Quantitative assessment of hepatic function by indocyanine green clearance test

Abstract

The purpose of the investigation was to study the informative and prognostic values of a dynamic hepatic function test using indocyanine green (ICG) in cirrhotic patients. The investigation covered 149 patients with hepatic cirrhosis (a study group) and 20 patients without signs of liver disease (a control group). The plasma ICG elimination rate (PICGER) was significantly lower in the study group (7.6±3.4 and 22.9±4.2% per min in the study and control groups, respectively; p < 0.001). With the progression of hepatocellular dysfunction revealed by the ChildPugh criteria, the indocyanine clearance values became progressively worse. In cirrhotic patients, PICGER correlated with the levels of total bilirubin (r = -0.501; p < 0.001), albumin (r = 0.494; p < 0.001), international normalized ratio (r = 0.475; p < 0.001), and the histological activity index of the necroinflammatory process in the hepatic parenchyma (r =-0.579; p < 0.001). In these patients, median survival was significantly higher in cases with prompter ICG elimination and, at a PICGER of > 7, 5 to 7, and <5% per min, it was 20, 11.5, and 6 months (χ2 = 51.9; p<0,001). Analysis of ROC curves demonstrated a greater prognostic value of the ICG clearance test than the Child-Pugh and MELD criteria (statisticPER, 0.852±0.032; c-statisticCHILD, 0.767±0.039, с-statisticMELD, 0.758±0.041; p < 0.001). The sensitivity and specificity of the clearance test in the prediction of annual survival were 86.5 and 76.8%, respectively. Thus, the determination of ICG clearance is a highly informative and specific dynamic test that estimates hepatic functional reserves. The inclusion of this criterion into the existing scales for rating the severity of hepatocellular dysfunction permits improvement of the diagnostic and prognostic efficiency of their use.

Keywords

• hepatic functional reserves
• clearance test
• indocyanine green
• hepatic cirrhosis
• child-pugh scale