Fluorescence-guided hepatobiliary surgery with long and short wavelength fluorophores
Fluorescence-guided surgery (FGS) is a potentially powerful tool for hepatobiliary (HPB) surgery. There are a number of FDA approved fluorophores used in surgery such as methylene blue (MB), 5-aminolevulinic acid (5-ALA), and indocyanine green (ICG). ICG is currently the most commonly used fluorophore for fluorescence-guided HPB surgery due to its biliary excretion mechanisms, improved tissue depth penetration and wide availability of devices equipped to image 800 nm. ICG has been used to visualize the biliary tree, identify biliary leaks, outline anatomic hepatic segments, identify tumors, and evaluate perfusion and graft function in liver transplants. The high sensitivity of fluorescence navigation is especially useful in minimally invasive settings where tactile feedback is limited. These fluorescent probes have been widely used in oncologic procedures, but they are not cancer specific. Specificity can be obtained by using tumor-targeting fluorescent probes. While most of these probes are still under pre-clinical development, the results have been promising. FGS with tumor-specific probes can have a positive impact on outcomes of HPB surgery.