Figure 1: (A) CT abdomen and pelvis coronal section demonstrating the presence of pneumobilia, as indicated by the red arrow; (B) CT coronal section demonstrating the presence of a subtle yet possible tissue bridge between the common bile duct and duodenum, suspicious for a CDF, as indicated by the red arrow.
Endoscopic retrograde cholangiopancreatography (ERCP) was performed to further investigate and manage the fistula tract visualised on CT. A fistula was identified between the D1/D2 junction and common bile duct. Both the proximal and distal openings of the fistula tract were able to be cannulated (see Figure 2). Small volume clear pancreatic fluid was noted to emerge from the major ampulla, but no bile was seen, suggesting a chronic distal bile duct obstruction. Multiple attempts were made to cannulate the native ampulla, albeit to no avail. A fully-covered metal stent was inserted into the fistula tract for formalisation, facilitating biliary drainage. The patient tolerated the procedure well, with resolution of his symptoms and normalisation of his biochemistry.