Clinical aspects of indocyanine green pharmacokinetics following portal vein administration

Abstract

This study was performed to demonstrate that measurement of the clearance of indocyanine green (ICG) following portal vein administration (CLpv) is more useful than that following peripheral vein administration (CLiv) for evaluating intrinsic clearance and hepatic blood flow. Eight patients, aged 55.9 +/- 8.8 years, who underwent partial hepatectomy were studied. ICG was administrated to all patients via peripheral and portal veins before and after enflurane anaesthesia and soon after surgery. ICG concentrations were measured by h.p.l.c. Non-compartmental analysis was applied to the ICG time-concentration data obtained. The area under the curve (AUC), clearance (CL), mean residence time (MRT) and volume of distribution (V) were calculated using this method of analysis. CLpv was significantly decreased from 26.4 +/- 13.2 ml kg(-1) min(-1) before anaesthesia, to 19.5 +/- 7.0 (P < 0.05) and 12.7 +/- 5.3 (P < 0.01) ml kg(-1) min(-1), respectively, during anaesthesia and after partial hepatectomy; These values were 72.1% (P < 0.01) and 48.5% (P < 0.01) of that observed at percutaneous transhepatic portography (PTP). CLiv was significantly decreased from 14.6 +/- 5.3 ml kg(-1) min(-1) before anaesthesia, to 9.4 +/- 3.6 (P < 0.05) and 9.8 +/- 4.1 (P < 0.05) ml kg(-1) min(-1), respectively, after partial hepatectomy and 12 h after operation; These values were 68.9% (P < 0.05) and 73.5% (P < 0.05) of the value at PTP. The other pharmacokinetic parameters examined, V and MRT, did not change significantly during anaesthesia or after surgery. The clearance of ICG after portal administration was useful for estimating hepatic blood flow and intrinsic clearance in perioperative management of liver surgery.