Acute Cholangitis

Acute cholangitis is a bacterial infection within an obstructed biliary tree. Choledocholithiasis is the dominant cause, but a benign or malignant stricture, an occluded or migrated biliary stent, extrinsic compression, or recent ERCP instrumentation can create the same problem. Common organisms include Escherichia coli, Klebsiella, Enterobacter, and Enterococcus; infection is often polymicrobial. The obstruction does more than prevent bile drainage. Bile accumulates above the blockage, intrabiliary pressure rises, and bacteria and endotoxin can pass through the biliary epithelium into hepatic sinusoids and the systemic circulation. This cholangiovenous reflux explains why a process that began in a duct can rapidly produce bacteraemia, hypotension, organ dysfunction, and septic shock. Antibiotics suppress the bacterial burden, but the infected obstruction remains until the duct is decompressed. The cause also predicts the next problem. A stone may require duct clearance and later management of the gallbladder. A stent may need exchange or removal. A malignant stricture may require tissue diagnosis and a longer-term drainage plan. Treating the infection without addressing the obstruction invites persistence or recurrence.