The Effects Of Internal And External Biliary Drainage On The Lung Injury In Rats With Obstructive Jaundice

【Background】 Obstructive jaundice (OJ) is associated with highpostoperative complications and mortality, often complicated by infection,hemorrhage, liver and kidney dysfunction, indicating that obstructive jaundicemay be a syndrome which can be secondary to change multiple organs inmorphology and function. Our previous study has found that there wereendotoxemia, impaired immune and liver function in rats with obstructivejaundice, which could be suppressed by internal biliary drainage, but not byexternal biliary drainage, and there were thickened fibrous tissue and increasedinflammatory cells in the interstitial of lungs in pathology of rats with OJ. Lunginjury has become a hot research focus. However, there are few researches aboutobstructive jaundice causing lung injury. The effects of biliary drainage on lunginjury are unclear in rats with obstructive jaundice.【Aims】The aim of the present study was to investigate that whetherobstructive jaundice can cause lung injury or not and the effects of biliarydrainage on lung injury in rats.【Methods】Sixty-eight male adult Sprague-Dawley rats were randomlydivided into four groups: obstructive jaundice (OJ, n=17), internal biliary drainage(ID, n=17), external biliary drainage (ED, n=17) and sham operation (SH, n=17).OJ was established by common bile duct (CBD) ligation and division, SH wasproduced by separating CBD locally but not dividing, and specimens of OJ andSH were collected on the15thday after the operation. ID was performed byimplanting a drainage tube between the dilated end of CBD and duodenum on the15thday after the operation of OJ, and ED was performed by exteriorizing adrainage tube at the nape on the same day as ID. On the15thday after the secondoperation specimens were taken from ID and ED. On the specimens collection day,the abdominal aorta’s blood was detected by arterial blood gas analysis, and lungtissue was collected: left lung tissue was homogenated to10%by physiologicsaline; right upper lung tissue was toasted for24hours (80℃) in order to calculate lung wet-to-dry weight ratio (W/D); right down lung tissue was harvested forstudy of pathology. The concentration of tumor necrosis factor-α (TNF-α) andinterleukin-6(IL-6) in lung homogenate were measured with enzyme linkedimmuno sorbent assay (ELISA) and Neutrophil elastase (NE) level was detectedby biochemistry test.【Results】Rats models were successfully established. After bile ductligation for14days, there were more inflammatory cells in the interstitial of lungsand thicker alveolar septum was found in pathology of OJ rats than SH; lung W/Dwas elevated (5.72±0.83vs5.01±0.67, P<0.05); the pH and PaCO2weredecreased(P<0.05)(7.349±0.034vs7.371±0.030;41.95±6.80mmHg vs46.12±4.53mmHg) in arterial blood gas analysis, and the cHCO-3and BE weremarkedly decreased(P<0.01)(22.57±4.40mmol/L vs26.06±1.88mmol/L;-3.01±4.17mmol/L vs0.44±1.73mmol/L); the level of TNF-α and IL-6in lunghomogenate became higher(P<0.01)(100.89±21.27pg/ml vs64.09±13.03pg/ml;66.95±15.15pg/ml vs42.62±13.70pg/ml), the lung NE wasincreased(50.47±16.84ug/ml vs39.64±9.33ug/ml, P<0.05). After relief ofobstructive jaundice by internal biliary drainage, compared to OJ, the PaCO2of IDwas elevated (46.44±5.31mmHg, P<0.05) and almost reversed to SH; the level oflung TNF-α was markedly decreased (75.14±15.85pg/ml, P<0.001) and IL-6wasdecreased (54.35±14.09pg/ml, P<0.05). When external biliary drainage wasperformed, the pH of ED was continued to decrease compared to OJ (7.286±0.091,P<0.05); compared to SH, the SaO2of ED was decreased (87.04±12.95%vs93.78±1.93%, P<0.05), and the cHCO-3and BE were markedlydecreased(P<0.001)(19.81±5.09mmol/L,-6.55±5.52mmol/L), the BE was lowerthan that in OJ (P<0.05); the lung TNF-α and IL-6of ED were higher than that inOJ (112.13±36.89pg/ml,70.79±22.74pg/ml). Internal and external biliarydrainage both could mitigate the inflammation of lung pathology, ID, but not ED,almost reversed to the level of SH. The level of lung NE was decreased in both IDand ED (39.39±12.41ug/ml,44.81±16.15ug/ml), however, there was significantdifference between ID and OJ (P<0.05) and no difference between ED and OJ(P=0.32); moreover, after internal drainage, the NE level almost reversed to thelevel of SH (P=0.95). 【Conclusion】 Obstructive jaundice could induce lung injury on rats,displaying with the inflammation of lung pathology, elevated the level ofinflammatory cytokines and neutrophil elastase in lung, and increased lungwet-to-dry weight ratio. Internal and external biliary drainage both could reversethese changes in different level, except the lung inflammatory cytokines becomemore after external biliary drainage; however, internal biliary drainage was betterthan external biliary drainage on relieving lung injury.