Laparoscopic
Bariatric Surgery for Morbid Obesity
Obesity
Obesity
became a major health problem throughout the world. Lifestyle changes with
reduced physical activity and increased consumption of high calorie food led to
the obesity pandemic. An individual is considered to be obese if body fat
percentage is greater than 25% in males and 35 % in females. An individual’s
weight should match his/ her height. Body mass index (BMI) is calculated using
body weight and height. Based on BMI we can decide whether an individual’s
weight is ideal, more or less for his/ her height. It is easy to calculate BMI.
BMI
= Body weight in kilograms/ square of height in meters = kg/ m2.
Based on BMI individuals are categorized as below
If your BMI is ≥ 25 kg/m2 (In western countries ≥ 30 kg/m2), then
you are obese. Cut off limits for overweight and
obesity are 23 and 25 kg/m2 in Asians. In western countries these
limits are 25 and 30 kg/m2 respectively. If only BMI
is taken into consideration, muscular individuals will wrongly be categorized
as obese. So other parameters, like waist circumference and waist to hip ratio,
are used to define obesity in addition to BMI. Waist circumference > 80 cm
in females and > 90 in males and waist to hip ratio > 0.8 in females and
> 0.9 in males indicate obesity. These may be better predictors of obesity
than BMI in Asians.
Causes
of obesity
As
the technology is advancing, comfort levels of the humans increased and the
physical activity got reduced. In addition to this, easy availability of
refined foods, fast foods and soft drinks resulted in daily consumption of high
calories. Social and psychological factors also play an important role in food
consumption and physical activity. In 90 percent of individuals obesity is due
to excess eating and reduced physical activity. In remaining 10 percent
endocrine, genetic problems are responsible. Certain individuals gain weight in
spite of eating less. In fact even this limited eating is excess for them. In
these individuals certain percentage of intake is converted into fat due to the
effect of their genes.
When
we eat, food reaches stomach through a long tube (esophagus). How much we can
eat at any given point of time depends on the capacity of stomach and our
appetite. Stomach acts as a grinder and breaks the food particles into small
pieces. From here the food reaches the small intestine. Small intestine has
three parts - duodenum, jejunum and ileum. Most of the digestion of food and
absorption of calories, vitamins and minerals occurs in the proximal small
intestine. Absorbed excess calories are converted into fat and stored in fat
cells.
Figure
1 – Gastrointestinal tract +
Hepatopancreticobiliary system
One
gram of carbohydrate (sugar) has 4 biological calories. One gram of fat (oil)
has 9 biological calories. One biological calorie is equal to one kilocalorie.
Those who indulge in heavy physical activity need approximately 3000 to 3500 Calories of energy per day. While those who lead
sedentary life style need approximately 2000 Calories of energy per day. If
anyone eats more carbohydrates or fats than he/ she needs then the energy
derived from this excess food is converted into body fat. Excess calories
derived from eating sweets, fries, chips, chocolates, pizzas, burgers, biscuits
in addition to routine food, using excess oil in the food, and consuming soft
drinks lead to gaining excess weight. In addition to this, consuming excess
alcohol and lack of physical activity lead to obesity.
Problems
associated with obesity
Obese individuals are at increased
risk of developing type 2 diabetes and hypertension. Their blood cholesterol
levels are usually higher than in non obese. This leads to fat accumulation in
their blood vessels which increases risk of heart attack and stroke. Obese
individuals may have joint pains and osteoarthritis as their joints have to
bare excess weight. In addition they may snore during sleep with brief periods
of cessation of breathing (obstructive sleep apnea) resulting in lack of sleep,
excessive day time sleep. Obese individuals easily become tired and breathless
even with limited physical activity. They are at increased risk of developing
depression, gall stones, hernias etc. Obese females may have irregular periods
and have higher incidence of abortions and difficult labor. Obesity and
associated co-morbid conditions reduces life span by 5 to 20 years.
How
to get rid of excess fat?
Reducing the excess weight is a big
problem for several individuals. Calorie restriction, regular physical activity
and commitment for the first two steps are important. First step is to cut down
the daily calorie intake. Intake of carbohydrates, fats should be reduced. This
means eating snacks like biscuits, cakes, cookies, fruits with excess sugars
like mangoes, grapes, consuming soft drinks, eating potatoes, ice creams, fried
food, sweets, chocolates, chips, tiffins with excess oil like poori, vada,
using ghee or excess oil for cooking should be avoided or reduced drastically.
