*2.2.2 Role of indocyanine green (ICG)*

Indocyanine green video angiography (ICG-VA) is used in intracranial bypass surgery which is a non-invasive technique to assess the patency of a bypass graft or anastomosis [34–36]. ICG is a preservative-free powder (25 mg), which is diluted with 10 ml of distilled water (2.5 mg/ml). The technique requires intravenous injection of ICG and the direct application of a microscope with an integrated ICG camera on the operative field. The standard dose range from 5 to 25 mg. Intraoperative ICG-VA facilitates the identification of potential recipient vessels and detection of pathological flow patterns [35]. The main disadvantage of ICG angiogram is the failure to visualize deeper vasculatures. ICG injection may cause erroneous readings on the pulse oximeter and can cause anaphylactic reactions [37, 38].

*Perioperative Considerations for Revascularization and Non-Revascularization Surgeries… DOI: http://dx.doi.org/10.5772/intechopen.96564*
