Bacterial translocation from the biliary tract to blood and lymph in rats with obstructive jaundice

The disruption of the hepatocyte tight junctions observed in biliary obstruction suggests altered permeability of the blood-bile barrier. In this study the role of biliary obstruction and increased biliary pressure on the translocation of bacteria from biliary tract to bloodstream and lymphatic system were evaluated.

Rats underwent distal bile duct ligation (BDL, n = 33) for two weeks or a sham celiotomy (n = 21). Seventeen of the 33 BDL rats underwent subsequent biliary decompression by a choledochojejunostomy (CJ). Two weeks after the final operation, a laparotomy was performed again and the CBD, the thoracic duct, and the caval vein were canulated. Next, a suspension containing 10(8) Escherichia coli/ml was retrogradely infused in the CBD for 5 min at 5 or 20 cm H2O above the secretory biliary pressure.

A higher biliary infusion pressure resulted in a significant increase of cfu E.coli per milliliter of blood in all the three groups (Sham, BDL, CJ). BDL rats showed significantly more bacterial translocation to the bloodstream than the shams. After biliary decompression, translocation normalized to the control levels. At 5 cm H2O infusion pressure only one lymph culture was positive (CJ group). At 20 cm H2O overpressure, nine lymph cultures were E.coli positive (P = 0.03). These were found mainly in groups with a nonobstructed bile duct (Sham and CJ 40% vs BDL 10%).

Translocation of bacteria from biliary tract to bloodstream increased at higher intrabiliary pressures. Longstanding bile duct obstruction was an independent determinant for cholangiovenous reflux. Bacterial translocation to the lymphatic system did not parallel translocation to the bloodstream, although in the nonobstructed biliary tract, increased bacterial translocation to the lymphatic system was pressure related.