Overview of fluorescence imaging focusing on fusion-image for laparoscopic hepatectomy

A fluorescence imaging using indocyanine green (ICG) as a fluorophore was first reported to be useful for assessing coronary artery bypass graft patency (1). The technique was subsequently used to visualize lymphatic vessels (2) and to identify sentinel lymph nodes during breast (3) and gastric (4) cancer surgeries. ICG is taken into the hepatocyte and solely excreted into the bile (5). The fluorescence imaging technique has been recently used for hepatobiliary surgery to identify hepatic cancers (6,7) the bile duct (8-10), and bile leakage (11,12) and to visualize portal venous and hepatic venous territories (13-16).