Each year, approximately 100,000 Americans undergo bariatric surgery for the treatment of severe obesity. Bariatric surgery is considered for morbidly obese people or for obese people with significant complications of obesity.
Bariatric surgery does not remove fat tissue by suction or excision; rather, it usually involves reducing the size of the stomach. The three commonly used types of bariatric procedures are vertical banded gastroplasty, laparoscopic adjustable gastric banding, and gastric bypass.
Vertical banded gastroplasty. This surgery, also called gastric partitioning, is a gastric restriction procedure that divides the stomach into two sections. A stapling instrument is used to section off a golf-ball-size pouch at the top of the stomach, and an inflexible ring (or band) is put in place to encircle the small opening between the pouch and the rest of the stomach. This procedure allows small amounts of food to pass from the pouch to the remaining portion of the stomach. The likelihood of overeating is reduced because a small quantity of food creates a feeling of fullness. Several studies have shown that vertical banded gastroplasty may result in significant weight loss and improvement in weight-related medical conditions, although there are some side effects and risk, which include deterioration of the band or staple line. More commonly, people who undergo this procedure experience vomiting from overstretching the stomach. The risk of infection or death from complications of vertical banded gastroplasty is less than 1 percent.
Laparoscopic adjustable gastric banding. Approved for use by the Food and Drug Administration in June 2001, this gastric restriction procedure cuts off a portion of the stomach to reduce gastric volume without stapling. Using laparoscopic techniques, an adjustable, hollow, silicone band ("Lap-Band") is wrapped around the upper part of the stomach to create a small pouch. Attached to the band is a flexible tube connected to a miniature access port, which is implanted just beneath the skin of the abdomen. Using this reservoir system, a physician can remove or add saline solution to the band to adjust its fit around the stomach and change the size of the narrow passage that connects the pouch to the lower stomach. Unlike some other gastric surgeries, laparoscopic gastric banding is reversible.
Gastric bypass. This procedure is done in combination with gastric restriction. The volume of the stomach is first reduced by using a stapling tool to create a small upper gastric pouch that is completely separated from the rest of the stomach. The small pouch decreases the quantity of food an individual can comfortably consume. A segment of the small intestine is then surgically rerouted to connect directly to the gastric pouch. This procedure allows ingested food to bypass the majority of the stomach as well as part of the small intestine. Since nutrient absorption takes place in the small intestine, the number of calories available to the body is reduced by limiting both the amount of time food spends there and the amount of the small intestine exposed to food and thus available to absorb it. The risks associated with gastric bypass are similar to those of vertical banded gastroplasty. However, approximately 30 percent of bypass patients also develop nutritional deficiencies. According to clinical studies, gastric bypass is effective for initiating and sustaining weight loss.
