Biliopancreatic diversion with a duodenal switch (BPD/DS), also called the “duodenal switch” or the “switch” for short, is a surgical weight loss procedure utilizing both restrictive and malabsorptive methods to achieve long term weight loss. BPD/DS improves upon the standard biliopancreatic diversion which was originally developed by Dr. Scopinaro in Italy and later modified by surgeons in the US and Canada. This complex procedure generates weight loss by restricting the amount of food that can be eaten, which then limits the amount of food the body will absorb.

General Procedure

The BPD/DS procedure involves the removal of approximately 1/2 to 2/3 of the stomach. This procedure improves on other gastric bypass procedures such as biliopancreatic diversion (BPD) and Roux-en-Y (RNY) by leaving intact more of the stomach and the entire pyloric valve, which regulates the flow of stomach contents into the small intestine. By dividing the small intestine into two parts the alimentary and biliopancreatic limbs are created. One end of the alimentary limb is connected to the now smaller stomach, while the other end remains attached to the colon. Food leaving the stomach travels through the alimentary limb, thereby avoiding the majority of the digestion that takes place in the small intestine. The biliopancreatic limb is connected to the bile duct and joins the alimentary limb to form the common channel which ends at the colon. Digestive juices then flow from the stomach and pancreas through the biliopancreatic limb and mix with food at the start of the common channel.

Compared to other gastric bypass procedures, BPD/DS is one of the most effective at creating long-term weight loss. It provides the most malabsorption of all weight loss surgeries performed today. For this reason it has been seen as controversial because it carries with it a risk of malnutrition. It’s important that a patient is monitored closely by a physician on a regular basis to ensure the proper absorption of vitamins and minerals.

Advantages of biliopancreatic diversion with a duodenal switch (BPD/DS):

• Ability to eat normal food and drink (as a result of a smaller stomach).
• Long-term weight loss, particularly for patients with a higher BMI (BMI of 55 or more).
• Reduced chance of developing an ulcer.
• The intestinal bypass portion of the surgery is partially reversible for those experiencing significant malnutrition issues.
• Virtually eliminates dumping syndrome, since the pyloric valve remains intact.

Disadvantages/risks of biliopancreatic diversion with a duodenal switch (BPD/DS):

• Chance of a hernia where the surgical incision was.
• Higher chance of chronic diarrhea and foul smelling flatulence.
• Inability to absorb enough vitamins and minerals to maintain proper nutritional levels.
• Possible surgical complications due to the complexity of the surgery (more frequent in high risk patients with sleep apnea, heart disease, etc.).
• Risk of nutritional deficiencies leading to possible anemia, protein deficiency, or metabolic bone disease.