The most effective surgical procedure for extreme obesity should usually be avoided

Based on five-year follow-up of patients in a randomized clinical trial, researchers have concluded that gastric bypass is the preferred treatment for extreme obesity despite the fact that it is not as effective in reducing body weight as the so-called duodenal switch.

The outcomes, which appear in the current issue of JAMA Surgery, show that duodenal switch leads to substantially better weight reduction. But at the same time, the method is associated with a higher risk of complications.

"There has not been any consensus about the recommended surgical procedure for patients with BMI greater than 50 who have extreme obesity," says Torsten Olbers, Associate Professor of Surgery at Sahlgrenska Academy, University of Gothenburg, and senior consultant surgeon.

The study was conducted as a collaborative effort between the Sahlgernska Academy, Sahlgrenska University Hospital and Oslo University Hospital. Sixty patients with extreme obesity who weighed an average of 353 pounds were randomly assigned to receive one of the two procedures. At five-year follow-up, those who had undergone duodenal switch lost an average of 146 pounds, as opposed to 90 pounds among those who had received gastric bypass surgery. The improvement in blood lipid and blood glucose levels was also more pronounced.

Nevertheless, duodenal switch was more likely to cause adverse effects. These patients were more prone to develop diarrhea and other gastrointestinal ailments. A number of patients were hospitalized for malnutrition, while some required new operations to address problems occasioned by the original surgery.

"Despite the greater efficacy of duodenal switch when it comes to weight reduction, our findings suggest that it should be used with caution, given the higher percentage of long-term adverse effects," Dr. Olbers says.

The two groups showed similar improvement in terms of remission of type 2 diabetes, risk factors for cardiovascular disease and perceived quality of life.

The article Five-Year Outcomes after Laparoscopic Gastric Bypass and Laparoscopic Duodenal Switch in Patients with Body Mass Index of 50 to 60: A Randomized Clinical Trial was published in JAMA Surgery.

Link to article:

Duodenal switch involves removing a large part of the stomach and creating two separate tracts of the small intestine and a short common limb. The body has considerably less time to absorb nutrients, especially fat.

Gastric bypass involves disconnecting the stomach such that food essentially goes directly from the esophagus to the small intestine. The primary mechanism is modification of the signals that control hunger and satiety.

Approximately 8,000 Swedes undergo bariatric procedures every year, the great majority of which are gastric bypass. Some hundred duodenal switch procedures are performed.

Torsten Olbers, Associate Professor, Sahlgrenska Academy, University of Gothenburg

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Krister Svahn

Sahlgrenska Academy, University of Gothenburg
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The Sahlgrenska Academy is the faculty of health sciences at the University of Gothenburg. Education and research are conducted within the fields of pharmacy, medicine, odontology and health care sciences. About 4,000 undergraduate students and 1,200 postgraduate students are enrolled at Sahlgrenska Academy. Around 1,400 people work at the Sahlgrenska Academy, 850 of them are researchers and/or teachers. 2013 Sahlgrenska Academy had a turnover of 2,4 billion SEK.




There has not been any consensus about the recommended surgical procedure.
Torsten Olbers, researcher at the Sahlgrenska Academy