Surgery for Severe Obesity: Drastic Treatment
for a 21st Century Epidemic
Written by: Elliot R.
Goodman, MD (from www.healthology.com)
Introduction
Obesity is the most prevalent metabolic disorder today in the
U.S. Men who are more than 125 percent of their ideal body weight
(IBW) or women who are more than 130 percent of their IBW are
considered obese, while the term clinically severe obesity refers
to individuals more than 200 percent of their IBW or 100 pounds
above IBW. Forty percent of adult Americans are obese, as are 20
percent of American children aged 6 to 18. Three to five percent
of American adults are more than 100 pounds above their IBW. It is
estimated that at any one time, 15 to 35 percent of American
adults are dieting in an attempt to lose weight. Ideal body weight
is calculated from using tables first developed in 1959 by the
Metropolitan Life Insurance Company.
Doctors have developed the term Body Mass Index (BMI) to
account for an individual's height when describing their weight.
BMI is calculated using the formula (weight in kilograms/height in
meters2). Normal BMI is between 20 and 25 kg/m2. An individual is
considered mildly obese with a BMI of 27 to 30, moderately obese
with a BMI of 30 to 35, and severely obese with a BMI in excess of
40. For an adult male of average height, a BMI of 40 corresponds
to approximately 100 pounds above IBW.
The
Medical and Economic Costs of Obesity
Theories blame everything from genetics to sedentary lifestyles
and the glut of fast food for rising weight. But regardless of the
cause, experts on obesity have been forced to acknowledge that for
the majority of obese patients, diet, exercise, and weight-loss
drugs simply do not work, with long-term failure rates above 90
percent.
Obesity is associated with many medical problems. They include
increased risk of heart disease, high cholesterol, high blood
pressure, diabetes, heartburn, gallbladder disease, sleep
problems, and degenerative joint disease. For women, cancers
associated with obesity include: uterine, gallbladder, cervix,
ovary, and breast. For men, cancers associated with obesity are
colon, rectum, and prostate cancer. Many severely obese people are
depressed, experience difficulty with daily activities, and rely
on others for care, transportation, and hygiene. It is thought
that 300,000 people every year die in the U.S. due to the medical
consequences of severe obesity.
The economic cost of obesity is staggering-$30 billion each
year is spent on treating the medical complications of obesity,
with Americans spending another $30 to 50 billion on diets and
other over-the-counter weight-reduction treatments.
The Role of Surgery in Treating Severe
Obesity
Surgery for obesity should be considered a treatment of last
resort after dieting, exercise, psychotherapy, and drug treatments
have all failed. The 1991 National Institutes of Health Consensus
Conference on Gastrointestinal Surgery for Severe Obesity
concluded that "patients whose BMIs exceed 40kg/m2 are potential
candidates for surgery if they desire substantial weight loss
because obesity severely impairs the quality of their lives..." In
certain instances, less severely obese patients (those with a BMI
of between 35 and 40kg/m2 ) may also be considered for surgery.
Included in this category are patients with high-risk comorbid
conditions such as life-threatening cardiopulmonary problems or
severe diabetes mellitus.
There are a number of operations that have been used in the
treatment of clinically severe obesity. They are known
collectively as bariatric surgery, a term coined from the Greek
words for weight and treatment. The surgery, which is becoming
increasingly popular, mirrors the rise in obesity and the failure
of diet, exercise, and weight-loss drugs. Approximately 140,000
weight-reduction procedures are currently performed in the
USA every year, up by 50 percent just five years ago. Eighty
percent of the patients are women; most are middle-aged or
younger.
Intestinal bypass
The intestinal bypass was the first operation performed for
weight loss over 40 years ago. It worked by severely limiting the
length of intestine available to absorb calories from food.
Although patients rapidly lost weight, they also lost essential
nutrients (e.g., vitamins and protein) and often died of liver
failure and malnutrition. The biliopancreatic diversion and a
related procedure, the duodenal switch, are recent modifications
of the intestinal bypass that also cause weight loss by
malabsorption. They allow patients to eat normal size meals, but
still put patients at long-term risk for nutritional
complications. These operations are commonly performed in Europe,
where they were first developed, but have recently been gaining
popularity in the U.S.
Vertical banded gastroplasty (VBG)
The vertical banded gastroplasty (VBG) restricts the amount
of food that can easily pass through the stomach at any one time.
It uses a plastic band and four to six rows of steel staples
around the stomach near the gastroesophageal junction, creating a
small pouch and a narrow passage into the larger remainder of the
stomach. Popular in the past, the VBG now only accounts for around
15 percent of all weight reduction operations performed in the
U.S. each year. Common problems seen with the VBG include an
inability to tolerate solid food, leading to sometimes daily
vomiting. This is due to obstruction at the level of the plastic
band. Patients often resort to eating high calorie liquids or soft
foods, which can pass easily through the band (e.g., ice cream and
milkshakes), and many regain whatever initial weight loss they
experience after the surgery.
Laparoscopic band
Another purely restrictive procedure is the laparoscopic
gastric band ("lap-band"), currently undergoing FDA trials.
Laparoscopic surgery is "key-hole surgery" using instruments
placed into the abdomen through five or six small incisions. This
band consists of an outer plastic ring and an inflatable
"inner-tube" that contains saline. The inner-tube is attached to a
reservoir and placed under the skin of the abdominal wall. The
band is placed laparoscopically around the top of the stomach just
below the esophagus. The saline can be injected into or removed
from the reservoir to vary the degree of restriction to the
passage of food into the stomach. The "lap-band" therefore works
like a variable version of the VBG. It has yet to complete trials
and is currently only available at a limited number of centers.
