Adjustable Gastric Banding
What Is Gastric Banding?
Gastric banding is a "restrictive" form of bariatric surgery for the treatment of morbidly obese patients (BMI >40), or for those with severe obesity (BMI >35) who have weight-related comorbidities. Restrictive obesity surgery aims to promote weight loss by restricting the volume of food the stomach is capable of accommodating. Gastric banding achieves this food reduction by through the use of a band placed around the proximal aspect of the stomach, which reduces the the functional size of the stomach to that of an egg. Although functionally similar to vertical banded gastroplasty, unlike gastric stapling, bariatric banding uses no staples, instead a silastic ring is used (about 2 inches in circumference). Unlike gastric bypass, it does not alter the anatomy of the digestive process or reduce calorie absorption in the gastrointestinal tract, and the banding operation is completely reversible. The latest type of stomach banding is adjustable gastric banding (AGB), commonly known as Lap Band. The gastric band in this case is an inflatable silicone prosthetic device which gives medical staff the ability to vary the stomal diameter. Increasing the diameter alleviates vomiting, reducing it limits food intake further. Another bonus of this procedure is that it may be performed via keyhole laparoscopic surgery, which reduces hospital stay, pain at the incision site, and the number of incisional hernias. However, Lap Band does not avoid the general health complications of gastric banding. Adjustable silastic gastric banding was approved in 2001 by the FDA for the treatment of morbid obesity.
What Type Of Lap Band Is Best?
The bariatric surgeon normally decides which brand or type of band is most suitable for the patient. The precise size of the band is typically determined by the size and thickness of the patient's stomach.
How Does Adjustable Gastric Banding Reduce Weight?
The bariatric surgeon places the inflatable silastic band around the stomach creating an hour-glass shape. Food enters the upper part of the stomach, then trickles slowly down through the band-controlled opening into the lower part and then exits as normal into the small intestine. The small pouch at the top of the stomach holds about 50ml of food. This normally fills up with food very quickly, convincing the brain that the stomach is full. This message helps the patient to eat smaller portions and therefore consume fewer calories. Even if the patient wishes to eat more, the small size of the upper stomach pouch can only accomodate a very small amount of food, and excess food swallowed will be vomited.
How Is The Adjustable Gastric Band Inflated?
The silastic band is inflated and adjusted
by introducing isotonic solution or saline via a special needle through
a small access port positioned under the skin. As the fluid reaches the
gastric band, the band swells, increasing the pressure around the outside
of the stomach. This decreases the size of the passage between the upper
and lower pouches and further restricts the movement of food. Conversely,
by removing fluid from the gastric band, pressure is decreased, permitting
faster gastric emptying and a greater food intake.
How Does Gastric Banding Surgery Compare To Stomach Bypass?
Stomach banding does not involve any form
of gastrectomy (as in Biliopancreatic Diversion or Sleeve Gastrectomy
with Bypass), nor does it entail any change in the passage of food through
the duodenum or jejunum. And unlike gastric bypass, stomach banding is
fully reversible, typically done laparoscopically by keyhole surgery,
whereupon the stomach reverts to its regular pre-banded shape and function.
Because there is no malabsorptive element gastric band patients have a
much reduced health risk of nutritional deficiencies or malabsorption
of vitamins/minerals. Thus calcium and B12 supplementation is not mandatory,
as it is after bypass surgeries such as Roux-en-Y or Duodenal Switch.
Also, there is no risk of gastric dumping syndrome, because the intestinal
tract is left intact.
Is Stomach Banding As Effective As Gastric Bypass For Weight Reduction?
In general, the typical gastric banding patient loses 1-2 pounds per week, but weight reduction is faster immediately after surgery. This weekly weight loss adds up to roughly 50 to 100 pounds the first year. Weight loss results for gastric banding are typically less impressive than for bypass surgery, although some evidence suggests that long term weight reduction is not that different. American experience indicates that early weight loss is slower for banding patients than for bypass patients, and that long term "cheating" is easier after Lap Band than after Biliopancreatic Diversion or Roux-en-Y, resulting in less weight being lost. However, in Australia, where Lap Banding accounts for the majority of bariatric operations performed, [according to the Australian Medical Journal 8/06, 9 out of 10 obesity surgeries involve laparoscopic adjustable gastric band], long term weight loss results (after 5 years) for stomach band patients are close to those achieved by Roux-en-Y patients (50-60 percent loss of initial excess weight), althought early weight reduction remains slower.
