CLINICAL ASPECTS OF INDOCYANINE GREEN PHARMACOKINETICS FOLLOWING PORTAL-VEIN ADMINISTRATION

Aims This study was performed to demonstrate that measurement of the c learance of indocyanine green (ICG) following portal vein administrati on (CLpv) is more useful than that following peripheral vein administr ation (CLiv) for evaluating intrinsic clearance and hepatic blood flow . Methods Eight patients, aged 55.9+/-8.8 years, who underwent partial hepatectomy were studied. ICG was administrated to all patients via p eripheral and portal veins before and after enflurane anaesthesia and soon after surgery. ICG concentrations were measured by h.p.l.c. Non-c ompartmental analysis was applied to the ICG time-concentration data o btained. The area under the curve (AUG), clearance (CL), mean residenc e time (MRT) and volume of distribution (V) were calculated using this method of analysis. Results 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 hepat ectomy 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 paramete rs examined, V and MRT, did not change significantly during anaesthesi a or after surgery. Conclusion The clearance of ICG after portal admin istration was useful for estimating hepatic blood flow and intrinsic c learance in perioperative management of liver surgery.