[Three patients with Gilbert's syndrome associated with constitutional excretory defect of indocyanine green]

We routinely perform, as a preoperative liver function test, the indocyanin green (ICG) test in patients scheduled for operations under general anesthesia. Doubts have been raised, however, concerning the necessity for this test, since no abnormalities have ever been detected by it. Nonetheless, we noted a high level of ICG retention and a slight increase in indirect bilirubin in 3 patients, and further investigation led to a diagnosis of Gilbert's syndrome accompanied by constitutional impairment of ICG excretion. This syndrome can be associated with perioperative jaundice in patients with malnutrition and those who received halothane, morphine, or some other agents. Although the indirect bilirubin level increased briefly after surgery, no other abnormalities occurred in the 3 patients. Since this syndrome is asymptomatic and is detected incidentally, the preoperative ICG test was considered to be useful.