Bariatric surgery is a procedure used to restrict food intake or interrupt the digestive process in patients who are severely obese (typically more than 100 pounds overweight). It is used only after other methods, such as dietary changes, exercise and medication, have failed to bring an individual’s weight under control. 

There are two major types of bariatric surgery:

• Restrictive operations. Reduce food intake by narrowing the passage between the upper and lower parts of the stomach. Adjustable gastric banding, in which the passage is narrowed with a hollow band of silicone rubber, is an example of a restrictive operation.
  
  
• Restrictive/malabsorptive operations. Also called combined operations, these alter the small intestine so that less of it is involved in the digestive process. A Roux-en-Y gastric bypass, in which a small stomach pouch is created and attached to a Y-shaped section of the small intestine, is an example of a combined operation. This procedure allows food to bypass the lower stomach, the duodenum and the first portion of the jejunum.

These surgeries can help obese patients lose significant amounts of weight. However, they present certain health risks such as nutritional deficiencies, infection, blood clots and pneumonia. In some cases, bariatric surgery has led to death. However, death or infection occurs relatively rarely, according to the American Obesity Association.

Patients who have successful bariatric surgery will gradually return to a healthful diet after a period of time. There is no guarantee that patients will keep off the weight they have lost. The best way to increase the likelihood of maintaining weight loss is to eat a healthful diet, exercise regularly and make other physician-recommended lifestyle changes.

Bariatric surgery is a procedure used to treat severe obesity in people who have failed to maintain a healthy body weight through diet, exercise and medication. Although bariatric surgery typically results in greater and faster weight loss than these methods, it is usually considered an option of last resort for most individuals because the surgery itself presents potential health risks.

Bariatric surgery is generally reserved for people who are more than 100 pounds overweight, or have a body mass index (BMI) over 40. BMI is a calculation of a person’s height and weight that is used to determine whether the person is within a normal weight range. A healthy BMI is between 18 and 25. Some people with a BMI of 35 or more will be considered for the surgery if they have certain illnesses that could be improved with weight loss, such as type 2 diabetes, sleep apnea and heart disease.

Researchers recently devised a new scoring system that helps to determine which candidates are at greatest risk of experiencing complications from gastric bypass surgery. However, this tool requires additional study before it can be routinely used by physicians.

Even though research shows that bariatric surgery has tripled among adolescents in recent years, concerns about the potential long-term effects usually preclude them from receiving bariatric surgery. However, it is sometimes considered for severely overweight adolescents who have significant health problems related to obesity (such as type 2 diabetes or heart disease) and for whom weight-loss efforts remain unsuccessful after a period of at least six months. A patient must reach adult height (around age 13 for girls and 15 for boys) before the surgery will be considered.

Some research also suggests that the risk of complications following bariatric surgery increases proportionately for each year of age for individuals over age 60.  

A team of health professionals, including physicians, surgeons, dieticians and psychologists, work together to help determine if a patient is a good candidate for this surgery.

Bariatric surgery promotes weight loss through one of two methods: by restricting food intake or by interrupting the digestive process.

The digestive process begins as soon as a person swallows food. Once the food enters the digestive tract, digestive juices and enzymes begin digestion, and calories and nutrients are absorbed in the small intestine. The food moves down the esophagus and into the stomach, where acid continues to digest the food. In the average person, the stomach can hold about 3 pints of food at one time.

As food is digested, it moves to the first part of the small intestine (known as the duodenum), where bile and pancreatic juices promote digestion and absorption of nutrients including the minerals iron and calcium. Most of the remaining calories and nutrients are absorbed in the final two segments of the small intestine (jejunum and ileum). Any leftover food particles move into the large intestine before they are eliminated from the body.

There are two types of bariatric surgery performed today: restrictive operations and restrictive/malabsorptive operations.

Restrictive operations reduce food intake by narrowing the passage between the upper and lower parts of the stomach. This limits the amount of food that can be held in the stomach (to about one ounce) and delays the passage of food through the stomach. Restrictive operations do not interfere with the normal digestive process.

The two major types of restrictive operations include:

• Adjustable gastric banding (AGB). A hollow band of silicone rubber is placed around the upper end of the stomach. This creates a small pouch and a narrow passageway into the rest of the stomach. Once the band is in place, a connecting tube is used to inflate it with a salt solution. The size of the passage can be altered by increasing or decreasing the amount of salt solution.
  

  

• Vertical banded gastroplasty (VBG). A band is combined with staples to create a small stomach pouch. This procedure is not as common as it once was and typically results in less weight loss than bariatric surgery with a malabsorptive component.

  

The restrictive procedures are often performed using a laparoscope, which involves smaller incisions and shorter recovery time than traditional surgery. 

