Duodenal switch not necessarily better than RYGB for patients with high BMI

In the treatment of patients with a BMI of 50–60 kg/m², duodenal switch (DS) appears to result in better weight loss outcomes but also more frequent adverse events, including nutritional complications, as compared with Roux-en-Y-gastric bypass (RYGB), according to an open-label study.

Sixty patients with a BMI of 50–60 kg/m² were randomly assigned to undergo either DS or RYGB, performed laparoscopically. Of these patients, 48 (80 percent, mean age 48.0 years, 73 percent female) attended follow-up consultations, including 23 in the RYGB group and 25 in the DS group, and were included in the analysis.

After a median follow-up of 12 years, the primary outcome of BMI reduction was significantly greater in the DS group than in the RYGB group (20.3 vs 11.0 kg/m²; p<0.001).

Results for other secondary outcomes also favoured DS. These included total weight loss (33.9 percent vs 20.0 percent; p=0.001), systolic BP (–8 vs 2 mm Hg; p=0.02), HbA1c (–14 vs –4 mmol/mol; p=0.006), and total cholesterol (–46 vs –4 mg/dL; p<0.001), among others.

Bone mass decreased in both groups, with lower bone mass in the DS group at 10 years. Quality-of-life scores, assessed using the Obesity-Related Problem Scale and the 36-Item Short Form Health Survey, were similar between groups at 10 years.

However, adverse events occurred more frequently with DS than with RYGB (135 vs 97; p=0.02). Significantly more patients in the DS group had vitamin deficiencies (21 vs 11; p=0.008), including 25-hydroxyvitamin D deficiency (19 vs 9; p=0.005). Severe protein-caloric malnutrition occurred in four patients in the DS group, of whom three underwent revisional surgery.