Internal Biliary Drainage Is Superior to External Drainage in Reversal of the Elevated Serum Endotoxin, Interlukin-2 and Interlukin-6 in Rats with Obstructive Jaundice

Abstract

Backgrounds: The roles of preoperative relief of obstructive jaundice by internal or external biliary drainage in prevention of postoperative complications remain controversial. Aims: To investigate the effects of biliary drainage on reversion of the abnormal serum endotoxin, interlukin-2 (IL-2) and interlukin-6 (IL-6) in rats with obstructive jaundice. Methods: Sixty male adult Sprague-Dawley rats were randomly assigned to four groups: obstructive jaundice (OJ; n = 15) by bile duct liagation and resection for 7 days and re-operation for sham drainage for another 7 days; internal biliary drainage (ID; n = 15) by bile duct ligation and resection for 7 days and re-operation for planting a stent between the dilated bile duct and the duodenum for another 7 days; external drainage (ED; n = 15) by bile duct ligation and resection for 7 days and re-operation for exteriorizing a drainage tube from the common bile duct through the subcutaneous channel to the nape of the neck; and sham operation (SH; n = 15). On the day 7after the second operation (14 days following the first operation), the rats were succumbed and blood specimens were collected. The concentrations of serum IL-2 and IL-6 were measured with enzyme linked immunosorbent assay (ELISA) and serum endotoxin level was measured by limulus test. Results: Endotoxemia was found in rats with OJ and the concentration of serum endotoxin in jaundiced rats (42.5 ± 3.5 pg/ml) was significantly higher than that in sham operation rats (4.1 ± 2.0 pg/ml) (P<0.01). After bile duct ligation, the concentration of serum IL-6 (212.9 ± 56.5 pg/ml) was significantly increased comparing with that in sham rats (145.3 ± 38.7pg/ml) (P<0.01). The level of serum IL-2 (212.7 ± 62.4 pg/ml) was also elevated, but the difference was not statistically significant comparing with that in sham rats (183.2 ± 59.6pg/ml). After relief of the biliary obstruction by ED, the endotoxemia was reversed (6.2 ± 2.9pg/ml) (ED vs OJ, P<0.01). The levels of interlukin-6 and interlukin-2 could not be decreased, on the contrary, they were significantly increased (269.4 ± 76.2 pg/ml and 264.9 ± 62.3pg/ml respectively) (ED vs OJ, P<0.01 and P<0.05 respectively). However, internal drainage could suppressed not only the endotoxemia (4.2 ± 2.0pg/ml), but also the serum IL-6 (169.7 ± 49.1 pg/ml) and IL-2 (184.3 ± 52.4 pg/ml) (ID vs OJ, P < 0.01, P < 0.05 and P>0.05 respectively). Conclusions: Internal biliary drainage is superior to external drainage in terms of reversal of the abnormal serum endotoxin, interlukin-2 and interlukin-6 in rats with obstructive jaundice.