Gallstone Removal Resulting in Resolution of a Rare Case of Bouveret Syndrome

Introduction: Bouveret syndrome is a rare variant of gallstone ileus caused by an acquired fistula via the gallbladder and either the stomach or duodenum. Fistulization occurs due to inflammation and pressure via gallstones following acute cholecystitis which may result in an ischemic tear. There are approximately 300 documented case reports over the past 50 years, as Bouveret syndrome accounts for 1%-3% of cases of gallstone ileus and affects < 0.5% of patients with gallstones. The nonspecific symptoms make diagnosis difficult, as the majority of patients present with nausea, emesis, and abdominal pain. Case Description/Methods: A 77-year-old woman with prior medical history of complicated diverticulitis with colovesical fistula status post surgical repair presented with 2-3 weeks of nausea, emesis, abdominal pain and distention, and constipation. CT abdomen and MRCP revealed a cholecystoduodenal fistula and obstructing gallstone in the duodenum. EGD findings included an obstructing stone occupying the entire lumen of the third part of the duodenum and circumferential ulcerations from presumed stone impaction sites. Conservative management with NPO, IV fluids, and NG tube decompression was started prior to transfer. ERCP revealed a 12-15 mm cholecystoduodenal fistula not amenable to endoscopic closure. A large occlusive stone measuring approximately 5-7 cm was present in the third portion of the duodenum. The stone was fragmented via snare, electrohydraulic and mechanical lithotripsy, and balloon dilation. Multiple stones measuring 8-15 mm were present in the second portion of the duodenum and were extracted with Roth net. Additional stones were moved to the stomach and broken down further with lithotripsy before removal with Roth net. The patient's symptoms resolved, and she was discharged in stable condition (Figure 1). Discussion: Bouveret syndrome typically presents as similar to a bowel obstruction in elderly femans with a history of cholelithiasis. Imaging may reveal Rigler’s triad (dilated stomach, pneumobilia, radio-opaque shadow), although, this triad is only present in 40%-50% of cases. Management includes endoscopic removal, lithotripsy, or surgical management such as gastrotomy. Mortality is increased with surgical intervention and clinicians should attempt to treat Bouveret syndrome endoscopically +/- lithotripsy if able, as mortality is already estimated at 12%-30%. Given such high mortality, this should be included on a differential in an elderly woman with a history of cholelithiasis presenting with gastrointestinal symptoms.Figure 1.: Endoscopic imaging of obstructing gallstones present in second and third portions of the duodenum.