Rare Duodenal Switch Surgery Adds 50 Pounds More Weight Loss

A rare surgery known as the duodenal switch can add 50 pounds more weight loss than gastric bypass, but it comes with complications and long-term risks for obesity patients.

The study, published in the Annals of Internal Medicine, followed 60 severely obese patients who were randomly assigned to either gastric bypass surgery or a more extensive procedure called the duodenal switch. Two years after surgery, patients had lost more 50 pounds more weight on average.

The restrictive portion of the DS surgery involves removing approximately 70% of the stomach along the greater curvature. The malabsorptive portion of the surgery reroutes a lengthy portion of the small intestine, creating two separate pathways and one common channel. The shorter of the two pathways, the digestive loop, takes food from the stomach to the channel. The much longer pathway, the biliopancreatic loop, carries bile from the liver to the common channel.

Of the 29 DS patients, 62 percent had problems like abdominal pain, vomiting, diarrhea and intestinal obstruction. And several suffered long-term malnutrition, a condition not seen before in the gastric bypass group.

“The technique is often reserved for super obese patients with a body mass index (BMI) of 50 or higher, though some surgeons perform it with less severely obese patients too,” explained Dr. Torgeir T. Sovik of Oslo University in Norway, the lead researcher on the new study.

“As DS can be associated with more adverse events, this procedure should only be performed in carefully selected patients by a dedicated bariatric team,” Sovik told Reuters Health in an email. “And a closer follow-up after surgery is required after such procedures.”

DS patients require lifelong and extensive blood tests to check for deficiencies in life critical vitamins and minerals. Without proper follow-up tests and lifetime supplementation, gastric bypass and DS patients can become ill. This care is non-optional and must continue for as long as the patient lives.