Bariatric Journal

Duodenal Switch Complications

The field of bariatric surgery has grown significantly in the last three decades with many surgical procedures abandoned while the few that have demonstrated a high level of effectiveness and safety are now being used to induce weight loss in obese people who have failed to lose weight through non-surgical methods. Among these proven surgical procedures is a duodenal switch, popularly referred to as biliopancreatic diversion with duodenal switch (BPD-DS)”. However, it is not without its complications. In fact, due to duodenal switch complications, the procedure is often reserved for morbid/super obese clients or as a revision surgery after failure of other surgical weight loss procedures.

To reduce the stomach capacity, a gastric sleeve surgery is done followed simultaneously by the malabsorptive component involving an alteration in the anatomy of the small intestine to delay contact of food particles with bile and the pancreatic enzymes till the distal part of the small intestine. The overall effect is a limitation of calorie intake and reduction in nutrient absorption. Most surgeons will do a prophylactic cholecystectomy (surgical removal of the gallbladder) to prevent the formation of gallstone.

How much of complications should be expected after the duodenal switch?

This procedure is adjudged to be the most complex of all bariatric surgeries that are currently being used as treatments for obesity. The complexity and numerous complications result from the combination of both restrictive and malabsorptive components, with each having its complications. Hence, morbidity and mortality are relatively high.

The complications of the duodenal switch can, therefore, be categorized into those that result from gastric sleeve and complications from the malabsorptive component. They are as shown in the table below.

Complications from Restrictive Component (Gastric Sleeve Component)

Complications from malabsorptive component

Leakage from staple line

Leakage from the anastomotic site

Bleeding from staple line

Bleeding from the anastomotic site

Gastro-esophageal reflux disease

Stricture around the anastomotic site

Intra-abdominal abscess

Intestinal obstructions



Hair loss

Nutritional deficiencies


Pulmonary embolism



Leakage can complicate both the restrictive and malabsorptive components of the surgery either from the staple line along the line of stomach resection or from the point of anastomosis of the intestine. Abdominal pain, abdominal distension, fever, increased pulse and respiratory rate, and shock are the manifestations of peritonitis following anastomotic or staple line leakage.
The stable line may also bleed. This may either be into the intra-abdominal cavity (extra-luminal) or the lumen of the intestine. While the former will present with peritonitis, patients with the latter may vomit blood or pass dark shining stool. Rarely, injury to intra-abdominal organs such as liver and spleen may be the source of extra-luminal bleeding.

Malabsorption is the primary cause of nutritional deficiency after duodenal switch although reduced intake from poor appetite may also contribute and nutritional supplement is required post-surgery. Protein-energy malnutrition and lack in micronutrients such as iron, calcium, zinc, folate, vitamins B1, A, D, E and K with their clinical manifestations are not uncommon after duodenal switch. Examples include hair loss from zinc deficiency, anemia from iron and folate deficiency, osteomalacia from vitamin D and calcium deficiencies. Malabsorption of fat will result in passage of pale, bulky and foul-smelling stool (steatorrhea).

Although most obese people have symptoms of heartburn especially when they lie supine, due to reflux of acidic stomach contents into the lower part of the esophagus, worsening of these symptoms, have been found to occur after gastric sleeve surgery (a component of the duodenal switch). Patients have also been seen to develop heartburn after duodenal switch despite not having it before the surgery.

Internal hernias leading to intestinal obstruction are not uncommon after duodenal switch. The alteration of the small intestinal anatomy creates potential spaces where intestinal loops may herniate. Rarely, postoperative intestinal adhesion may be the underlying cause. These patients will present with abdominal pain and distension, vomiting, constipation, and hypotension.

An abnormal narrowing of the intestine (stricture) at the sites of anastomosis or along the lesser curvature of the stomach (incisura angularis) is another complication of duodenal switch. Abdominal pain, nausea, and vomiting with difficulty with swallowing are the typical symptoms. Other complications of the duodenal switch are wound infection and halitosis

To sum up, the duodenal switch is an efficient bariatric procedure which is often reserved for morbidly obese patients. It comes with a lot of complications due to its complexity. Nevertheless, with early identification, most of the difficulties can be managed safely.

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