Duodenal Switch (DS)

Not to be confused with the biliopancreatic diversion with a duodenal switch, the ”original” duodenal switch was once a procedure in its own right. The standalone Duodenal Switch procedure was originally devised by Tom R. DeMeester, M.D. to treat a condition in which the stomach and esophagus are burned by bile.

Dr. Douglas Hess of Bowling Green, Ohio, was the first surgeon to combine the DS with the Biliopancreatic Diversion (BPD) form of obesity surgery in 1988. This hybrid procedure, known as the Biliopancreatic Diversion with Duodenal Switch (or the Distal Gastric Bypass with Duodenal Switch), solves many nutritional problems associated with other forms of weight loss, and allows a magnificent eating quality when compared to other weight loss procedures.

This operation and its modifications have been widely performed for more than 35 years in Europe with excellent long-term studies and results. This operation is an effective bariatric procedure to significantly combine both restrictive and malabsorptive aspects for the goal of long-term weight loss.

The operation has two parts. The first is a ”sleeve gastrectomy”. This part of the operation has several effects and accounts for the restrictive effects (ie, restricting food intake). By removing a large portion of the stomach, the capacity to store food is markedly decreased. This gives the feeling of fullness quickly after starting a meal.

Also, the portion of the stomach that is removed produces a newly described hormone (called ”ghrelin”) that is responsible for the sensation of hunger. By removing the effects of this hormone, patients lose the sensation of hunger. The remaining stomach is the length and diameter of your index finger.

The second part of the operation is the malabsorptive portion. Most food is absorbed in the small intestine after it is broken down by bile and pancreatic juices. The purpose of bile is to dissolve fats into a form that can be absorbed by the small intestine. Pancreatic juices also dissolve fats (as well as proteins and sugars). Both bile and pancreatic juices enter the intestines at the duodenum (the first part of the small intestines). The intestines are reconnected, switching out the duodenum, where these fluids normally enter.

By connecting your intestines in such a way that food is diverted from these bilio-pancreatic juices until the very last portion, food is not fully absorbed. Instead the person will pass a lot of fats undigested and unabsorbed.

The duodenal switch operation is so named because the functional portion of the duodenum (the upper small intestine) is bypassed from digestive continuity in a reversal or "switch" technique.

The standalone DS procedure is another enhancement of the BPD (it is also referred to as ’BPD/DS’). Here again, there is a significant malabsorptive component which acts to maintain weight loss long term. The patient must be closely monitored to guard against severe nutritional deficiencies. The main difference between the BPD and the DS is that the DS keeps the pyloric valve intact. 

The most important feature of the operation is that it rearranges the small intestines, so that the food is diverted and only absorbed in the last 75-100 cm, otherwise known as the "common channel." The section of the intestines that carry the food from the small stomach does not join with the section carrying the digestive juices from the liver until very far downstream. Because of this, the amount of fat and calories that are absorbed from foods is greatly reduced. Since this surgery has such a high malabsorptive degree, to prevent deficiencies, a high-protein diet and lifelong vitamin and mineral supplementation are necessary.