Biliary indocyanine green excretion as a predictor of hepatic adenosine triphosphate levels in patients with obstructive jaundice

BACKGROUND: Correlation of the hepatic adenosine triphosphate (ATP) level w ith indocyanine green (ICG) excretion into bile was examined in patients wi th obstructive jaundice after the relief of hyperbilirubinemia by preoperat ive percutaneous transhepatic biliary drainage (PTBD). METHODS: Patients with complete bile duct obstruction, the mean serum total bilirubin concentration being 13.6 +/- 8.5 (SD) mg/dL, underwent PTBD prio r to surgery, Within a few days before surgery when the mean serum total bi lirubin level decreased to 1.2 mg/dL, ICG (0.5 mg/kg) was intravenously inj ected, and the whole bile was collected at 1-hour intervals for 5 hours. Th e ICG concentration in bile, bile flow rate, amount of ICG excreted in bile , and biliary ICG excretion rate as percentage of the injected dose were de termined. At the time of surgery, a small liver tissue sample was obtained immediately after laparotomy without any ischemic procedures, and ATP conce ntrations were determined. Results of hepatic ATP levels were correlated wi th laboratory and clinical determinations. RESULTS: The bile flow rate was essentially constant during the 5-hour peri od, the mean value being 21 mL/hour. The ICG concentrations in bile gradual ly increased, reached the maximal level in 3 hour, and declined thereafter, The biliary ICG excretion rate for 5 hours was 40% +/- 18% of its injected dose, The biliary ICG excretion rate and amount of ICG excreted in bile fo r 5 hours significantly (P <0.05) correlated with the hepatic ATP level. Th e decline index of serum bilirubin during PTBD was also correlated with the hepatic ATP level. The serum ICG retention rate, bile flow rate, maximal I CG concentration in bile, and other liver function tests including serum al bumin and cholinesterase levels did not correlate with the hepatic ATP leve l. CONCLUSIONS: Both the amount of and excretion rate of ICG in bile reflect t he hepatic ATP level. Determination of biliary ICG excretion contributes to precise evaluation of hepatic energy status before surgery in patients wit h obstructive jaundice. Am J Surg. 2000;179:161-166. (C) 2000 by Excerpta M edica, Inc.