Intraoperative fluorescent imaging using indocyanine green for liver mapping and cholangiography.

Background: Preoperative imaging is widely used and extremely helpful in hepatobiliary surgery. However, transfer of preoperative data to a intraoperative situation is very difficult. Surgeons need intraoperative anatomical information using imaging data for safe and precise operation in the field of hepatobiliary surgery. We have developed a new system for mapping liver segments and cholangiograms using intraoperative indocyanine green (ICG) fluorescence under infrared light observation.
Method: The imaging technique for mapping liver segments and cholangiogram based on ICG fluorescence used an infrared-based navigation system. Eighty one patients with liver tumors underwent hepatectomy from 2006, January to 2009, March. In liver surgery, 1 ml of ICG was injected via the portal vein under observation by the fluorescent imaging system. Fourteen patients were underwent laparoscopic cholecystectomy for chronic cholecystitis with gallstones. In laparoscopic cholecystectomy, 5 ml of ICG was administered intravenously just before operation and the bile duct was observed using the infrared-based navigation system.
Result: This new technique successfully identified stained subsegments and segments of the liver in 73 of 81 patients (90.1%). Moreover, clear mapping of liver segments was obtained even against a background of liver cirrhosis. Fluorescent cholangiography clearly showed the common bile duct and cystic duct in 10 of 14 patients (71.4%). No adverse reactions to the ICG were encountered.
Conclusion: Application of this technique allows intraoperative identification of anatomical landmark in hepatobiliary surgery.