Clinical Research About Hepatic Function Reserve Before Hepatectomy In Obstructive Jaundice Status

Objective:(1) To establish a reliable definition of postoperative liver dysfunction (PLDF) in obstructive jaundice status undergoing hepatectomy.(2) To analyze the prognostic factors for PLDF and explore the critical value of standardized remnant liver volume ration (SRLVR) to predict PLDF in obstructive jaundice status undergoing hepatectomy by means of liver volumetry.Methods:(1) A retrospective clinical analysis was conducted in the cases of hilar cholangiocarcinoma (HCC) in obstructive jaundice status undergone major hepatectomy in Chinese PLA General Hospital from Jun2005to Apr2011. The postoperative rate of decrease of serum bilirubin was calculated according to the equation y=a*ebx,where "y" is the serum total bilirubin level on postoperative day7(TB7),"a" is represented bilirubin levels just after the operation,"x" is the number of days after surgery,"e" is the base of the natural logarithm and "b" is the rate of decrease of serum bilirubin. Analysis on prognostic factors for dying of liver failure were conducted. Receiver operating characteristics (ROC) analyses were used to define the cut-off value of TB7and "b" value to predict PLDF. The reliability of these threshold values for predicting the morbidity and length of stay after surgery was assessed.(2) The standardized remnant liver volume ration (SRLVR) was expressed as ratio of remnant liver volume (RLV) to standard liver volume (SLV) which was calculated by body surface area (BSA). ROC analyses on SRLVR and preoperative bilirubin level were performed to define their critical values for PLDF. Univariate analysis and multivariate Logistic regression analysis were performed to delineate perioperative prognostic factors for PLDF.Results:(1)Altogether,117cases of HCC in obstructive jaundice status underwent major hepatectomy. The number of cases died of liver failure after surgery was8(6.8%).The postoperative complications were occurred in49cases (41.9%), the major complications were occurred in18cases (15.4%), the infectious complications were occurred in23cases(19.7%). The mean duration of hospital stay after surgery was17.8days (5～64days). Univariate analysis showed that the significant prognostic factors for dying of liver failure were operative time(P=0.039),TB7(P=0.008),"b"value(P=0.02), level of albumin after surgery(P=0.017), vascular resection and reconstruction(P=0.015), preoperative biliary tract infection (P=0.028). The cut-off values of TB7and "b" value to predict dying of liver failure determined by ROC analyses were104.35μmol/L(AUC0.88895%CI0.782～0.993) and-0.032(AUC0.87095%CI0.756～0.985), respectively. When combined these two values, the accuracy(Se75%,Sp89.9%,PPV35.3%, NPV98.0%) to predict dying of liver failure was better than that considered individually(Se87.5%, Sp72.5%,PPV18.9%,NPV98.8%and Se87.5%, Sp84.4%, PPV29.2%, NPV98.9%, respectively). According to this combined criteria,all cases were divided into2groups and comparisons between groups showed that overall mobidity rate(P<0.001) incidence of infectious(P=0.006)and major complication (P=0.001) were significantly different while length of stay after surgery (P=0.051) was not significantly different.(2)PLDF occurred in17patients(14.5%). The cut-off values of SRLVR and preoperative bilirubin level to predict PLDF determined by ROC analyses were41.2%(AUC0.88895%CI0.782～0.993) and186.7μmol/L (AUC0.69995%CI0.569～0.829), respectively. The multivariate Logistic regression analysis showed that the preoperative bilirubin level>186.7μmol/L (OR=17.288,95%CI1.967～151.918, p=0.01) and SRLVR<41.2%(OR=71.626,95%CI8.067～635.955,p<0.001) were the independent prognostic factors for PLDF individually.Conclusions:(1) The PLDF is defined as the serum total bilirubin level on postoperative day7is greater than104.35μmol/L and the postoperative rate of decrease of serum bilirubin is greater than-0.032.(2) The critical value of SRLVR to predict PLDF in obstructive jaundice status undergoing hepatectomy is41.2%. The multivariate Logistic regression analysis showed that the preoperative bilirubin level>186.7μmol/L and the SRLVR<41.2%are the independent prognostic factors for PLDF individually.