Changes in biliary bacteria after endoscopic cholangiography and sphincterotomy.

This prospective study consisted of 32 patients. In each patient, bile was collected during two separate endoscopic retrograde cholangiopancreatographies (ERCP) to study changes in biliary bacteriology and cytology. The mean interval between ERCPs was 20 months (15-29 months). Twenty-three patients had gallstones in the gallbladder, bile ducts, or both. Nineteen of them had bactibilia compared to none of the 9 patients with normal ERCP (P less than 0.001). Fifteen patients had normal bile ducts in ERCP (Group 1). Four of these patients (27%) had bactibilia initially and 9 (60%) at follow-up (P = 0.069). Seventeen patients had bile duct stones and underwent endoscopic sphincterotomy (Group II). Fifteen of these patients (88%) had bactibilia initially, and 15 (88%) also had bactibilia at follow-up. Initially, anaerobic bacteria were detected in 37 per cent of Group I patients with bactibilia and in 50 per cent of Group II patients with bactibilia. At follow-up, the bile in Group I patients infrequently (11%) contained anaerobes, whereas in Group II patients anaerobes predominated (67%; P less than 0.011). Clear correlation between the biliary cytology and bacteriology could not be observed. The authors conclude that ERCP may result in increased incidence of long-term bactibilia and suggest that contamination occurred during ERCP. The bactibilia associated with bile duct stones does not subside after endoscopic treatment of the common duct stones.