Background: Obesity is a rising threat to public health. The relative increase in the incidence of morbid obesity is most pronounced in the most severely obese. Roux-en-Y gastric bypass (RYGB) results in inferior weight loss in this group. Therefore, we have offered biliopancreatic diversion with duodenal switch (BPD/DS) as an alternative for this patient category. Our objective was to compare BPD/DS and RYGB in the surgical treatment of morbid obesity in patients with a body mass index (BMI) >48 kg/m(2). The setting was a university hospital in Sweden.

Methods: In a controlled trial (registration number ISRCTN10940791), 47 patients (25 men, BMI 54.5 ± 6.1 kg/m(2)) were randomized to RYGB (n = 23) or BPD/DS (n = 24). Biochemical data were collected preoperatively and 1 and 3 years postoperatively. A questionnaire addressing weight, general satisfaction, and gastrointestinal symptoms was distributed a median of 4 years postoperatively.

Results: Both procedures were safe. The duration of surgery and postoperative morphine consumption were greater after BPD/DS than after RYGB (157 versus 117 min and 140 versus 93 mg, respectively). BPD/DS resulted in greater weight loss than RYGB (-23.2 ± 4.9 versus -16.2 ± 6.9 BMI units or 80% ± 15% versus 51% ± 23% excess BMI loss, P <.001). BPD/DS yielded lower glucose and glycated hemoglobin levels at 3 years. More patients listed troublesome diarrhea and malodorous flatus in the questionnaire after BPD/DS, but no significant difference was seen (P = .078 and P = .073, respectively).

Conclusions: BPD/DS produced superior weight results and lower glycated hemoglobin levels compared with RYGB in patients with a BMI >48 kg/m(2). Both operations yield high satisfaction rates. However, diarrhea tended to be more common after BPD/DS.