Comparison of bolus and infusion methods for estimating hepatic blood flow in patients with liver disease using indocyanine green

A non-invasive method of estimating liver blood flow by a two-compartment pharmacokinetic model of the plasma clearance of indocyanine green has been previously described in normal animals and patients without liver disease. This non-invasive technique has been compared with the conventional method of measuring liver blood flow by hepatic vein catheterisation in 25 patients with liver disease. There was good correlation between the values for indocyanine green clearance, with the infusion method tending to produce slightly higher results. However, there was poor agreement in the measurement of liver blood flow, as the non-invasive technique over-estimated the hepatic extraction ratio and thus underestimated liver blood flow. Therefore, in patients with liver disease the non-invasive method cannot be relied upon or replace hepatic vein catheterisation for the measurement of liver blood flow.