Internal Hernia After One Anastomosis Gastric Bypass (OAGB). Lessons Learned from a Retrospective Series of 3368 Consecutive Patients Undergoing OAGB with a Biliopancreatic Limb of 150 cm

Background: Internal hernia (IH) represents a relatively common and well-known complication after Roux-en-Y gastric bypass. IH after one anastomosis gastric bypass (OAGB) is less frequent and rarely reported in the literature. This study presents a series of IH after OAGB observed in a high-volume bariatric center. Methods: Data of patients who underwent OAGB with an afferent limb of 150 cm between May 2010 and September 2019 were prospectively collected and retrospectively analyzed. Data of patients undergoing surgery for IH during follow-up were collected and analyzed. Results: Ninety-six patients out of 3368 with a history of OAGB had intestinal incarceration in the Petersen’s orifice (2.8%). Specificity and sensitivity of computed tomography scans in the diagnosis of IH were 59% and 76%, respectively. The mean timeframe between OAGB and surgery for IH was 21.9±18.3 months. Mean body mass index at the time of IH surgery was 24.7 ± 3.6. Surgery was completed laparoscopically in 96.8% of cases. Nine patients (9.3%) had signs of bowel hypovascularization. In all patients, the herniated bowel was repositioned, and the Petersen’s orifice was closed, without the need for bowel resection. Mean hospital stay was 1.9 ± 4.8 days. The postoperative morbidity rate was 8.3%. Long-term IH relapse was observed in 14 patients; signs of bowel hypovascularization due to incarceration in a small orifice was observed in eight of these patients (57%). Conclusions: Incidence of IH after OAGB is 2.8%. IH is associated with a low rate of bowel ischemia and the need for intestinal resection.