Intraoperative Fluorescence

Indocyanine green (ICG) is a substance that fluoresces when illuminated with light with a near infrared spectrum (750–810 nm). Protein binding can be visualized through tissues up to 1 cm thick. Used for various diagnostic imaging, cardiology, and ophthalmology methods, indocyanine green fluorescence is also used clinically in the surgical and hepatobiliary-pancreatic fields .

The method consists of an intravenous injection of this contrast. In the operating room, using special light sources, the contrast allows a better identification of the structures guiding the surgeon in the dissection, with applicability in open surgery, videolaparoscopy, and robotic surgery.

ICG is actively secreted into bile or can be injected directly into the biliary system, resulting in ICG fluorescence cholangiography. In addition, intravenous ICG allows the identification of benign and malignant liver lesions (hepatocellular carcinomas, colorectal, and pancreatic metastases) with different fluorescence patterns related to the different characteristics of the tumor and peritumoral tissue, hence its application as a guide for disease resections. hepatica (Figure 1). The selective injection of ICG at the level of certain portal branches (or the ligation of the latter by intravenous ICG) allows the demarcation of individual liver segments, enabling at least invasive segmental liver resections in subjects affected by cirrhosis in conditions of reduced liver function.