Gastric bypass
The current gold standard for the surgical treatment of
clinically severe obesity is the gastric bypass (GB). This
operation was first performed for obesity over 30 years ago and
was developed after surgeons observed massive weight loss in
patients undergoing gastric surgery for ulcers or cancer.
Approximately 75 percent of all operations performed for severe
obesity in the U.S. are now of this type. A small pouch (around 30
cc or one fluid ounce in size) is created by stapling across the
top of the stomach, causing massive restriction in food intake. A
section of the small intestine (two to five feet in length) is
attached to it so that food can bypass the duodenum and the first
portion of the small intestine, reducing calorie and fat
absorption. The opening from the pouch to the small bowel is kept
small (around one-half inch) so that food and fluids can only pass
very slowly into the intestine, again limiting the number of
calories that can be absorbed from food at any one time. GB
surgery has been shown to induce greater weight loss than the VBG
in several large trials.
Gastric bypass surgery can now be done laparoscopically.
Laparoscopic GB surgery is technically difficult surgery and
surgeons require special skills and training to perform it safely.
Its relative benefits over the "open" or conventional approach
include a lower rate of wound infection, less postoperative pain,
smaller scars, and a slightly shorter period of hospitalization
and recuperation after surgery. It does, however, carry a higher
risk of leaks from the staples holding the pouch and small
intestine together, particularly if the surgeon has only performed
a limited number of the procedures. The risks of laparoscopic GB
are greater in patients with higher BMI, although some surgeons
have reported safe performance of the procedure in patients with
BMIs in excess of 60.
Benefits and Risks of Bariatric Surgery
On average, most patients can expect to lose 75 percent of
their excess weight 12 to 18 months after GB surgery. At East
Carolina University School of Medicine, in Greenville, NC, a
research team led by Dr. Walter Pories has kept records on 608
patients and found that almost 90 percent of initial weight loss
can be maintained for more than a 14-year period.
Physical benefits
Physically and emotionally, the benefits are profound.
Diabetes, high cholesterol, and high blood pressure can be cured
in more than 90 percent of patients undergoing successful gastric
bypass surgery. Many breathing problems, including asthma and
sleep apnea (a life-threatening disorder that forces many obese
patients to sleep with oxygen masks) completely disappear after
surgery too. Chronic and painful leg ulcers heal, and patients
enjoy relief from disabling back and leg pains.
Emotional benefits
Patients no longer face the social stigma or the many
indignities attached to obesity. They can begin to enjoy going to
ballgames as now they can squeeze through turnstiles. They can
travel long distances to visit family and friends without having
to pay for two airplane seats. They now find attractive clothes
that fit. Many patients who were on disability can go back to
work. Women who had been infertile because of hormonal problems
linked to obesity find that after successful surgery, they can
have children.
Physical risks
The surgery is not, however, a quick fix or an easy
way out. It is a drastic step, carrying all the pain and risk of
any major abdominal operation. One percent of patients die after
gastric bypass surgery, usually due to surgical, cardiovascular,
or pulmonary complications. Common complications include leaks
from the staples or stitches holding together the stomach pouch
and small intestine (three percent of cases), blood clots in the
legs or lungs (three percent), wound infections (15 to 20 percent)
and incisional hernias (10 to 20 percent). Narrowing of the
connection between the pouch and small intestine due to scar
formation occurs in 15 percent of patients (leading to nausea and
vomiting), but it can normally be treated with endoscopy (an
outpatient procedure wherein a camera on a flexible tube is placed
down the patient's throat and esophagus and into the stomach). An
estimated 10 to 20 percent of patients need follow-up surgery for
complications such as obstruction due to adhesions (bands of scar
tissue in the abdominal cavity).
Gastric bypass surgery can be reversed if necessary (e.g., due
to excessive weight loss or life-threatening nutritional
deficiencies), but this is only needed in less than one percent of
all patients undergoing the procedure. Plastic surgery, to remove
excess skin from the abdomen, arms, and legs may be necessary,
although this typically is only done 12 months or so after gastric
bypass, when the patient's weight has begun to stabilize.
Eating habits
Bariatric surgery forces people to change their
eating habits radically and makes them violently ill if they
overeat. Patients put themselves at lifelong risk for major
nutritional deficiencies if they do not take daily nutritional
supplements. Gastric bypass seems to work in large part by
enforcing a strict low-calorie diet. At first, patients lose their
appetites and cannot eat more than a few bites at a time without
feeling full.
For the first few months, most can only take in 400 to 600
calories a day. If they eat sweets or consume high-calorie drinks
(e.g., regular sodas), most will suffer dumping syndrome, which
occurs when too much food containing sugar or fat passes too
quickly into the small intestine. Dumping causes nausea, weakness,
sweating, faintness, and sometimes diarrhea, and most patients say
it is so awful that they will do anything to avoid it.
Conclusion
After a year or so, as the pouch stretches, most patients can
consume 1,200 calories a day, but we urge them not to exceed that
amount. Initial weight loss can only be maintained if patients do
not exceed this daily calorie limit. It also becomes possible to
cheat. People who nibble cookies or potato chips all day, or sip
milkshakes, can "out-eat the pouch" and get fat again,
particularly if they become immune to the effects of the dumping
syndrome. For that reason, surgeons insist that the operation is
merely a tool to help patients lose weight and that it will not
work if they misuse it. Successful patients are active
participants in the postoperative process and use the operation to
make new and healthy lifestyle choices. Maximum weight loss
requires the introduction of a healthy diet and a regular regimen
of exercise into the lives of patients undergoing gastric bypass
surgery. We stress to our patients the need to walk two miles a
day at least three times a week to ensure optimal results after
the procedure. For more information on obesity surgery, go to www.obesityhelp.com or www.asbs.org.
Procedures offered by Dr Goodman
