EGS P23 A rare case of gallstone ileus post Roux-en-Y Gastric Bypass: Stone migration from large duodenal diverticulum

Abstract

Abstract Background Small bowel obstruction following Roux-en-Y gastric bypass is common and is mainly attributed to adhesions or internal herniation. Intraluminal formation of stones, usually in areas of stasis due to the anatomical changes post-RYGB, and migration to the distal ileum to cause acute bowel obstruction is rare. Impacted stones at the duodenal diverticulum can trigger diverticular inflammation, back pressure to the common bile duct and pancreas resulting in abdominal pain, nausea and vomiting, intermittent derangement of liver enzymes and episodes of cholangitis and pancreatitis. The impaction at the distal ileum is an emergency requiring prompt diagnosis and intervention to prevent complications. Methods This is a case report of a 56-year-old female who presented at East Surrey Hospital in February 2023 with recurrent upper abdominal pain, nausea and vomiting. She previously underwent an open cholecystectomy for cholelithiasis and cholecystoduodenal fistula (2003) and a Roux-en-Y gastric bypass (2018). Her symptoms were initially thought to be secondary to inflammation and periduodenal abscess managed with antibiotics, but as time and scans (CT, MRCP, water-soluble contrast, gastroscopy) progressed without resolution of her symptoms it became evident that she had developed mechanical bowel obstruction. We described her case and the diagnostic challenges leading to the final surgical management. Results To investigate the patient’s symptoms, her intermittently raised inflammatory markers, deranged liver enzymes and amylase a series of radiological examinations was rperformed. Initial CT scan showed an inflamed large duodenal (D3) diverticulum and fluid filled proximal duodenum. Subsequent MRCP demonstrated dilated common bile duct and intrahepatic ducts without any ductal stone. Repeat CT scan two weeks later, confirmed small bowel obstruction due to a heterogenous bolus at the ileocecal valve with resolution of the duodenal inflammation and dilatation. The patient underwent a laparoscopic extraction of a stone impacted at the ileocecal valve causing small bowel obstruction and recovered well. Conclusions Even though small bowel obstruction due to stone aggregation is uncommon post-RYGB, a high index of suspicion for the diagnosis and a low threshold for early laparoscopic intervention can prevent further serious complications. Reporting these cases in literature offers a guidance for the workup and management of these unusual scenarios amongst surgical teams and improves patients’ outcomes.