Surgical procedures for obesity (also called bariatric surgery) may be appropriate for some dangerously obese people and may reduce risk factors for heart problems, including high blood pressure, sleep apnea, and diabetes. The object of most bariatric surgeries is to limit the amount food passing through the stomach and intestine.
Experts recommend surgery only for the following:
- Those whose BMI is at least 35 or more or whose weight is about 85 to 100 lb more than ideal.
- Candidates must also have associated psychologic or medical problems that reduce their quality of life sufficiently to warrant the risks of surgery.
- They also must not have succeeded in losing weight through other methods.
Standard Bariatric Surgeries. There are two primary approaches currently being used:
- Vertical Banded Gastroplasty. Vertical banded gastroplasty (VBG) involves creating a hole through both stomach walls and sealing the edges with a staple. This narrows the stomach, similar to a funnel, and allows only small amounts of food to pass through.
- Roux-en-Y Gastric Bypass Procedure. This involves creating a small stomach pouch that serves as a reservoir and connects directly to the intestine (extensive gastric bypass) This procedure also limits the amount of food that a person can consume. It produces greater and more sustained weight loss than VBG, but also is more complicated and carries a higher risk for nutritional deficiencies.
Most people lose about two-thirds of excess weight within two years. Many diseases associated with obesity improve (eg, diabetes, high blood pressure, sleep apnea, joint pain, and incontinence).
Side effects and complications of either or both procedures are common, occurring in 5% to 10% of patients. They include the following:
- Vomiting is the most common. (Persistent vomiting may suggest serious neurologic complications, which are rare.)
- The so-called dumping syndrome is a common unpleasant side effect of the gastric bypass procedure that occurs when food waste moves too quickly through the intestine. Symptoms include nausea, weakness, sweating, and faintness (particularly after eating sweets).
- There is a strong risk for anemia and nutritional deficiencies. Supplements of folate and vitamin B12 may be required.
- There is also a risk for bone loss and osteoporosis.
- There is a significant risk for deep-vein thrombosis (blood clots) .
- Other complications include leakage along the staple line, abscess, infection, obstruction, and over-expansion of the pouch.
Between 10% and 20% of patients need follow-up operations to correct complications. Mortality rates of 0.25% to 2% have been reported from surgery, although these rates are still lower than the morality rates from diseases caused by morbid obesity itself. Other variations and less invasive techniques using laparoscopy are being developed. Patients must still develop a healthy life style after the operation and failure can occur if people cheat the procedure by eating frequent small meals of liquid or soft foods. Follow-up must be life long.
The Lap-Band. A newer procedure called laparoscopic gastric banding (the Lap-Band) usually does not require a major incision and avoids some of the major complications of gastric bypass:
- It employs an adjustable silicone band that is placed around the upper part of the stomach.
- A small balloon-like reservoir attached to the band under the abdominal skin contains saline, which can be added or removed to tighten or loosen the band.
- The procedure restricts the amount of food a person can eat and gives the feeling of fullness.
The band is removable, if necessary; studies to date indicate that the intestinal tract returns to normal afterward. Some studies have reported significant weight loss and improved quality of life with the procedure, including in the elderly. A 2001 analysis of eight centers where it was performed, however, reported a very high failure rate after two years and concluded that it is not, at this time, an effective procedure for severe obesity.
Complications are common and include nausea, vomiting, or both in half the patients and severe heartburn in a third. Device-related complications include band slippage, pouch dilation, or both in nearly a quarter of patients and obstruction in 12%. Very serious complications are rare, but include blood clots, bleeding, infection, pneumonia, and perforation of the stomach.
Gastric Pacemaker. Clinical trials are underway in the US and Europe to test a modified gastric pacemaker as a means of inducing feelings of satiety. The device is inserted into the wall of the stomach. Electrical impulses from the device reduce appetite. Very little is known as to its effectiveness; however, thus far, Italian studies are promising. More research is needed.
Revision date: June 18, 2011
Last revised: by Dave R. Roger, M.D.