Endoscopic Management of Choledochoduodenal Fistula Presenting as Pneumobilia

Abstract

Biliary-enteric fistulas are uncommon and often arise spontaneously due to gallstones, peptic ulcer disease, malignancy, or trauma. Diagnosis is typically made on endoscopic retrograde cholangiography (ERCP). Radiographic findings typically demonstrate pneumobilia, or air within the biliary tree. Only 8.6% of biliary-enteric fistulas are of the choledochoduodenal type. These fistulas present a formidable diagnostic and management challenge for physicians due to the infrequency with which they are encountered and their non-specific presentation. Here, we present a case of a choledochoduodenal fistula discovered in a young male. A 28-year-old male with a history of recurrent hepatic abscesses presented with intermittent and sharp epigastric abdominal pain that started the prior night. His abdominal pain was associated with non-bloody, non-bilious emesis. The patient had a history of recurrent hepatic abscesses that were treated with IR drainage and antibiotics. His labs on presentation were notable for a WBC count of 11.5 with 89% neutrophils. His liver function panel was abnormal with a total bilirubin of 5.5, direct bilirubin 2.9, AST 154, and ALT 252. Alkaline phosphatase, INR, and albumin were normal. Hepatitis panel, tuberculosis, and HIV testing were negative. An abdominal CT scan and MRCP demonstrated high attenuation in the right lobe of the liver suspicious for neoplasm, enlargement of the biliary ducts with extensive pneumobilia, and no definite evidence of choledocholithiasis. A triple phase CT showed evidence of liver cirrhosis and intrahepatic biliary ductal dilatation with no apparent focal hepatic masses. The patient subsequently underwent endoscopic intervention (Figure 1). EUS demonstrated abnormal echogenicity in the left and right lobes of the liver. ERCP confirmed the presence of a choledochoduodenal fistula containing a gallstone within the fistula tract. The patient was treated with antibiotics and successful placement of a stent across the fistula site. Biopsy of the common bile duct stricture showed no malignancy. Biopsies of the right and left lobes of the liver was negative for malignancy and showed acute and chronic inflammation with evidence of fibrosis. Recent case reports have described the use of the over-the-scope-clip system to endoscopically close choledochoduodenal fistulae. The purpose of this case is to increase awareness of this unusual clinical scenario and discuss the current treatment modalities available.Figure: Upper endoscopy identifying diffuse mild inflammation in the gastric fundus, gastric body, and gastric antrum. A large fistula was found between the common bile duct and duodenal bulb (choledochoduodenal fistula). There is a gallstone sitting within the fistula tract. Many small superficial ulcers are seen in the duodenum.