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Patient Selection in One Anastomosis/Mini Gastric Bypass—an Expert Modified Delphi Consensus

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One anastomosis/mini gastric bypass (OAGB/MGB) is up to date the third most performed obesity and metabolic procedure worldwide, which recently has been endorsed by ASMBS. The main criticisms are the risk of bile reflux, esophageal cancer, and malnutrition. Although IFSO has recognized this procedure, guidance is needed regarding selection criteria. To give clinicians a daily support in performing the right patient selection in OAGB/MGB, the aim of this paper is to generate clinical guidelines based on an expert modified Delphi consensus.


A committee of 57 recognized bariatric surgeons from 24 countries created 69 statements. Modified Delphi consensus voting was performed in two rounds. An agreement/disagreement among ≥ 70.0% of the experts was considered to indicate a consensus.


Consensus was achieved for 56 statements. Remarkably, ≥ 90.0% of the experts felt that OAGB/MGB is an acceptable and suitable option “in patients with Body mass index (BMI) > 70, BMI > 60, BMI > 50 kg/m2 as a one-stage procedure,” “as the second stage of a two-stage bariatric surgery after Sleeve Gastrectomy for BMI > 50 kg/m2 (instead of BPD/DS),” and “in patients with weight regain after restrictive procedures. No consensus was reached on the statement that OAGB/MGB is a suitable option in case of resistant Helicobacter pylori. This is likely as there is a concern that this procedure is associated with reflux and its related long-term complications including risk of cancer in the esophagus or stomach. Also no consensus reached on OAGB/MGB as conversional surgery in patients with GERD after restrictive procedures. Consensus for disagreement was predominantly achieved “in case of intestinal metaplasia of the stomach” (74.55%), “in patients with severe Gastro Esophageal Reflux Disease (GERD)(C,D)” (75.44%), “in patients with Barrett’s metaplasia” (89.29%), and “in documented insulinoma” (89.47%).


Patient selection in OAGB/MGB is still a point of discussion among experts. There was consensus that OAGB/MGB is a suitable option in elderly patients, patients with low BMI (30–35 kg/m2) with associated metabolic problems, and patients with BMIs more than 50 kg/m2 as one-stage procedure. OAGB/MGB can also be a safe procedure in vegetarian and vegan patients. Although OAGB/MGB can be a suitable procedure in patients with large hiatal hernia with concurrent hiatal hernia, it should not be offered to patients with grade C or D esophagitis or Barrett’s metaplasia.

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Correspondence to Maurizio De Luca.

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Key Points

• OAGB/MGB is a suitable option in elderly patients.

• OAGB/MGB is a suitable option for patients with low BMI (30–35 kg/m2) with associated metabolic problems.

• OAGB/MGB is a suitable option in patients with BMIs more than 50 kg/m2 as one-stage procedure. OAGB/MGB can be a suitable procedure in patients with large/giant hiatal hernia with concurrent hiatal hernia repair.

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Kermansaravi, M., Parmar, C., Chiappetta, S. et al. Patient Selection in One Anastomosis/Mini Gastric Bypass—an Expert Modified Delphi Consensus. OBES SURG 32, 2512–2524 (2022).

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