Malabsorptive operations, also known as intestinal bypasses, alter the small intestine so that much of it is not involved in the digestive process. This reduces the amount of calories and nutrients absorbed from food. Today, experts usually do not recommend these procedures because they can result in nutritional deficits for the patient.

Although pure malabsorptive operations are no longer recommended, many patients undergo a combined restrictive/malabsorptive operation. In fact, these are the most commonly performed bariatric procedures, and they both restrict food intake and the amount of calories and nutrients the body absorbs.

The two major combined operations are:

• Roux-en-Y gastric bypass (RGB). The surgeon first creates a small stomach pouch that is sealed off from the rest of the stomach, restricting food intake. Then, the amount of calories and nutrients the body absorbs is reduced by attaching a Y-shaped section of the small intestine to the pouch. This allows food to bypass the lower stomach, the duodenum and the first portion of the jejunum. In some cases, the gallbladder may be removed (cholecystectomy) to prevent the gallstones that sometimes result from rapid weight loss. The development of gallstones after bariatric surgery can sometimes be prevented with medication.
  

  

• Biliopancreatic diversion (BPD). More complicated than RGB, it involves removing the lower portion of the stomach and connecting the small pouch that remains to the final segment of the small intestine. In this procedure, the duodenum and jejunum are completely bypassed. Although this procedure leads to weight loss, it is not performed as frequently as an RGB because there is a higher risk of nutritional deficiency.

All of these procedures have pros and cons. Restrictive operations are easier to perform and are usually safer than malabsorptive procedures. They can also be reversed and do not create major nutritional deficiencies. However, patients tend to lose less weight after these procedures than after malabsorptive operations, and they are less likely to keep the weight off over long periods of time. Patients may also experience vomiting whenever they eat too much, and the band and tubing are subject to slippage and wear, which may result in the need for a second surgery. In rare cases, infection and bleeding may follow AGB.

Patients who have a combined restrictive/malabsorptive operation tend to lose more weight than those who have purely restrictive operations. In addition, they typically lose weight more quickly and keep more of it off for longer periods of time. The fact that these patients lose more weight may offer added benefits for those with health problems such as high blood pressure (hypertension), sleep apnea, type 2 diabetes and osteoarthritis.

However, these procedures are more difficult to perform than purely restrictive operations and are more likely to cause long-term nutritional deficiencies in patients, particularly iron and calcium deficiencies. This means that many patients (especially menstruating women) are likely to develop anemia. All bariatric surgery patients are more likely to develop osteoporosis and other bone diseases. Nutritional supplements may help prevent these disorders. Patients who have RGB or BPD surgery may also suffer from dumping syndrome, which occurs when a meal high in simple carbohydrates (e.g., bread) moves too quickly through the small intestine, leading to nausea, bloating, abdominal pain, weakness, sweating, faintness and diarrhea. Patients are also at risk for developing an infection or abdominal hernia.

Patients usually are urged not to have bariatric surgery unless the health risks of obesity are greater than the risks of having the surgery. Deaths and other illness have occurred as a result of these surgeries. However, the risk of death or infection is relatively low, according to the American Obesity Association. Research from the International Bariatric Surgery Registry (IBSR) show that death within 30 days of surgery occurs in less than one-quarter of 1 percent (0.17 percent) of all vertical banded gastroplasty and Roux-en-Y gastric bypass surgeries.

Prior to the surgery, patients are encouraged to follow all preparatory steps recommended by their physician. These may include modifications to diet, engaging in an exercise program and limiting or stopping use of nicotine products.

Following surgery, patients will have a short hospital stay. The length of the stay will depend on the type of surgery performed and the patient’s recovery. Patients will be placed on a special diet for several months that begins with liquids and progresses through pureed foods and soft foods before returning to regular foods.

Patients will initially find that they need to eat very small meals throughout the day, although the stomach will stretch a small amount over time. However, the amount of food a patient can eat is permanently restricted following surgery. 

For the first six months following surgery, patients often find that they may vomit or feel pain under the breastbone if they eat too much or eat too quickly. Patients may experience other symptoms during this period as well, including:

• Body aches
• Feeling of tiredness similar to flu
• Feeling cold
• Dry skin
• Hair thinning or hair loss
• Mood changes

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to bariatric surgery:

1. Am I a good candidate for bariatric surgery?
   
   
2. Which type of bariatric surgery is best for me?
   
   
3. Can you please describe the procedure to me in detail?
   
   
4. What are the risks associated with bariatric surgery?
   
   
5. How will my eating habits change following bariatric surgery?
   
   
6. Will I have to exercise regularly after bariatric surgery?
   
   
7. How much weight can I expect to lose with bariatric surgery?
   
   
8. Is there a chance I will gain the weight back at a later date?
   
   
9. How can I increase my chances of keeping off the excess weight?
   
   
10. How long is the recovery period after bariatric surgery?