Tummy times(credit:
Livercake)
The duodenal switch (DS) is a modification of the BPD designed to prevent ulcers, increase the amount of gastric restriction, minimize the incidence of dumping syndrome, and reduce the severity of protein-calorie malnutrition.
The DS works through an element of gastric restriction as well as mal-absorption. Anatomically, the main difference between the DS and the BPD is the shape of the stomach – the mal-absorptive component is essentially identical to that of the BPD. Compared to the BPD, the DS leaves a much smaller stomach that creates a feeling of restriction much like that of a RYGBP. Instead of cutting the stomach horizontally and removing the lower half (such as with the BPD), the DS cuts the stomach vertically and leaves a tube of stomach that empties into a very short (2-4 cm) segment of duodenum.
The duodenum is tolerant of stomach acid and therefore is much more resistant to ulceration compared to the small intestine. Removing part of the stomach also decreases the amount of acid present. The DS involves an anastomosis between the duodenum and the intestine.
The disadvantage of transecting the duodenum is the large number of vital structures immediately adjacent to the duodenum. Several large blood vessels and the major bile duct are located here. Injury to these structures can be life-threatening.