Does The Position Of The Gastric Band Affect Weight Loss?
Yes. It's vital for the silastic band to be correctly positioned, which typically requires a number of adjustments after the bariatric surgery. Such adjustments (AKA "fills") can be performed using X-ray fluoroscope techniques, to enable the radiologist to view and assess the placement of the band, as well as the tube which connects the port and the band. This technique is always used if the port has partially rotated or if there is excess tissue above the port. The fluoroscopic process involves the patient swallowing a small amount of radio opaque fluid (as in a 'barium meal'), which shows up on the Xray as it passes through the esophagus and through the small stomal passageway between the upper and lower stomach pouches. This allows the radiologist to view the level of restriction to judge if there are potential or developing health complications. These health problems include: dilation of the esophagus, an enlarged pouch, prolapsed stomach, erosion or migration. In some circumstances revisional bariatric surgery may be necessary to remove the band.
Lap Band adjustments may also be done without the use of X-ray fluoroscopy. This is the practice of the biggest bariatric surgery clinic in Melbourne, Australia, where adjustable gastric banding operations have been performed for more than a decade.
What Happens After Gastric Banding Surgery?
After the lap band operation, patients are put on a strict dietary regime. Typically a liquids-only diet, then semi-solid foods and finally solids. The exact type and duration of diet varies according to circumstances (eg. patient condition, surgeon's preference). Some patients report that until their first fill, they can still eat relatively normal portions, due to a lack of restriction in the stomach. It is not uncommon for doctors to recommend a first adjustment up to 8 weeks after surgery to give the stomach enough time to heal. Thereafter, fills and adjustments are performed as required.
Is Post-Op Support Available After Banding?
Yes. All bariatric centers offer post-op support, although facilities and costs vary. Also, some obesity clinics do not offer separate support for banding patients. Instead, they provide general post-op support aimed at both banding and bypass patients. Due to the different post-op issues (eg. involving eating, digestion, nutrition, health complications and rate of weight loss) faced by these patient-groups, this is not a good idea.
What Are The Health Complications Of Gastric Banding?
Possible post-op complications include:
Who Is A Good (And Bad) Candidate For Gastric Banding Surgery?
In general, stomach banding is indicated for people who conform to all the following criteria:
(1) Have a Body Mass Index above 40, or
those with a BMI 35+ with severe co-morbidities, like high blood pressure,
diabetes, sleep apnea, arthritis, or mobility problems.
In general, stomach banding is contraindicated if the surgery represents an unreasonable risk to the patient, or in the following cases: If the patient has any inflammatory diseases of the gastrointestinal passage, such as ulcers, esophagitis or Crohns disease, or any other health conditions which render them poor candidates for general surgery. Gastric banding is also not suitable for anyone with an allergic reaction to materials contained in the band or who have a pain intolerance to implanted devices.
How Did Adjustable Gastric Banding Systems Develop?
The first stomach band was produced in Sweden, in 1985, by Obtech Medical of Sweden, and is referred to as the Swedish Adjustable Gastric Band (SAGB). Then a US company, Inamed Health, designed the BioEnterics ® LAP-BAND ® Adjustable Gastric Banding System. This gastric banding system was introduced in Europe in 1993. When first manufactured, neither of these stomach bands were initially designed for use with laparoscopic keyhole surgery. More recently, in 2000, the first lower pressure, wider, one-piece adjustable gastric band called the MIDband ® was produced in France. This stomach band was designed to be inserted laparoscopically. MIDband ® has rapidly become one of the leading bands placed in France. At present, there are eight manufacturers of adjustable gastric banding systems.
Related Weight Loss Surgery Links:
Guide To Excess
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