Malabsorptive Operation: Biliopancreatic Diversion with Duodenal Switch

This operation, which is the procedure of choice of 5% of people, is one of the most effective treatments in terms of weight loss. It is a very powerful tool, however, and is generally reserved for people with the most severe disease -- usually a body mass index (BMI) of 50 or more. It is an operation that separates food from digestive enzymes for 90% of the small intestine (where food is absorbed). This means that only 10% of the length of the small intestine is available to take in the nutrients from food. As a result, some nutrients pass into the large intestine, and are passed out in the stool. This reduces the calories that your body takes in, and weight is lost.

Duodenal switch includes removal of a portion of the stomach, and does provide a small amount of "restriction." One may feel a sense of "satiety" with a smaller than normal meal. Satiety is the signal that your stomach sends to your brain when it has stretched due to food. Your brain interprets this signal as a sense of "satisfaction," "fullness," or that you've "had enough." Once you have received this signal, you need to make a conscious choice that since you feel that way, that it is time to stop eating. This is a minor contribution to the weight loss.

This operation can provide feedback to you from the restriction, but also provides feedback in other ways. If you eat foods with excessive fat (which is poorly absorbed), the large intestine cannot break it down, and you may have loose stools. This is a reminder from your body that such foods are not an appropriate choice for you. Similarly, some complex carbohydrates (starches) may also not be fully absorbed. These are fermented in the large intestine and may become foul-smelling gas which is passed out the rectum. Again, this is a way for your body to tell you that such foods are not appropriate.

How Your Anatomy Is Changed
This operation is quite complex. First, 75% of the stomach bearing the majority of the acid-making portion is removed. Just after the pylorus, a muscle that controls the emptying of the stomach, the first part of the small intestine (duodenum) is divided. Two channels of small intestine are created -- one to carry food from the stomach, and one that carries digestive enzymes (made by the liver and pancreas). Close to the end of the small intestine, these two channels are connected, allowing food and digestive enzymes to mix. Because gallstones are very common after this operation, the gallbladder is also removed. A biopsy of the liver is also taken to assess the health of the liver at the time of surgery.

The Operative Procedure
This operation can be performed is done only through a large incision in our practice. Some centers are performing this operation laparoscopically, but we do not at this time. See our section about methods of operations for more information. The technical details of the two channels of the small intestine include 10% of the total length of the small intestine devoted to the area where mixing of food and enzymes occur. The remainder is distributed with 40% to carry food, and 60% to carry digestive enzymes.

Results
This operation has very good results in helping relieve obesity-related conditions. High blood pressure, high cholesterol, sleep apnea, diabetes, joint pains, and other illness can improve in a large number of patients. Since most people have obesity surgery to improve their health, this is one of the ways we measure success. In terms of weight loss, most people lose about 70% of the excess weight they carry at about one year after surgery. Over five years, most people have maintained 80-85% of their excess weight.

Nutritional Impact
Because food is poorly absorbed as a main intent of this operation, there is the potential for deficiencies of nutrients. The most serious of these is not absorbing enough protein. See our section on protein for more information. Without adequate protein, muscle wasting can occur - including wasting of our most important muscle, the heart. The liver also requires significant protein in order to do its work properly, and lack of protein can cause liver damage, or in very serious cases, even liver failure.

Other important nutrients that can be affected include the fat soluble vitamins: Vitamins A, D, E, and K. Additional water soluble forms of these vitamins must be taken 2-3 times a day FOR LIFE to prevent deficiencies. An additional multivitamin, calcium, and sometimes iron is also required.