Does bile of patients with acute gallstone pancreatitis cause pancreatic inflammatory lesions? A study of the pancreatic toxicity of choledochal secretions collected at ERCP

Background: Bile flow into the pancreatic duct has been proposed as the cau se of acute biliary pancreatitis. However, the pancreatic toxicity of chole dochal bile from patients with acute gallstone pancreatitis has not been st udied. Methods: Bile was collected endoscopically from the common bile ducts of 21 patients with acute gallstone pancreatitis within 72 hours after the onset of disease. The bile samples were instilled into the pancreatic duct of ra bbits, and light microscopic examination of the pancreas morphology was per formed to assess the toxicity of human bile. Microbiologic quantitative ana lysis of the aerobic and anaerobic bacterial bile flora was performed. Results: Bile of six patients with acute gallstone pancreatitis (29%) induc ed interstitial inflammation in the rabbit pancreas. Choledochal bile of th ese patients harbored more than 10(4) CFU/mL bacteria (Proteus vulgaris, n = 1; Klebsiella pneumoniae, n = 1; Escherichia coil, n = 2; enterococci, n = 2). After sterilization, the bile samples did not induce acute pancreatit is. In 15 patients (71%), bile did not cause acute pancreatitis in the rabb it pancreas. These choledochal secretions were sterile or contained less th an 104 CFU/mL. Conclusions: Reflux of infected bile may be a potential cause of acute panc reatitis in the minority of patients with bacterobilia. In most patients wi th gallstone pancreatitis, bile is neither infected nor harmful to the panc reas, and its flow into the gland is unlikely to be the cause of inflammati on.