Total food quantity should be reduced. Water, food with high protein content
like egg white, lean meat, fish, green leafy vegetables and fruits with less
sugar can be taken normally. Fruits and vegetables should be part of your daily
menu. Whole grains should be consumed in place of refined grains. Skimmed milk,
1% fat milk or soya milk should be used in place of milk with high fat content.
Regular walking and regular exercise will result in energy expenditure, weight
loss and maintenance of weight loss. It will take just half minute to eat a
sweet having 200 calories. But to get rid of that energy you need to walk for 1
hr or run for 15 min.
Role
of medicines in the treatment of obesity
There are several anti obesity
medicines in which only orlistat has FDA (Food and Drug Administration)
approval. These medicines are useful to increase the weight loss only in those
individuals who are already losing weight by food restriction and exercise.
Sibutramine, an anti-obesity drug
which act on brain and reduces appetite, is banned in India, USA and other
countries due to its cardiovascular side effects. Side effects of sibutramine
include increased blood pressure, insomnia, headache, constipation, dryness of
mouth, risk of heart attack and stroke. Orlistat prevents absorption of up to
30 percent of fat in food by antagonizing the action of pancreatic lipase
enzyme in digestive juices. It has no effect on digestion & absorption of
carbohydrates. So it is not useful for those consuming excess sugars and eating
very excess fat foods. As certain percentage of fat is not absorbed, side
effects include steatorrhoea (foul smelling sticky stools because of presence
of undigested fat in stools) and sometimes incontinence of stools. According to
several reports orlistat has been implicated in liver failure, acute kidney
injury and pancreatic injury.
Endoscopic
methods of treatment for obesity
Extensive research is
being carried out on endoscopic bariatric procedures as they are more effective
than medicines and probably safer than surgery. Certain procedures like intra
gastric balloon are useful as a bridge to bariatric surgery as they reduce
surgical risk by reducing patient's weight to certain extent before surgery.
Presence of balloon inside the stomach reduces its effective volume. Individual
with intra gastric balloon gets early satiety after taking even small quantity
of food. Initially upper gastrointestinal endoscopy is done to rule out
conditions like reflux esophagitis, hiatus hernia, peptic ulcer disease and
gastric outlet obstruction. Balloon is introduced into stomach and filled with
500 ml normal saline and 10 ml methylene blue solution. Balloon has to be
removed after 6 months. If it is left beyond 6 months there is risk of
spontaneous deflation, intestinal obstruction. If patient has discomfort or
vomiting, it may have to be removed earlier. Intra gastric balloon is not
suitable as a primary bariatric procedure due to its limited durability.
Endoluminal
suturing procedures are used
as early intervention endoscopic procedures in Grade 1 obesity patients who do
not qualify for bariatric surgery. They are also used as revisional procedures
after failed bariatric surgery. They can’t be used as primary bariatric
procedures as the degree of weight loss is inadequate after these procedures.
Endoscopic staplers function similar to adjustable gastric band. These devices
are still in trials. They can be used as primary bariatric procedures in future
if they are successful in trials.
Bariatric
surgery
These are operations performed on
stomach and small intestine. These operations work on the principle of either
reducing the digestion and absorption of food and/or limiting the amount of
food intake at any given point of time. As a result gradual weight loss is
achieved towards ideal body weight.
Majority of the obese individuals fail
to reduce weight by food restriction and regular exercise. Even if they lose weight
initially after diet and exercise regimen, eventually they regain weight.
Inability to control high calorie intake, inability to exercise regularly or
failure to exercise because of joint problems are some of the reasons for
failure. Bariatric surgery is beneficial for such individuals.
Eligibility
for bariatric surgery
Obese individuals with BMI ≥ 32 kg/m2
with at least two significant medical co-morbid conditions or BMI ≥ 35 kg/m2
even without co-morbid conditions are eligible for laparoscopic bariatric
surgeries. In western countries cut off limits of BMI are 35 kg/m2 and
40 kg/m2 respectively. In
Asians with central obesity and at least two significant medical co-morbid
conditions the cut off limit is further reduced to 30 kg/ m2. Higher
BMI increases the incidence and severity of co-morbid conditions. If these BMI
categories are strictly applied to decide patients eligible for bariatric
surgery then many obese individuals will not have effective therapeutic
options.
