Potential of indocyanine green near-infrared fluorescence imaging in experimental and clinical practice.

Background: Visualization of Indocyanine Green (ICG) near-infrared (NIR) fluorescence is a promising technique for biomedical applications because of its deep tissue penetration, low autofluorescence, weak dependence on ambient light, safety for patients and medical staff.

Methods: To apply this technique to animal studies and clinical practice, we developed multispectral NIR fluorescence imaging system FLUM-808, which can be used in experimental studies and clinical practice, in open and endoscopic surgery (fluorescence-guided surgery). The object is illuminated either directly or through an illumination channel depending on what optical instrument is used (camera lens, fiber endoscope, rigid endoscope, surgical microscope, etc.). The system is able to simultaneously display NIR images and images captured under white light.

Results: This article provides examples of imaging techniques used during open and endoscopic surgery with ICG as an NIR fluorescent dye and photosensitizer, demonstrates applications of the technique for experimental and clinical purposes: for intraoperative imaging of blood and lymphatic vessels; for detection of tumors and sentinel lymph nodes; for assessment of tissue, organ, or anastomotic blood supply.

Conclusions: This method significantly helps to accurately assign the areas of increased fluorescence to certain anatomical structures during surgery. NIR fluorescence diagnosis can be used in important experimental studies and in clinical practice. The described results of ICG studies can help in developing new fluorescence-based diagnostic and theranostic approaches employing more effective exogenous fluorophores and photosensitizers.