The Research On Extrahepatic Bile Duct Injury After Liver Transplantation Caused By Ischemic Reperfusion

In 1963, the first orthotopic liver transplantation in human body was completedby Starzl, from then on, the whole world has entered the period of livertransplantation. Although the success rate of liver transplantation is more than 90%,the occurrence of complications after operation still hinder the improvement ofsurvival rate after liver transplantation. In which the complication of biliary tractoccurred usually, the incidence rate is 9%--30%. It bring serious influence to patient.With the improvement of transplantation skill and the treatment to the period ofsurrounding operation, the occurrence of other complications decreased rapidly whileit keeps high level on the occurrence of complication on biliary tract. Medicalresearches find that the reconstruction of biliary tract, ischemia-reperfusion injury,immunological rejection and infection are the main reason of functional lesion andstructural change of biliary tract after liver transplantation. It is important to study thereason, nosogenesis and measure of the occurrence of complication on biliary tract, sowe can lower the incidence rate and improve the survival rate as well as the quality oflife of patient.PartⅠEstablishment and significance of orthotopic autologues livertransplantation model with bile ducts ischemia-reperfusion injury in rats Objective: Every technological progress of liver transplantation has closerelationship with basic research. The development of basic research is on the base ofanimal test. So creating an ideal animal model is very important to do the study onliver transplantation. The liver transplantation in rat is the ripest animal model whichis used widely and successfully. The "two-cuff technique" animal model in ratmetioned by Kamada is used widely, but it does not coincide the hepatic artery. It isnecessary to establish a ideal animal model, so we can make further study on pathoand physio course of bile ducts ischemia-reperfusion injury.Martial and Methods: 102 SD rats were deployed to establish the model. Themethod of this model was as same as the one in orthotopic liver transplantation exceptthe blood vessel anastomosis, and it perfused into portal vein and abdominal aortawith constant pressure. The portal vein and the hepatic artery reperfusion werecontrolled by artery clamp.Results: The success rate after the operation was 95.6% (97/102) and anhepaticphase was (16.17±0.92) min. The time of hot and cold ischemia and reperfusion couldbe accuracy controlled. The effect of double constant pressure perfusion is fine. Thereis no akaryocyte on the paries of biliary tract under the light microscope after theperfusion.PartⅡThe research on extrahepatic bile duct injury caused by corr warmischemaObjective: The liver grafts bile duct will experience warm ischemia andkryo-conservationinjury, rewarming injury, corr warm ischema injury and reperfusioninjury. The warm ischemia and kryo-conservation injury was studied thoroughly, butthere is little research on arteria hepatica ischemic time which has the closerelationship with bile duct complication after operation. So it is important to make the research so as to make sure of the safely time of corr warm ischema.Material and methods:1. The groups of test animals and the collected examples: Divide 102 SD rats into 5groups: GroupⅠ, sham operated; GroupⅡ, PV, HA are opened at the same time;GroupⅢ, HA is opened 30 min after PV; GroupⅣ, HA is opened 1 hour after PV;Group V, HA is opened 2 hours after PV. The examples are collected from GroupⅡto GroupⅤon the time of 1 hour and 2hour after the opening of hepatic artery.2. Observing Index: The apoptosis detection on extrahepatic biliary tract—TUNELand the extrahepatic biliary tract pathomorphism.3. Appraisal methods: the number of apoptosis: Choose 10 campus visualis fromevery chip under light microscope (×400), calculate the total number of cells andapoptosis, and divide the number of cell by the number of apoptosis get the AI. Thepathomorphism score: 0, There is no damage on bile duct mucous membrane cell andsubmucosal gland cellula epithelialis; 1, There are damages on bile duct mucousmembrane, the number is less than 10%; no damage on submucosal gland cellulaepithelialis; 2, There are damages on bile duct mucous membrane, the number isbetween 10%--30%; the damage on submucosal gland cellula epithelialis is less than10%; 3,The damage on bile duct mucous membrane is more than 30%, the damage onsubmucosal gland cellula epithelialis is between 10%--30%.4. Statistical analysis: SPSS 13.0 is used in the analysis. The results are expressed as (?)±s, variance analysis adopted in the comparison between several means.Results:1. There are slight apoptosis on bile duct cell in GroupⅠ; from GroupⅡto GroupⅤ,the longer the time extended on corr warm ischema, the more apoptosis got. Compareeach group with GroupⅠ, we get statistical significance (P=0.00). Also we can getstatistical significance about the bile duct endothelial cell apoptosis on the time of 1 hour and 2 hour(P=0.00). The statistical significance exists in the comparison between eachgroup on the time of 1 hour and 2 hour after HA reperfusion (P＜0.05).2. The comparison between different parts of extrahepatic biliary tract: From GroupⅡto GroupⅣ, there is no statistical significance in the comparison between thesuperior part and subjacent part of bile commen duct dodecadactylon (P＞0.05). Butwe can get the statistical significance from the comparison between porta hepatis bileduct and the superior part, the subjacent part of bile commen duct dodecadactylon. InGroupⅤ, The statistical significance exists in the comparison between any two of thethree parts (P＜0.05).Conclusion:1. The operation simulates the whole process of orthotopic liver transplantation and issimple and feasible. It also make sure of the liberation order and reform the perfusionway. Through the model, we can see the injury on bile duct made by cold ischema,corr warm ischema and reperfusion directly, objectively. Besides, the model can beused on the research on the break order of portal vein and hepatic artery.2. Apoptosis is another manifestation of extrahepatic bile duct endothelial cell injurymade by ischemia-reperfusion.If there is no difference between warm ischema andcold perfusion, the relationship between the extended time of corr warm ischema andthe apoptosis of bile duct endothelial cell keeps time—effect. The apoptosis ofextrahepatic bile duct endothelial cell, liver cell and intrahepatic bile duct endothelialcell will take place early in ischemia-reperfusion injury.3. The injury degree of bile duct and the time of corr warm ischema keep directcorrelation. If the PV and HA can not be reperfusion at the same time, we'd bettershorten the time of corr warm ischema within 1 hour(30 minutes is the best),otherwise, the bile duct complication rate which is caused by worse bile duct injurywill increase. 4. The most serious injury occurred in the bile duct of portal hepatic, the more seriousinjury occurred in the distal end of bile comment duct, and the light injury occurred inthe proximal end of bile comment duct. In the liver transplantation operation, we shallpay more attention to protect bile duct circum-constitution when we trim the livergraft, do not librate more bile ducts towards porta hepatis, the proximal end of bilecommen duct should be treated as right part when we coincide bile duct.