Similar weight-loss outcomes with one anastomosis, Roux-en-Y gastric bypass procedures
medwireNews: Findings from the YOMEGA trial indicate that the one anastomosis gastric bypass (OAGB) procedure is noninferior to standard Roux-en-Y gastric bypass (RYGB) in terms of weight loss and metabolic outcomes.
However, patients undergoing OAGB have a higher risk for nutritional and inflammatory adverse events, Maud Robert (Hôpital Edouard Herriot, Lyon, France) and colleagues report in The Lancet.
The trial included 234 obese individuals from nine French obesity centers with a BMI of at least 40 kg/m2 or at least 35 kg/m2 with one comorbidity (average 43.9 kg/m²) who were randomly assigned to undergo OAGB – a new bypass procedure involving a single gastrojejunal anastomosis between a long gastric pouch and a jejunal omega loop – or to undergo standard RYGB.
It is believed that OAGB may have “the advantage of being less technically demanding and potentially less morbid,” explain Robert and co-investigators.
Two years after surgery, the 117 participants who underwent OAGB had an average excess BMI loss of 87.9%, while the 117 patients in the RYGB group had a comparable loss of 85.8%, indicating noninferiority of the newer procedure. Excess BMI loss was defined as the percentage of BMI over 25 kg/m2 lost over the 2 years.
The average total bodyweight loss at the 2-year follow-up was also similar among the OAGB and RYGB groups (37.1 vs 35.4%), and the median length of hospital stay was 5 days in both groups. As expected, OAGB was associated with a significantly shorter average time spent in surgery, at 85 minutes compared with 111 minutes for RYGB.
The researchers also analyzed the metabolic effects of weight-loss surgery in a subgroup of 58 participants who had type 2 diabetes at baseline, finding that those undergoing OAGB had a significantly greater average reduction in glycated hemoglobin levels at 2 years than patients in the RYGB group, at 1.2% versus 0.6%. A total of 60% and 38% of patients in the OAGB and RYBG groups, respectively, experienced complete remission of type 2 diabetes by the 2-year follow-up, but the difference between groups was not statistically significant.
Robert et al report that patients who underwent OAGB experienced almost twice as many overall and surgery-associated serious adverse events (AEs) over 2 years than those in the RYGB group, with such events occurring in a respective 67 versus 38 patients and 42 versus 24 patients. Of the serious AEs associated with surgery, nine were nutritional complications – including vitamin deficiency, malnutrition, anemia, and iron deficiency – in the OAGB group, while none of these events occurred in the RYGB group.
Patients who underwent OAGB were also significantly more likely than those who underwent RYGB to experience diarrhea in the first 3 months after surgery (26.0 vs 3.2%), and the degree of steatorrhea was significantly greater in the OAGB group (11 vs 7 g lipid/100 g stools).
Writing in an accompanying comment, Sten Madsbad and Jens Holst, both from the University of Copenhagen in Denmark, say that “the greatest value of this study is that it raises awareness regarding nutritional and inflammatory complications associated with OAGB.”
They note that “the length of the biliopancreatic limb used for OAGB was 200 cm (within which protein and lipid digestion is pushed distally), which might underlie the nutritional problems,” and suggest that “[a] shorter limb (150–180 cm), frequently used nowadays, might decrease diarrhoea and nutritional problems, although this theory would need to be assessed by direct comparison.”
The commentators stress that “even if the weight loss and anti-diabetic actions of a new procedure are attractive, no guarantee exists that its long-term safety profile is the same,” and therefore “strict follow-up after bariatric surgery is important after new procedures, as well as old procedures.”
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