Clinical factors associated with positive bile cultures during primary percutaneous biliary drainage

To evaluate the utility of routine bile cultures and to determine the risk factors for bacterial colonization of the bile as well as the biliary flora in patients with biliary obstruction undergoing primary percutaneous biliary drainage.

Between October 1995 and January 1997, bile cultures were prospectively obtained in all patients undergoing percutaneous biliary drainage. Seventy-six patients underwent 86 procedures. Culture results were correlated with clinical, laboratory, and demographic variables. The antibiotic sensitivities of cultured organisms were examined.

Fever, previous endoscopic or percutaneous biliary instrumentation, and bilioenteric anastomosis were significant predictors of a positive bile culture. In the absence of any of these indicators, bile cultures were unlikely to be positive. Enterococcus species was the organism isolated most commonly. Yeast, gram-negative aerobic bacilli, and Streptococcus viridans followed in frequency.

Bile cultures provide valuable information that was useful for planning antibiotic prophylaxis and treatment. The likelihood of positive bile cultures can be predicted based on certain clinical variables. Continued investigation is needed to better predict bacterial flora in individual patients. Given the association between previous instrumentation and biliary colonization, noninvasive imaging modalities should be exhausted before invasive procedures are performed for solely diagnostic purposes in patients with biliary obstruction.