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Gastric Bypass, Roux en-Y (Proximal) is the most
commonly employed gastric bypass technique, and
is by far the most commonly performed bariatric
procedure in the United States. It is the
operation which is least likely to result in
nutritional difficulties. The small bowel is
divided about 45 cm (18 in) below the lower
stomach outlet, and is re-arranged into a
Y-configuration, to enable outflow of food from
the small upper stomach pouch, via a "Roux
limb". In the proximal version, the
Y-intersection is formed near the upper
(proximal) end of the small bowel.
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The Roux limb
is constructed with a length of 80 to 150 cm (30
to 60 inches), preserving most of the small
bowel for absorption of nutrients. The patient
experiences very rapid onset of a sense of
stomach-fullness, followed by a feeling of
growing satiety, or "indifference" to food,
shortly after the start of a meal.
Gastric bypass surgery makes the stomach smaller and allows food
to bypass part of the small intestine. You will feel full more
quickly than when your stomach was its original size, which
reduces the amount of food you eat and thus the calories
consumed. Bypassing part of the intestine also results in fewer
calories being absorbed. This leads to weight loss.
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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In a
Roux-en-Y gastric bypass, the stomach is made smaller by creating a
small pouch at the top of the stomach using surgical staples or a
plastic band. The smaller stomach is connected directly to the middle
portion of the small intestine (jejunum), bypassing the rest of the
stomach and the upper portion of the small intestine (duodenum).
This procedure can be done by making a large incision in the abdomen (an
open procedure) or by making a small incision and using small
instruments and a camera to guide the surgery (laparoscopic approach).
As performed today, gastric bypass surgery has two
parts:
- Creation of a small
stomach pouch
During this part of the surgery, the stomach is
divided into a large portion, and a much smaller portion. The small part
of the stomach is then sewn or stapled together to make a small pouch
(this part is sometimes called "stomach stapling"). The small stomach
pouch can only hold a cup or so of food.
With such a small stomach, people feel full quickly
and eat less. This strategy is also called "restrictive," since the new
stomach size restricts food intake.
- "Roux-en-Y" creation
(bypass)
In this part of the surgery, the new, small stomach
pouch is disconnected from the first part of the small intestine (the
duodenum). The surgeon then reconnects the stomach to a portion of
intestine slightly further down (the jejunum). This surgical technique
is called a "roux-en-Y."
After a roux-en-Y, food passes directly from the
stomach into the jejunum, bypassing the duodenum. This leads to reduced
absorption of calories and nutrients. This weight loss method is called
"malabsorptive."
Stomach stapling and gastric bypass are typically
performed during the same surgery. Together, this surgery is called a
"roux-en-Y gastric bypass." The roux-en-Y procedure accounts for about
80% of all U.S. weight loss surgery procedures.
Usually, gastric bypass is performed laparoscopically
(using tools inserted through small incisions in the belly). When
laparoscopy is not possible, gastric bypass can be open (laparotomy).
This involves a large incision in the middle of the belly.
Gastric bypass surgery is generally considered when
your body mass index is 40 or higher or you have a life-threatening or
disabling condition related to your weight.
Your doctor may only consider
doing gastric bypass surgery if you have not been able to lose weight
with other treatments.
The following conditions may also be required or are
at least considered:
- You have been obese for at
least 5 years.
- You do not have an ongoing
problem with alcohol.
- You do not have untreated
depression or another major psychiatric disorder.
- You are between 18 and 65
years of age.
All surgeries have risk, and it
is important for you and your health professional to discuss your
treatment options to decide what is best for your situation.
Most people who have gastric
bypass surgery quickly begin to lose weight and continue to lose weight
for up to 12 months. One study noted that people lost about one-third of
their excess weight (the weight above what is considered healthy) in 1
to 4 years.1
Some of the lost weight may be regained.
The laparoscopic approach showed similar results, with
69% to 82% of excess weight lost over 12 to 54 months.
What To Expect After
Surgery
This surgery usually involves a
4- to 6-day hospital stay (2 to 3 days for a laparoscopic approach).
Most people can return to their normal activities within 3 to 5 weeks.
Gastric bypass surgeries may
cause dumping syndrome. This occurs when food moves too quickly through
the stomach and intestines. It causes nausea, weakness, sweating,
faintness, and possibly diarrhea soon after eating. These symptoms are
made worse by eating highly refined, high-calorie foods (like sweets).
In some cases you may become so weak that you have to lie down until the
symptoms pass.
Risks & Complications
Risks common to all surgeries
for weight loss include an infection in the incision, a leak from the
stomach into the abdominal cavity or where the intestine is connected (resulting
in an infection called peritonitis), and a blood clot in the lung (pulmonary
embolism). About one-third of all people having surgery for obesity
develop gallstones or a nutritional deficiency condition such as anemia
or osteoporosis.
Fewer than 3 in 200 (1.5%)
people die after surgery for weight loss.
After a Roux-en-Y gastric bypass
surgery:
- An iron and vitamin B12
deficiency occurs more than 30% of the time. About 50% of those with
an iron deficiency develop anemia.
- The connection between the
stomach and the intestines narrows (stomal stenosis) 5% to 15% of
the time, leading to nausea and vomiting after eating.
- Ulcers develop 5% to 15% of
the time.
- The staples may pull loose.
- Hernia may develop.
- The bypassed stomach may
enlarge, resulting in hiccups and bloating.
In a gastric bypass, the part of
the intestine where many minerals and vitamins are most easily absorbed
is bypassed. Because of this, you may have a deficiency in iron, calcium,
magnesium, or vitamins. This can lead to long-term problems, such as
osteoporosis. To prevent vitamin and mineral deficiencies, you may need
to work with a dietitian to plan meals, and you may need to take
nutrient supplements and injections of vitamin B12.
There is also a possibility that
you may develop gallstones after gastric bypass. Sometimes the
gallbladder is removed as part of the surgery. But if your gallbladder
is not removed, then you may need to take medicine to prevent
gallstones.
Early studies of the
laparoscopic approach to surgery for obesity suggest that it reduces
recovery time and postsurgery complications.
Results and
health benefits of gastric bypass Surgery
Weight loss of 65 to 80% of excess body
weight (the amount by which actual body weight exceeds
actuarial ideal body weight) is typical of most large series
of Gastric Bypass operations reported. The medically more
significant effects are a dramatic reduction in co-morbid
conditions:
- Hyperlipidemia is
corrected in over 70% of patients.
- Essential
hypertension is relieved in over 70% of patients, and
medication requirements are usually reduced in the
remainder.
- Obstructive sleep
apnea is markedly improved with weight loss, so that
most patients are asymptomatic, and often do not even
snore, within one year.
- Diabetes mellitus
type 2 is reversed in up to 90% of patients, usually
leading to a normal blood sugar without medication,
sometimes within days of surgery.
- Gastroesophageal
reflux disease is relieved from the time of surgery in
almost all patients.
- Venous
thromboembolic disease signs such as leg swelling are
typically much improved.
- Low back pain and
joint pain are typically relieved or improved in nearly
all patients.
A recent study in a large comparative
series of patients showed a 89% reduction in mortality
over the 5 years following surgery, compared to a
non-surgically treated group of patients. There were
accompanying decreases in the incidence of cardiovascular
disease, infections, and cancer.
Concurrently, most patients are able to
alter their lifestyle, to consume "healthier" foods,
exercise more regularly, and to enjoy greater participation
in family and social activities. Bariatric surgery is the
most effective treatment for morbid obesity, and can
markedly improve health and lifestyle.
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