What is biliopancreatic diversion (BPD)?

BPD is a surgery for obesity in which a large part of the lower stomach is removed and the small part of stomach that is left is connected directly to the last part of the small intestine (jejunum).  After a BPD, the stomach size is usually larger than with gastric bypass. Unlike in gastric bypass where the excluded stomach is left in place, the BPD involves a removal of a variable volume of the organ. Further, the bypass of the small intestine is much longer than in a standard roux-en-y gastric bypass, leaving only a short segment of small bowel exposed to the mix of nutrients and bile. This significantly reduces absortion of nutrients and contributes to the profound weight loss effect of the procedure. On the other hand, it is associated with a greater risk of nutritional side effects. At NewYork-Prebyterian the procedure is performed in its technical variant called BPD-Duodenal Switch, to reduce some of the potential side effect of the classic BPD.

A biliopancreatic diversion changes the normal process of digestion by making the stomach smaller. It allows food to bypass part of the small intestine so that you absorb fewer calories. Because of the risks, this surgery is only done in people who are severely obese and who haven't been able to lose weight any other way. Severe obesity means that you have a BMI (body mass index) of 50 or higher.

After surgery, you will feel full more quickly than when your stomach was its original size. This reduces the amount of food you will want to eat. Bypassing part of the intestine also means that you will absorb fewer calories. This leads to weight loss. But your best chance of keeping weight off after surgery is by adopting healthy habits, such as healthy eating and regular physical activity.

There are two biliopancreatic diversion surgeries: a biliopancreatic diversion and a biliopancreatic diversion with duodenal switch. Most surgeons will not perform duodenal switch surgery unless you are severely obese (BMI of 50 or higher) and your weight is causing serious health problems.

• In a biliopancreatic diversion, part of the stomach is removed. The remaining part of the stomach is connected to the lower portion of the small intestine. This is a high-risk surgery that can cause long-term health problems, because your body has a harder time absorbing food and nutrients. People who have this surgery must take vitamin and mineral supplements for the rest of their lives, which can be expensive.
•  In a biliopancreatic diversion with duodenal switch, a different part of the stomach is removed, which allows the surgeon to leave the pylorus, the valve that controls food drainage from the stomach, to be left intact. This is a high-risk surgery that can cause long-term health problems, because your body has a harder time absorbing food and nutrients. People who have this surgery must take vitamin and mineral supplements for the rest of their lives, which can be expensive. Another name for this surgery is duodenal switch.

These procedures can be done by making a large cut in the belly (an open procedure) or by making a small cut and using small tools and a camera to guide the surgery (laparoscopy).