Gastric Bypass

This type of surgery typically is performed on patients with a body mass index (BMI) of 40 or more. This measure is a calculation of a person’s height and weight, and a BMI of 40 represents a man who is about 100 pounds overweight, or a woman who is about 80 pounds overweight.

During a gastric bypass procedure, a patient’s digestive anatomy is surgically altered to restrict the amount of food they are physically able to eat at one time. In addition, the digestive tract is altered so that food bypasses part of the stomach and part of the small intestine, resulting in fewer calories being absorbed by the body.

Gastric bypass surgery is performed using general anesthesia, which means the patient is asleep during the procedure and does not feel pain. Gastric bypass can be performed as either traditional open surgery or as less invasive laparoscopy. The latter technique requires smaller incisions and generally has a shorter recovery time than the traditional technique.

Following surgery, patients are placed on a special diet that lasts for several months and progresses from liquids to pureed foods and soft foods. Eventually the patient will be allowed to eat solid foods. However, the changes to the digestive system brought on by surgery result in permanent restrictions on how much patients are able to eat and what kinds of food they can eat.

Patients may lose as much as 50 to 60 percent of their excess weight within the first two years of gastric bypass surgery. However, some patients experience complications after surgery, such as hernias or abdominal infections, some of which may be life threatening. In addition, a healthy diet, regular exercise and other physician-prescribed lifestyle changes are necessary to increase a patient’s chances of maintaining a healthy weight after the surgery.

Gastric bypass procedures are more difficult to perform than some other forms of bariatric surgery and are more likely to cause long-term nutritional deficiencies, particularly in regard to iron and calcium. This means that menstruating women are more likely to develop anemia. Osteoporosis and other bone diseases may result from calcium deficiency. Recent research also shows that nutritional deficiencies related to gastric bypass surgery may result in serious neurological conditions. To guard against nutritional deficiencies, patients may be given nutritional supplements such as a multivitamin, vitamin B-12 and minerals such as calcium and iron.

Patients who have gastric bypass surgery may also suffer from dumping syndrome, which occurs when a meal high in simple carbohydrates moves too quickly through the small intestine, leading to nausea, bloating, abdominal pain, weakness, sweating, faintness and diarrhea. Patients may also develop an infection such as peritonitis, in addition to abdominal hernia, dehydration, gallstones or stomach ulcer. Research also shows that patients may be at increased risk of developing kidney stones following gastric bypass surgery. Some of these complications may require additional surgery.

Other risks associated with bariatric surgery include:

1. Death. Patients have died as a result of these surgeries. Risk levels vary depending upon a person’s age, general health and other medical conditions. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), the risk of death from gastric bypass surgery is less than 1 percent.

2. Blood clots in the legs. These clots may form in the legs before traveling to the lungs and into the arteries found there. This can cause a pulmonary embolism, which can be fatal. Walking and wearing leg wraps can reduce this risk. Leg exercises may also be recommended.

3. Leaking from a staple line. This severe complication is usually treated with antibiotics, and some cases may require emergency surgery.

4. Narrowed opening connecting the stomach and small intestine. This complication is rare and often can be corrected by an outpatient procedure in which a tube (endoscope) is inserted through the mouth to widen the opening. In some cases, corrective surgery may be necessary.

5. Pneumonia. Patients may have a higher risk of this disease after surgery.