Real-Time Overlapping of Indocyanine Green—Video Angiography With White Light Imaging for Vascular Neurosurgery: Technique, Implementation, and Clinical Experience

Abstract

BACKGROUND Fluorescent-guided techniques in vascular neurosurgery can be demonstrated via black and white indocyanine green videoangiography (ICG-VA). Multispectral imaging (MFL) is a new method, which overlaps fluorescence with the white light and provides a fluorescent white light augmented reality image to the surgeon. OBJECTIVE To investigate (a) whether MFL can enhance the visualization of the blood-flow with simultaneous visualization of the anatomic structures and (b) if MFL can ergonomically improve the microvascular surgical treatment compared to ICG-VA. METHODS A digital imaging of the blood flow after intravenous injection of ICG on 7 pigs was performed in real time under white light, standard fluorescence, and MFL. The blood flow was interrupted with a surgical clip, demonstrating the blockage of the blood flow. We prospectively included 30 patients with vascular deformities. The vasculature was visualized on the microscope's monitor and through the microscope's eyepiece. RESULTS In the animal experiment, the visualization of the anatomy and the blood flow under MFL produced high resolution images. The occlusion of blood vessels demonstrated sufficiently the blockage of tissue perfusion and its reperfusion after clip removal. During all 30 surgical cases, the MFL technique and the direct delivery of the pseudo-colored image through the eyepiece allowed for enhanced anatomic and dynamic data. CONCLUSION MFL was shown to be superior to the classic ICG-VA, delivering enhanced data and notably improving the workflow due to the simultaneous and precise white light visualization of the blood flow and the surrounding anatomic structures.

5-Aminolevulinic Acid Multispectral Imaging for the Fluorescence-Guided Resection of Brain Tumors: A Prospective Observational Study

“…Therefore, s it is crucial to address well-evaluated and documented disadvantages of 5-ALA regarding operation ergonomics and bleeding complications. The described novel MFL technology is able to bring light back to the operating field during the 5-ALA guided surgery, similarly to what we have previously described for fluorescence guided surgery using other fluorophores like ICG even for vascular pathologies (15) or brain tumor treatment (16). For that matter, the presented real time augmented reality setting combined with a commercially available microscope could be a promising tool to improve surgical therapy.…”

“…Furthermore, previously to this study we made the observation that this mode is able to sufficiently differentiate between the brain's physiological color and the artificial color chosen (15). This led us to believe that in the clinical setting of tumor surgery it would be easier to identify and resect tumor tissue in this augmented reality setting as opposed to operation under blue light were brain tissue is pretty much dark.…”

“…To do so, the multispectral fluorescence microscopy (MFL) was incorporated into a commercially available microscope (ARveo, Leica Microsystems, Wetzlar, Germany). We have already investigated its use for the combination of indocyanine green (ICG) fluorescence and white light images in the therapy of vascular anomalies of the brain in both an animal model, and on a human cadaver model as well as in clinical use for vascular and tumor applications ( 15 – 17 ). Such a microscope also allows simultaneous visualization of PpIX fluorescence and white light.…”

5-Aminolevulinic Acid-Induced Porphyrin Contents in Various Brain Tumors: Implications Regarding Imaging Device Design and Their Validation

“…Because PPIX fluoresces in the visible range at 635 nm, no camera system or image processing technologies are required for seeing fluorescence. Recently developed technologies use different filters for improved background visualization 2 or rely on camera systems and image processing for producing an image, eg, the ORBEYE (Olympus, Tokyo, Japan) system. 3 However, it should be assumed that novel technology performs comparably to the established standard tested in a randomized setting.…”