Choledochoduodenal fistulas (CDFs) - between the common bile duct and the duodenum - represent the rarest type of abnormal enterobiliary communications. The most common type is the cholecystoduodenal fistula (70% of all EFs) followed by cholecystogastric fistula (0-13.3%), cholecystocolic fistula (0-10.9%) and cholecystoileal (0-2.5%) [1]. Possible etiologies may include cholelithiasis, peptic ulcer disease and trauma. Diagnosis is typically made on endoscopic retrograde cholangiopancreatography (ERCP) [2]. We present a case of a 73-year-old female with choledocholithiasis.

Case Presentation:

A 73-year-old female with a medical history of arterial hypertension and smoking, presented to our department with mild abdominal pain and jaundice. Clinical examination revealed mild epigastric tenderness and scleral jaundice; otherwise, the examination was unremarkable. Her labs on presentation were notable for a high level of C-reactive protein (CRP). Her liver function panel was abnormal with a total bilirubin of 2.6 mg/dl, direct bilirubin 1.4 mg/dl, AST 138 U/L and ALT 144 U/L, alkaline phosphatase 446 U/L and γ-GT 640 U/L. INR and albumin were normal. A magnetic retrograde cholangiopancreatography (MRCP) had been conducted a few months prior to the visit, had demonstrated multiple gallstones within the intra- and extrahepatic biliary tree, accompanied by common bile duct dilatation. No biliary strictures were identified. The patient subsequently underwent endoscopic intervention. ERCP revealed the presence of a choledochoduodenal fistula containing a huge impacted stone (diameter greater than 45mm) within the fistula tract. A wide sphincterotomy and sphincteroplasty were performed and biliary double pigtail stent was placed, uneventfully, achieving satisfactory drainage. The patient was discharged the next day, while on antibiotic therapy, after demonstrable improvement in laboratory values and remained asymptomatic with spyglass cholangioscopy lithotripsy pending.

Discussion:

Choledochoduodenal fistulas are extremely rear, pose a diagnostic challenge and are found mainly incidentally during endoscopy, which remains fundamental for their identification and direct visualization. Therapeutic decision making is contingent upon the underlying etiology, the presence of concomitant complications and overall symptom burden [3]. Our patient supposedly developed the fistula as a result of longstanding choledocholithiasis. In this case, it appears that cannulation of the common bile duct with subsequent stent placement contributed to effective biliary decompression, improvement of patients’ symptoms and lowering the risk of recurrent biliary events. Management strategies of CDFs are not standardized, depend on etiology and symptom severity, with endoscopic intervention being effective in many cases. Larger fistulas may require surgical management, especially when other treatment strategies fail. Each case should be individualized based on the underlying etiology and the patients’ clinical profile.