Effect Of Biliary Drainage On Liver Function And Histopathology In Rats At Different Time After Obstructive Jaundice

Objective:Obstructive jaundice can lead to a series of pathophysiological changes of the liver and the whole body system,damage the liver function and increase the risk of operation,and biliary drainage can relieve the obstruction of the bile duct and restore the function of the liver.However,there are great differences in the effect of biliary drainage between different patients,what causes the difference,there is still no perfect explanation.The preoperative use of biliary drainage to reduce jaundice in patients with obstructive jaundice was once highly praised by hepatobiliary surgery.However,in recent years,a large number of clinical studies have questioned the problem of preoperative biliary drainage.It is considered that it does not benefit the patient.What are the influencing factors in this,which are worth exploring.Regarding the mechanism of liver injury,biochemical indicators and the pathological changes of liver tissue after biliary obstruction,a large number of animal and clinical experiments have been systematically elaborated,but there are few detailed reports on the changes after biliary drainage.In this study,the model of obstructive jaundice and biliary drainage in rats was established to observe the changes of liver function and histopathology,and to explore the changes of liver function and histopathology before and after biliary drainage.The results of this study are expected to further elucidate the pathophysiological changes of the liver after obstructive jaundice and biliary drainage,and to further explore the factors affecting the effect of biliary drainage and the recovery rate of liver injury after drainage.It is expected to provide some theoretical basis for guiding the clinical application of preoperative jaundice reduction.Methods:The model of biliary obstruction and drainage was established in 55 healthy adult SD male rats by ligating common bile duct and inserting external drainage tube.Then animals randomly divided into 3-day external drainage group(group A),7-day external drainage group(group B),14-day external drainage group(group C),21-day external drainage group(group D),28-day external drainage group(group E)and control group.Serum total bilirubin(TBIL),direct bilirubin(DBIL),alanine aminotransferase(ALT),alkaline phosphatase(ALP),prealbumin(PA)and prothrombin time(PT);were measured before drainage and at 3 days,7 days,14 days,21 days,28 days and 35 days after drainage to investigate the changes of liver function.liver tissue samples were collected at different time points to observe the pathological changes.Results: With the prolongation of the time of obstruction,the increase of TBIL,DBIL,ALT,ALP,the decrease of PA and the prolongation of PT showed that the liver function damage was gradually increased;the pathological changes of the liver were from the degeneration,necrosis to the proliferation of the epithelial cells of the region and hepatic lobular structure failure,and eventually led to the fibrosis of the liver.After drainage,liver function and pathological injury gradually recovered,but the longer the obstruction time was,the slower the recovery was.In the group with short time of obstruction,the liver function and the tissue morphology can be restored to the normal level in a short time;but the group with long obstruction time can not return to normal even after a long time of drainage.Conclusion: The duration of biliary obstruction is the critical factor to influence the degree of liver injury and the recovery rate of obstruction.Biliary drainage was performed at different time after obstructive jaundice in rats,and the liver function and histopathological recovery rate were significantly different.If the obstruction time reaches a certain degree,the liver injury may be difficult to reverse even if the obstruction is relifted.The results of this study showed that biliary drainage can achieve superior effect in rats with biliary obstruction within 2 weeks,and the effect of biliary drainage is not very satisfactory if the obstruction time is more than 2 weeks.