Speaker:  Prof. Takeaki Ishizawa, M.D., Ph.D., F.A.C.S. - Department of Hepatobiliary-Pancreatic Surgery, Graduate School of Medicine, Osaka Metropolitan University.

Abstract: Intraoperative fluorescence imaging using indocyanine green (ICG) has become used widely for real-time visualization of biological structures and assessment of blood perfusion. I herein demonstrate development history and clinical applications of ICG-fluorescence imaging to HBP surgery. 1) Fluorescence cholangiography: fluorescence images of the extrahepatic bile ducts can be obtained by intrabiliary injection of ICG solution (0.025 mg/mL) or preoperative intravenous injection (IV) of ICG (2.5 mg). The latter technique begins to be used worldwide for confirmation of the bile duct anatomy during minimally-invasive cholecystectomy. 2) Identification of hepatic tumors: IV-injected ICG (0.5 mg/kg) accumulates in hepatocellular carcinoma tissues and in non-cancerous hepatic parenchyma surrounding liver metastasis, which can be used for intraoperative identification of subcapsular hepatic tumors by fluorescence imaging. 3) Hepatic segmentation: ICG solution (0.25 mg in 5 mL indigo-carmine solution) is injected into a tumor-bearing portal branch under ultrasound guidance (positive staining technique). ICG can also be administered intravenously following closure of a corresponding portal pedicle (negative staining technique). These techniques enable long-lasting delineations of segmental boundaries throughout hepatectomy procedures because ICG retains in hepatocytes for more than 5 hours. 4) Assessment of blood perfusion: fluorescence imaging following intraoperative bolus IV ICG (2.5mg) visualizes arterial/portal blood flows and perfusions to the surrounding organs during surgeries with resection/reconstruction of major vessels.
Along with current dissemination of ICG-fluorescence imaging, novel target-specific fluorophores and imaging devices are being developed actively. Our approach is to use enzyme-activatable fluorophores for real-time visualization of cancerous tissues and leaking pancreatic juice. The fluorescence imaging techniques will develop into an indispensable intraoperative navigation tool, enhancing safety and curability of HBP surgery.

Host: 

Dr. Itxarone Bilbao, Hepatobiliopancreatic surgery and transplants, Children's Hospital and Woman's Hospital.

Dr. Concepción Gómez, Main researcher -Hepato-bilio-pancreatic surgery (HBP) and liver transplantation.