Duodenal switch provides superior weight loss in the super-obese (BMI > or =50 kg/m2) compared with gastric bypass

Abstract

Objectives: Although weight loss following Roux-en-Y gastric bypass is acceptable in patients with preoperative body mass index (BMI) between 35 and 50 kg/m, results from several series demonstrate that failure rates approach 40% when BMI is > or =50 kg/m. Here we report the first large single institution series directly comparing weight-loss outcomes in super-obese patients following biliopancreatic diversion with duodenal switch (DS) and Roux-en-Y Gastric Bypass (RYGB).

Methods: All super-obese patients (BMI > or =50 kg/m) undergoing standardized laparoscopic and open DS and RYGB between August 2002 and October 2005 were identified from a prospective database. Two-sample t tests were used to compare weight loss, decrease in BMI, and percentage of excess body weight loss (% EBWL) after surgery. chi analysis was used to determine the rate of successful weight loss, defined as achieving at least 50% loss of excess body weight.

Results: A total of 350 super-obese patients underwent DS (n = 198) or RYGB (n = 152) with equal 30-day mortality (DS,1 of 198; RYGB, 0 of 152; P = not significant). The % EBWL at follow-up was greater for DS than RY (12 months, 64.1% vs. 55.9%; 18 months, 71. 9% vs. 62.8%; 24 months, 71.6% vs. 60.1%; 36 months, 68.9% vs. 54.9%; P < 0.05). Total weight loss and decrease in BMI were also statistically greater for the DS (data not shown). Importantly, the likelihood of successful weight loss (EBWL >50%) was significantly greater in patients following DS (12 months, 83.9% vs. 70.4%; 18 months, 90.3% vs. 75.9%; 36 months, 84.2% vs. 59.3%; P < 0.05).

Conclusions: Direct comparison of DS to RYGB demonstrates superior weight loss outcomes for DS.

FIGURE 1. Weight loss following DS is greater than RYGB. DS, duodenal switch; RY, Roux-en-Y gastric bypass. Two-sample t tests were used for comparison. *P < 0.01.

FIGURE 2. Excess body weight loss following DS is greater than RYGB. DS, duodenal switch; RY, Roux-en-Y gastric bypass. EBWL is expressed as a percentage; EBWL is calculated as: weight lost/(initial weight − ideal body weight). DS, duodenal switch; RY, Roux-en-Y gastric bypass. Two-sample t tests were used for comparison. *P < 0.01.

FIGURE 3. Comparison of body mass index (BMI) during follow-up. DS, duodenal switch; RY, Roux-en-Y gastric bypass. By 3 years after surgery, despite having an initially greater BMI, the mean BMI was significantly less in the DS group. Two-sample t tests were used for comparison. *P < 0.05.

FIGURE 4. Comparison of changes in body mass index (BMI) over time. DS, duodenal switch; RY, Roux-en-Y gastric bypass. Two-sample t tests were used for comparison. *P < 0.01.