In recent years, better clinical understanding of procedures combining restrictive and malabsorptive approaches has increased the choices of effective weight loss surgery for thousands of patients. By adding malabsorption, food is delayed in mixing with bile and pancreatic juices that aid in the absorption of nutrients. The result is an early sense of fullness, combined with a sense of satisfaction that reduces the desire to eat.

 

Gastric Bypass Roux-en-Y (RYGBP)

In this procedure, stapling creates a small (15 to 20cc) stomach pouch. The remainder of the stomach is not removed, but is completely stapled shut and divided from the stomach pouch. The outlet from this newly formed pouch empties directly into the lower portion of the jejunum, thus bypassing calorie absorption. This is done by dividing the small intestine just beyond the duodenum for the purpose of bringing it up and constructing a connection with the newly formed stomach pouch. The other end is connected into the side of the Roux limb of the intestine creating the "Y" shape that gives the technique its name. The length of either segment of the intestine can be increased to produce lower or higher levels of malabsorption.

Click to view an interactive animation of the gatric bypass.

Advantages

One year after surgery, weight loss can average 77% of excess body weight.(6)

Studies show that after 10 to 14 years, 50-60% of excess body weight loss has been maintained by some patients.(6)

A study in 2000 of 500 patients showed that 96% of certain associated health conditions were improved or resolved.(6)

Risks

Because the duodenum is bypassed, poor absorption of iron and calcium can result in the lowering of total body iron and a predisposition to iron deficiency anemia. This is a particular concern for patients who experience chronic blood loss during excessive menstrual flow or bleeding hemorrhoids. Women, already at risk for osteoporosis that can occur after menopause, should be aware of the potential for heightened bone calcium loss.

Bypassing the duodenum has caused metabolic bone disease in some patients, resulting in bone pain, loss of height, humped back and fractures of the ribs and hip bones. All of the deficiencies mentioned above, however, can be managed through proper diet and vitamin supplements.

A chronic anemia due to Vitamin B12 deficiency may occur. The problem can usually be managed with Vitamin B12 pills or injections.

A condition known as "dumping syndrome" can occur as the result of rapid emptying of stomach contents into the small intestine. This is sometimes triggered when too much sugar or large amounts of food are consumed. While generally not considered to be a serious risk to your health, the results can be extremely unpleasant and can include nausea, weakness, sweating, faintness and, on occasion, diarrhea after eating. Some patients are unable to eat any form of sweets after surgery.

In some cases, the effectiveness of the procedure may be reduced if the stomach pouch is stretched and/or if it is initially left larger than 15-30cc.

The bypassed portion of the stomach, duodenum and segments of the small intestine cannot be easily visualized using X-ray or endoscopy if problems such as ulcers, bleeding or malignancy should occur.

 

Biliopancreatic diversion

While these operations also reduce the size of the stomach, the stomach pouch created is much larger than with other procedures. The goal is to restrict the amount of food consumed and alter the normal digestive process, but to a much greater degree. The anatomy of the small intestine is changed to divert the bile and pancreatic juices so they meet the ingested food closer to the middle or the end of the small intestine. With the three approaches discussed below, absorption of nutrients and calories is also reduced, but to a much greater degree than with previously discussed procedures. Each of the three differs in how and when the digestive juices (i.e., bile) come into contact with the food.

Since food bypasses the duodenum, all the risk considerations discussed in the gastric bypass section regarding the malabsorption of some minerals and vitamins also apply to these techniques, only to a greater degree.

Biliopancreatic Diversion (BPD)

BPD removes approximately 3/4 of the stomach to produce both restriction of food intake and reduction of acid output. Leaving enough upper stomach is important to maintain proper nutrition. The small intestine is then divided with one end attached to the stomach pouch to create what is called an "alimentary limb." All the food moves through this segment, however, not much is absorbed. The bile and pancreatic juices move through the "biliopancreatic limb," which is connected to the side of the intestine close to the end. This supplies digestive juices in the section of the intestine now called the "common limb." The surgeon is able to vary the length of the common limb to regulate the amount of absorption of protein, fat and fat-soluble vitamins.

Biliopancreatic Diversion with “Duodenal Switch”

This procedure is a variation of BPD in which stomach removal is restricted to the outer margin, leaving a sleeve of stomach with the pylorus and the beginning of the duodenum at its end. The duodenum, the first portion of the small intestine, is divided so that pancreatic and bile drainage is bypassed. The near end of the "alimentary limb" is then attached to the beginning of the duodenum, while the "common limb" is created in the same way as described above.

Click to view an interactive animation of the BPD with "Duodenal Switch".

Advantages

These operations often result in a high degree of patient satisfaction because patients are able to eat larger meals than with a purely restrictive or standard Roux-en-Y gastric bypass procedure.

These procedures can produce the greatest excess weight loss because they provide the highest levels of malabsorption.

In one study of 125 patients, excess weight loss of 74% at one year, 78% at two years, 81% at three years, 84% at four years, and 91% at five years was achieved(6).

Long-term maintenance of excess body weight loss can be successful if the patient adapts and adheres to a straightforward dietary, supplement, exercise and behavioral regimen.

Risks

For all malabsorption procedures there is a period of intestinal adaptation when bowel movements can be very liquid and frequent. This condition may lessen over time, but may be a permanent lifelong occurrence.

Abdominal bloating and malodorous stool or gas may occur.

Close lifelong monitoring for protein malnutrition, anemia and bone disease is recommended. As well, lifelong vitamin supplementing is required. It has been generally observed that if eating and vitamin supplement instructions are not rigorously followed, at least 25% of patients will develop problems that require treatment.

Changes to the intestinal structure can result in the increased risk of gallstone formation and the need for removal of the gallbladder.

Re-routing of bile, pancreatic and other digestive juices beyond the stomach can cause intestinal irritation and ulcers.