Indocyanine green retention test in cirrhosis and portal hypertension: Accuracy and relation to severity of disease

BACKGROUND & AIMS: Patients with cirrhosis and portal hypertension often develop complications relating to hepatic excretory dysfunction. The standard measurement of the hepatic excretion is the constant infusion indocyanine green clearance (ICGCI ) technique. The ICG 15-minutes retention test (ICG-r15) is faster, more patient friendly and cheaper. The aims were to compare the ICG-r15 test with the standard method, to assess relations to patient characteristics and survival, and to assess the ICG-r15 level in healthy control subjects.

METHODS: We included 68 patients with cirrhosis and portal hypertension (Child class A/B/C:17/37/14). All patients underwent a full liver vein catheterization and hemodynamic evaluation with determination of ICG-r15 and ICGCI as the reference in a subset of 38 patients. Sixteen healthy controls subjects were included for compiling a reference interval.

RESULTS: The ICG-r15 was increased in the cirrhotic patients with increasing values in parallel with liver dysfunction (15/41/58%) in Child class A/B/C compared with 7% in the controls (p<0.001). ICG-r-15 correlated highly significantly with the ICGCI (r=-0.96, p<0.0001) and in a multivariate regression analysis with HVPG, markers of liver dysfunction and hyperdynamic circulation (p<0.05-0.005). In the control group normal reference values ranged from 0-13%. In addition ICG-r15 was significantly related to mortality in the patient group (p=0.02).

CONCLUSIONS: ICG-r15 reflects portal hypertension, the degree of hepatic failure, and survival and may replace the standard ICGCI . A more elaborated reference interval needs to be compiled and the prognostic value of ICG-r15 should be validated.