Emergent gastric remnant volvulus in a post-OAGB patient with massive hiatal herniation: a life-threatening presentation in an asymptomatic course

One anastomosis gastric bypass (OAGB) is a widely used bariatric procedure with favorable outcomes and a relatively low complication rate. However, both early and late postoperative complications can occur, including rare but serious events such as gastric remnant volvulus, particularly in the presence of massive hiatal herniation. The altered anatomy following OAGB can make the diagnosis of such complications challenging, especially when clinical presentations are atypical or silent. We report the case of a 67-year-old woman with a history of OAGB and prior hiatal hernia repair who presented nearly 4 years postoperatively with isolated elevations in cholestatic liver enzymes but no abdominal symptoms. Imaging revealed a massive hiatal hernia containing the gastric pouch, gastrojejunal anastomosis, remnant stomach, and a portion of the pancreas, with evidence of partial gastric remnant volvulus and duodenal obstruction. The patient developed acute gastrointestinal bleeding during hospitalization, prompting urgent laparoscopic intervention. Intraoperative findings confirmed a large hiatal defect with herniation and rotation of the gastric remnant. Surgical management included reduction of herniated organs, gastrotomy for decompression, hiatal repair, and resection of the remnant stomach. The patient recovered uneventfully. This case underscores the importance of maintaining a high index of suspicion for rare but life-threatening complications such as gastric remnant volvulus in post-OAGB patients, even in the absence of classic symptoms. Timely imaging and prompt surgical intervention are essential for favorable outcomes. Ongoing, individualized follow-up and multidisciplinary care are crucial for early detection and management of late bariatric surgery complications.