Ring-Augmented versus Non-Ring-Augmented One-Anastomosis Gastric Bypass as Revisional Surgery after Sleeve Gastrectomy: a Comparative Cohort Study

BACKGROUND: Sleeve gastrectomy (SG) is the most frequently performed metabolic and bariatric surgery (MBS) worldwide, but long-term suboptimal weight loss (SOWL) or recurrent weight gain (RWG) affects up to one third of patients and often necessitates revisional procedures. One-anastomosis gastric bypass (OAGB) is an effective revision, yet pouch dilation and late RWG remain concerns. Ring augmentation (RA) has been proposed to enhance restriction and sustain weight loss, but evidence in the revisional OAGB setting is limited. METHODS: This retrospective comparative cohort study analyzed 94 adults who underwent revisional OAGB after SG at a high-volume tertiary MBS center. Patients were grouped into two categories: Ring Augmented OAGB (RaOAGB) (n = 45) and Non-Ring Augmented OAGB (NRa-OAGB) (n = 49). The primary outcomes were percentage excess weight loss (%EWL), percentage total weight loss (%TWL), and change in body mass index (BMI) at 3, 6, and 12 months. Secondary outcomes included improvement of obesity-related conditions, metabolic parameters (lipid profile, HbA1c), nutritional markers, operative time, hospital stay, and early/late complications. RESULTS: Both groups achieved significant weight reduction at 12 months (p < 0.001 within groups). RaOAGB yielded greater BMI reduction (27.6 vs. 32.2 kg/m²), %EWL (81.7% vs. 61.3%), and %TWL (31.5% vs. 24.2%) compared with NRa-OAGB (all p < 0.001). Lipid profiles improved in both groups; LDL decreased, and total cholesterol equalized by 12 months. Glycemic control changes were modest and similar between cohorts. Operative time, length of stay, and early postoperative complications were comparable. Ring-related adverse events were infrequent (food intolerance 6.7% vs. 4.1%; no erosions were observed; one patient (2.2%) required ring removal at 10 months due to persistent vomiting and food intolerance). CONCLUSIONS: RaOAGB is a safe and effective revisional option for RWG and SOWL after SG, achieving significantly greater 1-year weight loss than standard OAGB, with uncommon ring-related adverse events, including one ring removal. These findings support the role of mechanical reinforcement to enhance the durability of revisional bypass but warrant confirmation through long-term, multicenter randomized trials.