Factors influencing the indocyanine green (ICG) test: additional impact of acute cholestasis.
OBJECTIVE
The indocyanine green (ICG) test has been described as a useful tool for evaluation of liver function. The aim of this study was to investigate an additional effect of acute cholestasis on the result of the ICG-test.


METHODS
Three Patients with suspected obstructive jaundice after liver surgery or transplantation without any symptoms of liver insufficiency but disproportionate impaired ICG-test were selected for repetitive ICG-test measurement after endoscopic intervention. Additionally experiments in a rat model of short-term common bile duct ligation (BDL) were performed. ICG plasma disappearance rate (PDR) and ICG retention at 15 min (R15) were determined by pulse dye densitometry before and 30 and 60 min after BDL.


RESULTS
The impaired ICG-test in patients resolved directly after endoscopic treatment of proven obstructive jaundice. Correspondingly, in rat experiments BDL compared to sham operation caused a marked reduction in ICG-PDR by 75% (p<0.005) and an increase of ICG-R15 (p<0.005). No alterations in conventional histology and only slight elevations of bilirubin and ALT were observed.


CONCLUSIONS
Acute cholestasis might be one additional factor directly influencing the ICG-test. This should be taken into account for correct interpretation of the ICG-test in respective clinical situations.
Stockmann
Martin
M
General, Visceral, and Transplantation Surgery, University Hospital Charité, Berlin, Germany. martin.stockmann@charite.de
Malinowski
Maciej
M
Lock
Johan F
JF
Seehofer
Daniel
D
Neuhaus
Peter
P
D000368:Aged; D000818:Animals; D002779:Cholestasis / Q000150:complications / Q000175:diagnosis*; D004396:Coloring Agents; D004195:Disease Models, Animal; D006801:Humans; D007208:Indocyanine Green; D041781:Jaundice, Obstructive / Q000209:etiology*; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D051381:Rats; D017207:Rats, Sprague-Dawley; D012307:Risk Factors
D004396:Coloring Agents; D007208:Indocyanine Green