Bariatric Surgery

Sometimes obesity cannot be treated by diet and exercise alone. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) says gastrointestinal surgery or bariatric surgery can be the best option for people who are severely obese and cannot lose weight by traditional means or who suffer from serious obesity-related health problems. By severely obese, NIDDK means having a body mass index of over 40, or being at least 80-100 pounds overweight. (Read about "Body Mass Index" "Obesity")

NIDDK says you may be a candidate for surgery if you have:

• a body mass index (BMI) of 40 or more - about 100 pounds overweight for men and 80 pounds for women
• 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) (Read about "Diabetes" "Coronary Heart Disease" "Sleep")
• an understanding of the operation and the lifestyle changes you will need to make.

Surgery basically works by reducing the amount of food absorbed during the digestive process. (Read about "Digestive System") Normally, digestion starts as we chew and swallow our food, and the food moves down the esophagus to the stomach. The stomach can hold about 3 pints of food at one time. When the stomach contents move to the duodenum, the first segment of the small intestine, digestion speeds up. Most of the iron and calcium (Read about "Vitamins & Minerals" "Calcium") in the foods we eat is absorbed in the duodenum. The jejunum and ileum, the remaining two segments of the nearly 20 feet of small intestine, complete the absorption of almost all calories and nutrients. The food particles that cannot be digested in the small intestine are stored in the large intestine until eliminated.

Bariatric surgery alters this process. There are several types of surgery, each with its own benefits and risks. The American Society for Bariatric Surgery (ASBS) says the surgeries fall into different categories:

• Restrictive - Purely restrictive operations only limit food intake and do not interfere with the normal digestive process. To perform the operation, doctors create a small pouch at the top of the stomach where food enters from the esophagus. At first, the pouch holds about 1 ounce of food and later may stretch to 2-3 ounces. The lower outlet of the pouch is usually about ½ inch in diameter or smaller. This small outlet delays the emptying of food from the pouch into the larger part of the stomach and causes a feeling of fullness. After the operation, patients can no longer eat large amounts of food at one time. Most patients can eat about ½ to 1 cup of food without discomfort or nausea, but the food has to be soft, moist and well chewed. Patients who undergo restrictive procedures generally are not able to eat as much as those who have combined operations. Purely restrictive operations for obesity include adjustable gastric banding (AGB) and vertical banded gastroplasty (VBG). In adjustable gastric banding, a hollow band 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 can be tightened or loosened over time to change the size of the passage by increasing or decreasing the amount of salt solution. AGB is usually done via laparoscopy or endoscopy, which use smaller incisions than open surgery. (Read about "Endoscopy") Vertical banded gastroplasty, which uses both a band and staples, is a less commonly used procedure. NIDDK says the success of restrictive surgery depends on the patient's willingness to adopt a long-term plan of healthy eating and regular physical activity.
• Malabsorptive - Malabsorptive surgery limits the amount of calories and nutrients the body absorbs. Malabsorptive surgery impacts the small intestine, where much of our digestion and absorption takes place. This type of surgery can lead to greater weight loss, but also carries a greater risk for nutritional deficiencies. Patients undergoing a malabsorptive type of surgery can often require close monitoring and life-long use of special foods, supplements and medications.
• Combined Restrictive/Malabsorptive Operations - Combined operations are the most common bariatric procedures, according to NIDDK. They restrict both food intake and the amount of calories and nutrients the body absorbs. In the Roux-en-Y gastric bypass (RGB), 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. Gastric bypass surgery can be performed with conventional open surgery. Laparoscopic gastric bypass is an option for some people. You should discuss the best option for your situation with your surgeon. 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. (Read about "Gallstones") In another combined procedure, called biliopancreatic diversion (BPD), the lower portion of the stomach is removed and the small pouch that remains is connected directly to the final segment of the small intestine, completely bypassing the duodenum and the jejunum.

Surgery to produce weight loss is a serious undertaking. Side effects can include nausea, dehydration and constipation. (Read about "Dehydration" "Constipation") Rapid gastric emptying or dumping syndrome is also common, especially if you do not follow your doctor's diet directions. (Read about "Rapid Gastric Emptying") Anyone thinking about surgery should understand what the operation involves. Patients and physicians should carefully consider the following benefits and risks. In some procedures, minimally invasive robotic-assisted surgery is an option. (Read about "Robotic Surgery") It's also important to note that success is possible only with maximum cooperation and commitment to behavioral change and lifelong medical follow-up. (Read about "Learn About Your Procedure")