The Application Of Indocyanine Green Excretion Test In The Assessment Of Liver Disease

Background: Liver diseases threat the health of human seriously.Due to etiological complexity, assessment of liver function remains a big problem in the clinical. At present, the assessing methods of liver function were divided into static and dynamic examination.In clinical, static test is the method used commonly, including bilirubin, clotting factor, albumin,et. But because of the complexity of the liver function,static test of liver cannot reflects the dynamic changes of liver function promptly which is required during the dynamic monitoring of patients. Dynamic test can guide clinical doctors to accurate judgment of the disease on the basis of static test. By combining static and dynamic tests, dynamic assessment is an inevitable trend in the field of treatment for liver disease.Indocyanine green excretion test (ICG) is the most widely used method among the dynamic tests of liver. DDG-3300K is used to measure the blood ICG concentration. This instrument makes such measure -ments continuously by monitoring the optical absorption at wavelengths of 805 and 940 nm, based on the principle of pulse spectrophotometry. The ICGR15 and K are calculated automatically from the blood ICG concentration time course.The speed of ICG excretion depends on the amount of liver cells damaged and the function of liver cells.So it can be used to assess the amount of liver cells and reflect the liver reserve function. Recent studies show that there are correlationship between the ICG parameters and Child-Pugh, MELD scores.Objective: To investigate the effectiveness of Indocynine green excretion test for assessing the reserve function of cirrhosis and cancer,to discuss the relationship between ICG and Child-Pugh sore, MELD scores, LSM,some biochemical parameters.Methods: Collect 512 patients with chronic liver disease accepting the examination of Indocynine green excretion test who were from hospitalized in First Hospital of Jilin University from May,2009 to January,2011 (including 265 patients with hepatic cirrhosis,238 patients with hepatocellular carcinoma, 9 patients with liver failure).Patients are between 21-82 years old, including 378 male and 134 female, average age is(54.01±10.64). According to different causes, 265 patients with hepatic cirrhosis were classified: 141 patients with cirrhosis of HBV, 61 patients with cirrhosis of HCV, 42 patients with alcoholic cirrhosis, 15 patients with primary biliary cirrhosis, 6 patients with autoimmune posthepatic cirrhosis.All patients were classified by Child-Pugh grade.The ICG excretion test (K value and ICGR15) was performed by ICG pulse spectrophotometry (DDG-3300K), and the MELD scores of patients were calculated. Biochemical parameters including ALB, TBIL, CHE, PTA were also examined. LSM value of the patients who both examined by the ICG excretion test and FibroScan were marked. Correlation analysis between ICG test and those indexes were conducted.Results: Of 512 patients with chronic liver disease,there are 164 patients in Child-Pugh A whose average MELD score were 4.210±3.711, average ICGR15 were(16.925±12.658)%,average K value were(0.139±0.057)/min; 215 patients in Child-Pugh B whose average MELD score were 7.400±4.339, average ICGR15 were(32.983±15.783)﹪,average K value were (0.083±0.039)/min; 133 patients in Child-Pugh C whose average MELD score were 14.434±5.674,average ICGR15 were(48.720±12.712)﹪,average K value were (0.050±0.019)/min. There were significant statistical differences in K value, ICGR15 and MELD score in patients with different Child-Pugh groups (P<0.01).As the Child-Pugh classification of liver function gradually deterio -rated, the R15 and MELD score increased, while K value decreased. ICGR15 and K value are discrete in Child-Pugh A group, by contrast, are more centralized in Child-Pugh C group. Significant correlations were found between the parameters of the ICG test and Child-Pugh score,MELD score. Positive correlation was observed between R15 and Child-Pugh score,MELD score while a negative correlation was observed between K value and Child-Pugh score,MELD score. And compared with K value, ICGR15 showed better correlation.Multiple linear regression between the parameters of the ICG and conventional biochemical indicators were conducted.Correlation between ICG Rl5 and clinical markers (PTA,CHE)is significant,While correlation between K value and clinical markers (PTA,CHE,ALB)is significant.ICG test parameters was not statistically significant in patients with liver cirrhosis caused by different causes in Child-Pugh A and C group,while in Child-PughB group,statistically significant differences were found between the patients with cirrhosis of HBV,HCV and patients with alcoholic cirrhosis (P<0.05).In the same Child-Pugh grade, liver reserve function of patients with alcoholic cirrhosis was worse compared with viral cirrhosis,which was not consistent with the traditional idea.Along with the continuous aggravating liver fibrosis, liver stiffness value (LSM) and ICG R15 increase, while K value declined. The difference of ICG parameters (K value, ICGR15) between F1 and F4,F2 and F4,F3 and F4 were all significant(P<0.05). There was good correlafion between ICG parameters and LSM value.Different level of ICG before surgery,the incidence of ascites were all significant(P<0.05). As ICGR15 increased, the incidence of ascites increased. The proportion of moderate and severe ascites is higher.Conclusion: As the Child-Pugh classification of liverfunction gradually deteriorated, the ICGR15 and MELD score increased, while K value decreased. ICG test and clinical markers(ALB,CHE,PTA) could be used in evaluating liver reserve function. ICG test parameters was not statistically significant in patients with liver cirrhosis caused by different causes in Child-Pugh A and C group.While in Child-PughB group, statistically significant differences were found between the patients with alcoholic cirrhosis and patients with viral cirrhosis. In the same Child-Pugh grade,liver reserve function of patients with alcoholic cirrhosis was worse compared with viral cirrhosis,which was not consistent with the traditional idea. Along with the continuous aggravating liver fibrosis, LSM value and ICG R15 increase, while K value declined. Transition area between F3 and F4 is the point qualitative changed from compensated to decompensated period. As ICGR15 increased, the incidence of ascites after surgery increased.