One anastomosis gastric bypass versus Roux-en-Y gastric bypass for morbid obesity: a meta-analysis.

We aim to review the available literature on morbidly obese patients treated with one anastomosis gastric bypass (OAGB) or Roux-en-Y gastric bypass (RYGB) in order to compare the clinical outcomes of the two methods. A literature search was performed in PubMed, Cochrane library and Scopus, in accordance with the PRISMA guidelines. Twelve studies met the inclusion criteria (7452 patients). OAGB was associated with shorter mean operative time. The length of hospital stay was comparable between the two procedures. The incidence of leaks, marginal ulcer, dumping, bowel obstruction, revisions and mortality was similar between the two approaches. The incidence of malnutrition was increased in patients treated with OAGB, while the incidence of internal hernia and bowel obstruction was greater in the RYGB group. In addition, the percentage excess weight loss at 1, 2 and 5 years post-operatively was greater for the OAGB group. The rate of type 2 diabetes remission was greater in the OAGB group. The rate of hypertension and dyslipidemia remission was also similar between OAGB and RYGB. Randomized controlled trials, comparing RYGB to OAGB, are necessary to further assess their clinical outcomes.