What Are the Surgical Options?

There are several types of restrictive and malabsorptive operations. Each one carries its own benefits and risks.

Restrictive Operations

Restrictive operations serve only to restrict food intake and do not interfere with the normal digestive process. To perform the surgery, doctors create a small pouch at the top of the stomach where food enters from the esophagus. Initially, the pouch holds about 1 ounce of food and later expands to 2-3 ounces. The lower outlet of the pouch usually has a diameter of only about 3/4 inch. This small outlet delays the emptying of food from the pouch and causes a feeling of fullness.

As a result of this surgery, most people lose the ability to eat large amounts of food at one time. After an operation, the person usually can eat only 3/4 to 1 cup of food without discomfort or nausea. Also, food has to be well chewed.

Restrictive operations for obesity include laproscopic adjustable gastric banding (LAGB) and vertical banded gastroplasty (VBG).

lap-band, lapband

Lap Adjustable Gastric Banding (Lap-band)

In this procedure, a silastic band with an inner balloon is placed around the stomach near its upper end, creating a small pouch and a narrow passage into the larger remainder of the stomach (figure 2). The band is then inflated with a salt solution. It can be tightened or loosened over time to change the size of the passage by increasing or decreasing the amount of salt solution. If needed, the band can be removed and the surgery reversed.

Vertical Banded Gastroplasty

VBG has been the most common restrictive operation for weight control. As figure 3 illustrates, both a band and staples are used to create a small stomach pouch.

Although restrictive operations lead to weight loss in almost all patients, they are less successful than malabsorptive operations in achieving substantial, long-term weight loss. About 30 percent of those who undergo VBG achieve normal weight, and about 80 percent achieve some degree of weight loss. Some patients regain weight. Others are unable to adjust their eating habits and fail to lose the desired weight. Successful results depend on the patient's willingness to adopt a long-term plan of healthy eating and regular physical activity.

Restrictive Procedures Weight Loss Related To:
Surgery Factors		Patient Factors
Meal size restriction		Caloric intake
		Caloric expenditure

A common risk of restrictive operations is vomiting, which is caused when the small stomach is overly stretched by food particles that have not been chewed well. Band slippage, erosion, and saline leakage have been reported after AGB. Risks of VBG include wearing away of the band and breakdown of the staple line. In a small number of cases, stomach juices may leak into the abdomen, requiring an emergency operation. In less than 1 percent of all cases, infection or death from complications may occur.

Malabsorptive Operations

Malabsorptive operations are the most common gastrointestinal surgeries for weight loss. They restrict both food intake and the amount of calories and nutrients the body absorbs.

Biliopancreatic Diversion (BPD)

In this more complicated malabsorptive operation, portions of the stomach are removed (see figure 4). The small pouch that remains is connected directly to the final segment of the small intestine, completely bypassing the duodenum and the jejunum. Although this procedure successfully promotes weight loss, it is less frequently used than other types of surgery because of the high risk for nutritional deficiencies. A variation of BPD includes a "duodenal switch" (see figure 5), which leaves a larger portion of the stomach intact, including the pyloric valve that regulates the release of stomach contents into the small intestine. It also keeps a small part of the duodenum in the digestive pathway.

Biliopancreatic Diversion (BPD)

Malabsorptive operations produce more weight loss than restrictive operations, and are more effective in reversing the health problems associated with severe obesity. Patients who have malabsorptive operations generally lose two-thirds of their excess weight within 2 years.

In addition to the risks of restrictive surgeries, malabsorptive operations also carry greater risk for nutritional deficiencies. This is because the procedure causes food to bypass the duodenum and jejunum, where most iron and calcium are absorbed. Menstruating women may develop anemia because not enough vitamin B12 and iron are absorbed. Decreased absorption of calcium may also bring on osteoporosis and metabolic bone disease. Patients are required to take nutritional supplements that usually prevent these deficiencies. Patients who have the biliopancreatic diversion surgery must also take fat-soluble (dissolved by fat) vitamins A, D, E, and K supplements.

Combined Procedures (Restrictive & Malabsorptive Operations)

Roux-en-Y Gastric Bypass (RYGB)

This operation, illustrated in figure 6, is the most common and successful surgical procedure for long-term weight loss. First, a small portion of the upper stomach is used to create a "pouch" which now acts as the stomach reservoir. This restricts food intake. Next, a portion of small intestine is attached to the pouch to allow food to bypass the lower stomach, the duodenum (first segment of the small intestine) and the first portion of the jejunum (second segment of the small intestine). This bypass reduces the amount of calories and nutrients the body absorbs.

The RYGB is considered the "gold standard" of weight loss surgery. Two years after surgery, 75% of patients have lost excess weight. In addition, 50% of patients maintain weight loss 10 years after the procedure.

RYGB Weight Loss Related To:
Surgery Factors		Patient Factors
Meal size restriction		Caloric intake
Some malabsorption		Caloric expenditure
Decreased appetite

Surgical complications after gastric bypass surgery are related to technique as well as underlying patient disease. Intestinal leakage, acute gastric remnant dilation, obstruction, as well as cardiopulmonary complications such as heart attacks, pulmonary embolus (blood clot to the lung), and pneumonia may occur. The mortality rate after RYGB is 0.5%.

Long-term complications for malabsorptive or combined procedures include weight regain, anemia, and vitamin/mineral deficiency. Short-term complications include hair loss, kidney stones, nausea and vomiting, gallstones, internal hernias and bowel obstruction, and peripheral neuropathy.

RGB and BPD operations may also cause "dumping syndrome." This means that stomach contents move too rapidly through the small intestine. Symptoms include nausea, weakness, sweating, faintness, and sometimes diarrhea after eating. Because the duodenal switch operation keeps the pyloric valve intact, it may reduce the likelihood of dumping syndrome.

The more extensive the bypass, the greater the risk for complications and nutritional deficiencies. Patients with extensive bypasses of the normal digestive process require close monitoring and life-long use of special foods, supplements, and medications. The mortality rate with the Biliopancreatic Diversion (BPD) is the highest of any bariatric procedure at 1.1%.

How Are Outcomes Measured?

Weight Loss
% of Excess Body Weight (EBW) lost
EBW = Actual weight - Ideal weight
BMI before and after
Improvement in obesity related co-morbidities
Quality of life improvement

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