Objective: Cholangitis is, after haemorrhage and pancreatitis, the most frequent complication of ERCP with a relatively high lethality. The objective of the study was to evaluate the importance of antibiotic prophylaxis on the development of cholangitis in exclusively endoscopic treatment of biliary obstruction, assessment of the effect of antibiotic prophylaxis on bacteriaemia, assessment of the bacterial contamination of bile and evalua- tion of complications in general. Methods and patients: The suthors included in the prospective multicentre controlled study patients with signs of biliary obstruction where treatment of bilary obstruction was successful after a single session. Com- plications were followed up also in the other patients. To the treated group Amoksiklav in amounts of 2.4 g was administered. Results: The study comprised a total of 276 patients and 244 protocols were evaluated. The most frequent finding was choledocholithiasis followed by stenoses of the bilary pathways and stenosis of the papilla of Vater (109, 49, 36 patients). The authors recorded a total of 51 complications: 20 times haemorrhage from the papilla of Vater, 22 cases of acute pancreatitis and 8 of cholangitis. Two patients died: one after haemorrhage from the papilla of Vater and another one after perforation of the duodenum, haemorrhage and pancreatitis. The controlled trial comprised 202 patients. In the antibiotic groups haemorrhage was developed by 5, pancreatitis by 6 and cholangitis by 4 patients. In the control group haemorrhage in 8, pancreatitis in 10 and cholangitis in 3 patients, the differences between the two groups were not significant. The haemoculture was positive in 18 of 73 patients in the antibiotic group and in 24 of 84 patients in the control group. The most frequently detected bacteria were Staphylococcus epidermidis, Escherchia coli, Streptococcus viridans and Klebsiella spuriae. The bacteriological finding in bile was positive in 28 of 67 examined patients in the antibiotic group and in 50 of 78 patients in the control group. The most frequently detected bacteria were Escherichia coli, Streptococcus viridans, Klebsiella spuriae and Pseudomonas aeruginosa. The mean bilirubin value in 7 patients with complicating cholangitis was 131 (70–350) mmol/l, the mean bilirubin value in the remainder was 78 (5–350) mmol/l, and this difference was statistically significant. Conclusion: Antibiotic therapy before therapeutic ERCP does not reduce the risk of complicating cholangitis and did not influence the bacteriaemia. Antibiotic administration before ERCP in case of biliary obstruction to prevent cholangitis is therefore not justified. The bacteriological profile of bile is consistent with published data. The presented conclusions should markedly reduce the total costs for encdoscopic treatment of biliary obstruction.

        Key words: antibiotic prophylaxis – cholangitis – endoscopic treatment – biliary obstruction