Analysis Of High Risk Factors For Biliary Tract Complication Following Liver Transplantation

IntroductionAs the organ preservation, anaesthetic, immunosupressant and surgical techniques improved, liver transplantation has achieved much progression and the long-term survival rate of patients receiving liver transplantations has apparently risen during the last decade. But the incidence of biliary complications (BC) after liver transplantations remains high about 8-25% and mortality about 1-5%.BC has become one of the major causes of death, that can extensively damage the biliary tree of grafts, lead to the dysfunction of graft and even threaten the lives of patients. The research on BC has achieved great advancements in recent years, but many problems still remain. To determine the risks of pre-,intra-,and post-operative factors that lead to the occurrence of BC and make efforts to prevent it from happening , diagnose it early and care it effectively could surely reduce the morbidity,mortality of BC and improve the long-term effect of the operation.ObjectiveTo explore the relative high risk factors contributing to the development of biliary complication(BC) in a large subjects undergoing liver transplantations(LT) retrospectively, and seek to provide theoretical evidence to prevent the occurrence of BC.Specific aims include identifying predictor of BC that is easily obtained and commonly accessible so as to care patients in pre-,intra-,and post-operative terms effectively. We also wish to find some useful informations so as to help to diagnosis and therapy of BC.Material and MethodsThe clinical data of 181 patients receiving LT from Jan.2004 to Dec.2008 were collected completely. Preoperative variables includes sex, age, primary diseases, ABO-blood type, warm ischemic time (WIT), cold ischemic time(CIT) and Child-Turcotte-Pugh(CTP) score. Intraoperative variables includes LT style, biliary reconstruction type and the second warm ischemic time. Postoperative variables includes hepatic arterial peak velocity(HApeak), resistive index(RI), portal venous mean glow velocity(PVmean), cytomegalovirus(CMV) infection , acute rejection(AR) and chronic rejection. We also monitored the process of the biliary tree intimately with MRCP or ERCP and some clinical manifestations. A retrospective analysis was performed to reveal the influence of factors mentioned above on BC incidence. The related factors between 04-05year and 06-08year group were assessed with univariate analysis. In the univariate analysis, categorical variables were analyzed using a Pearson's X2 test or Fisher's exact test, and continuous variables were compared by using the student's unpaired t-test. Datas iare presented as X±SD for continuous variables and as percentage for categorical variables. Differences were considered significant with P values less than 0.05. Those variables between all manner of BC and non-BC group were included in the multivariate analysis. The relevant factors of BC was evaluated by using a binary forward stepwise logistic regression analysis to estimate odds ratios (OR) and their 95% confidence intervals( CI). Some indexes of liver function such as TBIL, ALT, ALP, GGT were also compared between BC and non-BC group.The Statistical analysis was performed with SAS9.1.3 for Windows software system.Results26(14.4% ,BC group) recipients developed BC, including 21 strictures,6 leakages,1 single infection,1 intrahepatic cholestasis and 1 stone, there was no evidence of BC in the other 155 recipients (non-BC group). 20 out of 95(04-05y group) patients received LT from Dec.2003 to Dec2005 and 6 out of 86(06-08y group) patients received LT from Jan.2006 to Dec 2008 developed BC, their morbilities have significant difference.By means of univariate analysis between group 04-05y and 06-08y, we find significant difference on incidence of BC , and, the risk factors associated with BC were not only biliary reconstruction technique(P=0.0012), intraoperative blood loss (P=0205), PVmean in 2 week after operation (P=0.0167) and anhepatic phase(P=0.0308) but also cold ischemic time(CIT) and second warm ischemic time(WIT2).Stepwise logistic regression analysis revealed that HARI, placement of "T" tube were independent risk factors of predicting BC. HARI also was independent risk factor associated with BC above ClavienⅢb. It is uncertain about extension of anhepatic phase could increase the incidence of BC above ClavienⅣ. HARI in 1 week after operation was a independent factor for non-anastomotic BC. HARI was also an independent factor for ischemic-type BC. For anastomotic BC, not only HARI of the first day postoperative and primary diseases(PBC) but also other vaso-complication could increase its incidence.ConclusionBC remains a major problem after liver transplantations. Modification of reconstruction technique including improvement of saturation can reduce BC incidence. Placement of "T" tube may increase the incidence of BC but have nothing to do with the development of ischemic-type BC, non-anastomotic BC and BC above ClavienⅣ. Hepatic arterial insufficiency(HAI) was an independent risk factor for ischemic-type BC and non -anastomotic BC, the monitoring protocol of hepatic hemodynamics by color dopplar ultrasonography should be enhanced, which contributes to recovery of normal hepatic hemodynamics. To shorten cold ischemic time and second warm ischemic time could cut down the incidence of BC above ClavienⅢb. To coincide the artery precisely can prevent the occurrence of BC threaten lives and above ClavienⅢb undoubtedly. Moreover, it is necessary to avoid CMV infection ,acute and chronic rejection. The obvious difference of increasing range of ALP, GGT between BC and non-BC may be contributive to diagnose BC earlier and forecast the prognosis of BC,so does the abnormal values of RI. We should to carry out systematic prophylaxis in order to reduce the incidence of BC.