The effect of stoma size on the mid-term weight loss outcome of one anastomosis gastric bypass (OAGB): a single-blinded prospective randomized trial.

Background: One anastomosis gastric bypass (OAGB) is gaining wide spread acceptance among bariatric surgeons all over the world because of its technical simplicity and documented efficacy. However, the relation between stoma size in OAGB and magnitude of weight loss has not been addressed.

Objectives: To evaluate the effect of stoma size on the mid-term weight loss outcome for patients with obesity after OAGB.

Setting: University Hospital.

Materials And Methods: This is a single-blinded prospectively randomized trial. From March 2014 to September 2016, 83 patients, eligible for bariatric surgery, were included in the study. OAGB was carried out with the same technical steps, except for the size of the gastrojejunostomy (GJ). Patients were randomly allocated into two equal groups; narrow GJ group (30 mm) and wide GJ group (45 mm). The percentage of total weight loss (%TWL) and the percentage of excess weight loss (%EWL) were recorded at 6, 12 and 24 months after procedure.

Results: At 6 months follow-up, patients with 30 mm GJ had better %EWL (53.3) and %TWL (23.4) than other patients with 45 mm GJ (42.6 and 18.2 respectively). However, at 12 and 24 months the %TWL and %EWL difference between the two groups have disappeared.

Conclusion: Patients with narrower stoma size (30 mm) of OAGB tend initially to lose more weight than patients with wider stoma (45 mm). However, this difference disappears at mid-term follow-up after 2 years.