Obese individuals should have tried sincerely
but failed to reduce weight by food restriction or exercise before taking a
decision to undergo bariatric surgery. They should understand various surgical
options and the need to take precautions in the food intake after surgery.
After bariatric operations they will be on lifelong vitamin and mineral
replacement. They need to be on regular follow up at specified intervals.
Types
of laparoscopic bariatric surgeries
These are divided into following categories.
(1) Purely restrictive operations
Eg – Laparoscopic sleeve gastrectomy
(Lap SG), laparoscopic adjustable gastric banding (LAGB)
(2) Restrictive and mal-absorptive operations
Eg – Laparoscopic roux-en-y gastric
bypass (Lap RYGB - Most popular bariatric surgery)
(3) Mostly mal-absorptive operations
Eg – Laparoscopic long limb roux–en–y
gastric bypass (Lap LRYGB), laparoscopic bilio-pancreatic diversion with
duodenal switch (Lap BPD-DS).
Presence of certain factors makes
patients more or less suitable to one or other type of bariatric surgery. For
example Lap RYGB operation is not suitable in patients who need to take pain
killers on regular basis. Patients at extremes of age, prior abdominal
surgeries with extensive adhesions are suitable to purely restrictive
operations. Patients with large hiatus hernia or paraesophageal hernia, who
cannot come for regular follow ups for band adjustments, who are super obese
are not suitable for LAGB.
Mechanism
of weight loss after bariatric surgery
In restrictive operations the stomach
size is reduced or its size is restricted to receive only small amount of food.
As a result food intake is restricted at any given point of time. These are
effective if BMI is less than 50 kg/ m2. Postoperative food
selection plays a major role in success of restrictive operations. Patients
should be willing to change their food habits after these operations.
In mal-absorptive operations, in addition
to reducing the size of stomach, proximal part of the small intestine where
most of digestion and absorption of food occurs is bypassed so that food will
reach distal part of the small intestine directly. In these operations in
addition to food restriction at any given point of time, digestion and
absorption of food is reduced. These are effective in any obese individual who
is eligible for bariatric surgery. These are complex surgeries and technically
demanding. Vitamin and mineral deficiencies are more after mal-absorptive
operations. Nevertheless they are more effective than restrictive surgeries in inducing
weight loss and they have well defined role as bariatric surgeries.
In restrictive + mal-absorptive operations
like gastric bypass, 50 to 250 cm of proximal intestine is bypassed. In mostly
mal-absorptive operations extensive length of small intestine is bypassed. This
bypass is in addition to a restrictive component created in the stomach.
Bariatric operations act on the root
causes of fat accumulation in the body. Depending on the type of operation
excess weight loss will be 4 to 7 kg per
month. In 6 months to 2 years weight reaches a point nearer to ideal weight.
Weight will not go below ideal body weight usually. So there is no need to fear
that individuals will become skinny.
Unlike in liposuction, excess fat is
not removed in bariatric surgeries. As the metabolism is controlled, excess fat
gradually comes down in due course of time. In liposuction, excess accumulated
fat is removed but main reason for fat accumulation is not addressed. So individuals
may regain weight. Operations aimed at removal of excess accumulated fat are
mainly cosmetic and have important role in specific situations.
Advantages
of doing bariatric surgery by laparoscopic method
Bariatric surgery is performed either
by open method (cutting the tummy) or by laparoscopic method (putting small
holes in the tummy). Compared to normal individuals, obese individuals are at
high risk of developing postoperative lung collapse, lung infections, deep vein
thrombosis (blood clots in legs), wound infections and incisional hernias. Compared
to open surgery, these complications are significantly less after laparoscopic
surgery. After laparoscopic bariatric surgery patient can walk within 2 days,
can go home within 5 days and can resume normal activities in 2 weeks. Cosmetically
it is excellent as only small holes are created to perform surgery. Because of
these uses, laparoscopic method for bariatric surgeries became popular.
For further details or doubts please contact Dr. Amar
Mobile : +91 9676675646
email : amar.venn@gmail.com
website : www.drvamar.com
Mobile : +91 9676675646
email : amar.venn@gmail.com
website : www.drvamar.com
