Impact of indocyanine green angiography on local cerebral perfusion: preliminary experience with a combined laser-Doppler spectrophotometry system.

Question: What impact has the use of indocyanine green (ICG) angiography, which is a neurosurgical standard procedure in aneurysm surgery, on local cerebral cortex perfusion? Methods: We studied local cerebral perfusion using the novel non-invasive laser-Doppler spectrophotometry system „Oxygen-to-see (O2C)“ in three patients with incidental aneurysms of the middle cerebral artery. Capillary venous oxygenation (SO2), post-capillary venous filling pressures (rHb) and blood flow (flow) were measured in 7 mm tissue depth using a subdural fiber optic probe. The cortical measurement site corresponded to the supply te…