Overview:
Gastrointestinal surgery for obesity, also called bariatric surgery, alters the digestive process so as to achieve rapid weight loss. The operations can be divided into three types: restrictive, malabsorptive, and combined restrictive/malabsorptive. Restrictive weight loss surgeries limit food intake by creating a narrow passage from the upper part of the stomach into the larger lower part, reducing the amount of food the stomach can hold and slowing the passage of food through the stomach. Malabsorptive weight loss surgeries do not limit food intake, but instead exclude most of the small intestine from the digestive tract so fewer calories and nutrients are absorbed. Malabsorptive weight loss surgeries, also called intestinal bypasses, are no longer recommended because they result in severe nutritional deficiencies. Combined operations use stomach restriction and a partial bypass of the small intestine.
Am I a Candidate for Weight Loss Surgery?:
You may be a candidate for weight loss surgery if you have:
1. a body mass index (BMI) of 40 or more about 100 pounds overweight for men and 80 pounds for women.
2. a BMI between 35 and 39.9 and a serious obesity-related health problem such as type 2 diabetes, heart disease, or severe sleep apnea (when breathing stops for short periods during sleep).
3. an understanding of the operation and the lifestyle changes you will need to make.
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Types of Weight Loss Surgeries:
There are several types of restrictive and combined operations that lead to rapid weight loss. Each one has its own benefits and risks.
Adjustable Gastric Banding (also known as the LAP-BAND)
In this procedure, a hollow band made of silicone rubber is placed around the stomach near its upper end, creating a small pouch and a narrow passage into the rest of the stomach. The band is then inflated with a salt solution through a tube that connects the band to an access port placed under the skin. It can be tightened or loosened over time to change the size of the passage by increasing or decreasing the amount of salt solution.
Advantages of this weight loss surgery:
• Simple and relatively safe
• Short recovery period
• Major complication rate is low
• No removal of any part of the stomach or intestines
• No altering of the natural anatomy
• Very short recovery periods
Disadvantages of this weight loss surgery:
• About 5% failure rate because of
- Balloon leakage
- Band erosion/migration
- Deep infection
• Identifying patients who will not eat through the operation is difficult
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Roux-en-Y Gastric Bypass (RGB)
This operation is the most common and successful combined weight loss surgery in the United States. First, the surgeon creates a small stomach pouch to restrict food intake. Next, a Y-shaped section of the small intestine is attached to the pouch to allow food to bypass the lower stomach, the duodenum (the first segment of the small intestine), and the first portion of the jejunum (the second segment of the small intestine). This reduces the amount of calories and nutrients the body absorbs. Rarely, a cholecystectomy (gall bladder removal) is performed to avoid the gallstones that may result from rapid weight loss. More commonly, patients take medication after the operation to dissolve gallstones.
Advantages of this weight loss surgery:
• greatly controls food intake, leading to rapid weight loss
• dumping syndrome dumping conditions to control intake of sweets
• reversible in an emergency though this procedure should be thought of as a permanent
Disadvantages of this weight loss surgery:
• staple line failure
• ulcers
• narrowing/blockage of the stoma
• vomiting if food is not properly chewed or if food is eaten to quickly
• weight re-gain is known to happen if dietary changes are not followed long term
This type RNY is not widely done anymore. Most surgeon perform the RNY with the stomach divided with no staple line. Transected means: stomach is completely separated from the new stomach
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Duodenal Switch (also called vertical gastrectomy with duodenal switch, biliopancreatic diversion with duodenal switch, DS or BPD-DS) is performed by approximately 50 surgeons worldwide. It generates weight loss by restricting the amount of food that can be eaten (partial gastrectomy (i.e., partial removal of the stomach along the outer curvature see diagram) and by limiting the amount of food (specifically fat) that is absorbed into the body (intestinal bypass or duodenal switch). This weight loss surgery is more controversial because it has a significant component of malabsorption (bypass of the intestinal tract), which seems to augment and help maintain long-term weight loss. Of the procedures currently performed for the treatment of obesity, it has some powerful and effective components. Due to concerns of possible long-term effects of malabsorption and the technical difficulty involved with this type of weight loss surgery, many surgeons don’t perform it.
Advantages of this weight loss surgery:
• More normal stomach allows for better eating quality, drink with meals
• No dumping syndrome because the pylorus is preserved
• Minimizes ulcer risk
• Very effective for high BMI patients (BMI>55 kg/m2), but can be done on lower BMI just as effectively
• The intestinal bypass is partially reversible for those having malabsorptive complications
• Laparoscopic approach is offered by some surgeons
Disadvantages of this weight loss surgery:
• Chance of chronic diarrhea, possibly more foul smelling stools and gas. This can be due to dieting intake, but for the most part controlled.
• Malabsorption can lead to anemia, protein deficiency and metabolic bone disease in up to 5 percent of patients
• Carbohydrates can be well absorbed and if eaten in significant quantities lead to inadequate weight loss
• This procedure is the most complex surgical weight loss procedure. As with any of the surgeries listed complications can occur in high risk patients.(heart failure, sleep apnea)
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The Sleeve Gastrectomy is a form of restrictive bariatric surgery. During this procedure, the surgeon creates a small, sleeve-shaped stomach. The resulting stomach pouch is larger than that created during Roux-en-Y bypass—about the size and shape of a banana—and because of the odd shape, the intestines do not need to be rerouted.
The sleeve gastrectomy works two ways. While the smaller stomach size helps you feel fuller sooner, the surgery also removes the section of the stomach that produces a hormone related to feelings of hunger. As a less complex procedure, it usually requires a shorter recovery time than bypass surgery.
It was once performed as the first procedure in a two-part treatment that was completed with a gastric bypass. However, recent studies have shown that it is effective as a single process method.