Pneumobilia and Hepatic Abscess Secondary to Polymicrobial Infection of the Biliary Tree

A 76-year-old man with a history of choledocho-lithiasis and cholecystectomy presented with recurrent epigastric pain, fever, and elevated infection markers. He was initially managed as a case of possible ascending cholangitis with oral antibiotics, which failed to treat the infection. Due to clinical deterioration, a CT abdomen and pelvis was arranged to investigate the aetiology. The CT images revealed pneumobilia, signs of cholangitis with intrahepatic duct dilatation, and evidence of a liver abscess. His blood cultures grew Streptococcus constellatus, Streptococcus anginosus, and Klebsiella pneumoniae. Subsequent treatment with IV ceftriaxone and metronidazole led to resolution of the pneumobilia and hepatic abscess formation on follow-up MRI liver scan. This suggests that the pneumobilia likely persisted due to gas-forming bacteria, particularly Klebsiella pneumoniae. The persistence of Streptococcus anginosus highlights the need for prolonged, sensitivity-based antibiotic therapy to fully eradicate virulent biliary infections and prevent complications such as hepatobiliary abscess. Follow-up radiological investigation to check resolution of pneumobilia and cholangitis post treatment with targeted antibiotic therapy is crucial to prevent complications, and if there is persistence of radiological evidence indicating infective changes, the antibiotic course should be prolonged.