILICONE GASTRIC BANDING
In an effort to simplify the procedure of gastric reduction, Molina
in Houston and Kolle in Oslo, in 1980 introduced the concept of
gastric banding. The band wrapped around the upper part of the
stomach (the fundus) and produced a small pouch of between 30 and 15
cc without the use of staples or sectioning of the stomach. The
procedure is fully reversible. The initial bands of Dacron arterial
graft were fixed in circumference. In 1986, Kusmak in New Jersey and
Halberg in Sweden, introduced bands that could be adjusted via a
balloon on their inner surfaces. The American version is referred to
as the Lap Band or LAGB and the Swedish version as the Swedish
adjustable gastroplasty band or SAGB. The balloon on the inner
surface of these bands allows the diameter of the stoma to be
changed so as to alter the rate at which the pouch empties so
altering the feeling of fullness or satiation after eating. This
adjustability allows fine tuning of the procedure postoperatively.
Adjustment is achieved by injecting or aspirating saline or an X-ray
contrast medium called Isovue into an injection port sited in the
abdominal muscle. These devices have now been modified so as to
allow them to be placed laparoscopically with benefits to the
patient in terms of reduction of postoperative discomfort, increased
speed of recovery and reduced scarring. They are the only adjustable
form of partitioning currently available.
Patients who are addicted to sweet foods and drinks, who have a
severe reflux problem and who are clinically depressed, are often
unsuitable for gastric banding procedures.
Click on the image to englarge
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Figure 2 ADJUSTABLE SILICONE GASTRIC BANDING
Laparoscopic gastric banding is my preferred method of gastric
partitioning.
I have a preferring to
Bioenterics Lap
Band System. The procedure is conducted
under a general anaesthetic. Five small incisions are made in the
abdominal wall and the abdomen inflated with CO2 gas. The band is
passed around the upper stomach 2-3cm from the junction of the
gullet and the stomach so as to produce a 15ml pouch. The band is
connected to a device called an access port into which fluid may be
injected to tighten the band. The procedure takes up to two hours
and the patient must remain in hospital 2-3 days after surgery. The
procedure is simple, reversible and adjustable but to be successful,
the patient must comply with certain eating disciplines if the
procedure is to produce the desired weight loss.
They must:
1. Adhere to a diet of easily masticated foodstuffs
such as cereal, vegetables and white meats.
2. They must measure their food volumes and eat no
more than an entrée sized helping per sitting.
3. They must chew every mouthful of food thoroughly
and eat slowly .
4. They must avoid high kilojoule semi liquid foods
such as ice cream and chocolate.
5. They must avoid eating when upset or rushed.
6. They must take multivitamins and occasionally
iron to supplement their diet.
7. They should avoid eating and drinking at the
same time.
8. They should have six monthly blood counts to
check haemoglobin, iron, B12 and folic acid levels.
9. Regular exercises is Mandatory.
Patients must be aware that complications can occur
both at the time of surgery and later. Detailed information on
laparoscopic gastric banding and its potential problems and
complications, is available on my website.
Briefly the following problems can occur:
-
At surgery tearing of the stomach and bleeding from
the spleen are the chief concerns. Fortunately the incidence of
these problems is low in my experience of 610 cases. I have had
only one easily repaired gastric puncture in my series. However,
if such a problem occurred and was unable to be treated
laparoscopically then conversion to open surgery to control the
damage and complete the procedure might be necessary.
-
Open operation may also be required if there are
technical difficulties such as a grossly enlarged and
fat-infiltrated liver, that prevents access to the site where the
band is positioned or because of the presence of widespread
adhesions.
-
Postoperatively there is a risk of slippage of the
band down the stomach or of stretching of the pouch. Both of these
problems cause poor drainage from the stoma leading to excessive
vomiting and acid reflux. If these problems do not respond to
deflation of the band then operative re-positioning or removal of
the band may be necessary. There is a 3.5 % incidence of slippage
in my series.
-
Erosion of the band into the stomach can occur in
2.5 % of cases. This complication requires removal of the band. It
can be replaced after an interval of 3-6 months. If it erodes
again then the patient is considered unsuitable for gastric
banding. Avoidance of over filling of the gastric pouch or having
the band too tight can help prevent this problem.
-
The access port can drop into the abdominal cavity
if the muscle layer tears, the device can become rotated in the
muscle layer or the tubing can tear away from the port. These have
occurred in 3.5 % of cases and the problems have required minor
procedures to correct the situation.
-
The best way to avoid these problems is to adhere
to the eating regimen detailed above. With discipline, excellent
weight reduction can be achieved with patients losing an average
of 35kg or 53% of excess body weight and some much more. Some
patients, however, cannot exercise the necessary restraint or have
trouble accepting the restrictions and with these patients, a
different approach is required.
Link to:
Patient Information on Laparoscopic Gastric Banding for Obesity
BILIOPANCREATIC DIVERSION
Biliopancreatic diversion was developed by Professor Nicola
Scopinaro from Genoa, Italy. It is a form of gastric bypass but
combines mal-absorption of fats and starches with temporary gastric
restriction. This is achieved by reducing the stomach capacity to
250-400cc and connecting the stomach pouch to the lower 2.75 metres
of the small intestine. 4-metres of the small bowel is bypassed.
This bypassed bowel carries the bile and pancreatic juices that are
responsible for digesting the fat and starch in the food that we
consume. A new opening is made between these two loops only 50-75 cm
from the point where the small bowel joins the colon. This means
that the ingested fat and starches are not digested as these juices
(enzymes) only blend with the food over this short distance instead
of the full 7-metre length the small bowel and therefore,
approximately 80% of ingested fats and starches are not absorbed.
This results
in good weight control. Patients initially find they cannot eat a
great deal, which aids weight loss, but as time passes they usually
are able to eat normal sized meals of most types of food.
BPD does not
depend purely on gastric restriction in the long term relying more
on the mal-absorption to sustain weight reduction. The
mal-absorption does however have side effects. These include more
frequent smelly bowel motions and the loss of nutrients that are
normally absorbed with the fat that a patient eats. These include
Vitamins A, D, E & K. The duodenum is bypassed so calcium and iron
are not well absorbed. It is essential that patients undergoing BPD
commit to taking vitamin and mineral supplements life long so as to
avoid deficiencies in these nutrients. Sunshine is also important to
help maintain Vitamin D levels. Protein absorption is poor so at
least 100g of high quality protein must be eaten daily and fats must
be strictly avoided. Fats are not absorbed and convert to oil
leading to diarrhoea, incontinence and loss of nutrients. If you
experience these side effects, try taking a course of Xenical.
Despite its apparent downside, the surgery is usually well tolerated
and produces excellent weight reduction.
Link to: Patient Information on Biliopancreatic Diverson
___________________________________________________________
Gastric Bypass
Is discussed elsewhere in this website,
Click here to go to that section.
