Intra-Operative Vascular Fluorescence for Neurosurgery

A new intra-operative video angiography system offers quick and easy visualization of blood flow in the cerebral vascular area by using indocyanine green (ICG).

The FL800 fluorescence system is designed to assist surgeons in the visualization of blood flow during surgery. It is a combination of a surgical microscope, an excitation light system, an ICG fluorescent agent, and a near infra-red (NIR) camera. To change from white light to NIR mode, the surgeon simply pushes a button found on the pistol grip of the surgical microscope.

The vascular fluorescence procedure is begun by injecting the ICG agent intravenously. The surgeon then presses one button, operating the special NIR camera that picks up the ICG fluorescence sequence and shows it on the video monitor, through the microscope eyepieces, or both. The system also records the imaging as a special loop so the surgeon can repeat the image later in surgery. This procedure can be repeated up to six times in a single surgery so that the surgeon can track the effects of his surgical procedure on blood flow in the brain.

The perfusion of the ICG is detectable because ICG excites around 800 nm light and then emits fluorescence at 835 nm. This 835 nm light is filtered away from the normal white light and picked up by the NIR charged-couple device (CCD) camera. The CCD camera converts the 835 nm light (invisible to the human eye) to white light.

The FL800 is the product of Leica Microsystems (Wetzlar, Germany) and has been approved by the U.S. Food and Drug Administration (FDA) for use with the ICG solution supplied by Akorn (Buffalo Grove, IL, USA).

ICG angiography is predominantly used in diagnostic studies for observation of retinal and choroidal vasculatures. It is generally used in evaluating retinal neovascularization, serous detachment of retinal pigment epithelium, hemorrhagic detachment of retinal pigment epithelium, and retinal hemorrhage.



Related Links:
Leica Microsystems
Akorn