S5236 Bouveret’s Syndrome: A Rare Form of Gallstone Ileus

Introduction: Bouveret’s syndrome is a rare complication of cholelithiasis, in which a large gallstone erodes into the proximal duodenum, creating a cholecystoduodenal fistula, and lodging itself immediately distal to the pyloric channel leading to a gastric outlet obstruction (GOO). It is most common in women with a history of gallstones, and typically presents with diffuse abdominal pain, nausea, and vomiting. A radio-opaque obstruction of the proximal duodenum on imaging raises suspicion for Bouveret's syndrome. Treatment options include endoscopic, laparoscopic, and open surgical intervention. Case Description: A 77-year-old woman presented with a 6-week history of nausea, vomiting, and abdominal pain. Labs were notable only for elevated lipase (2500 U/L) with all other liver function tests within normal limits. Computed tomography (CT) of the abdomen showed a large mass in the proximal duodenum with evidence of pancreatitis and gastritis. Magnetic resonance cholangiopancreatography confirmed a 3 cm gallstone in the duodenal bulb with cholecystoduodenal fistula, pneumobilia and evidence of complete GOO. A nasogastric tube was placed, and multiple liters of gastric fluid were suctioned. The patient underwent esophagogastroduodenoscopy (EGD) with endoscopic retrograde cholangiopancreatography for further evaluation with plan for bile duct stenting to aid with decompression in anticipation of need for surgical intervention with exploratory laparotomy. During EGD, meticulous fragmentation with electrohydraulic lithotripsy (EHL) was performed using 15 EHL probes. The stone was found to have 3 separate layers: an outer layer with green/black deposit, a yellow cholesterol layer, and a very hard crystal-like core. After 3 hours of EHL, the stone was successfully broken up, with follow up CT confirming the presence of the fragments distally in the ascending colon. The patient recovered without complications and was discharged home a few days later without the need for surgical intervention. Discussion: Bouveret’s syndrome is a rare cause of GOO characterized by cholecystoduodenal fistula complicated by large gallstone impaction within the enteric tract. There are currently no standardized guidelines for the management of Bouveret’s syndrome. Traditional management includes laparoscopic or open surgical stone removal, with individualized decision for subsequent cholecystoduodenal fistula repair and/or cholecystectomy. Advanced EGD techniques including mechanical removal and EHL allow patients to avoid the morbid risks associated with surgery.