gms | German Medical Science

Objective: The aim was to investigate a) on an animal experiment whether multispectral fluorescence (MFL) as a new optical technique can enhance the visualization of the different phases of the blood-flow with simultaneous visualization of the anatomical structures, and b) applied to the operation theatre via the implementation on a surgical microscope to show if MFL can ergonomically enhance the surgical treatment of vascular malformations and highly vascularized tumors of the CNS, compared to the conventional ICG videoangiography.

Methods: For the animal experiments we used a total of 7 pigs. A digital imaging of the arterial perfusion, capillary transition and venous drainage of the anatomical structures of the surgical field was performed. Additionally, the blood flow was interrupted by placing a surgical clip to demonstrate the blockage of the blood flow. The visualization was performed in real time and in a combination of white light, standard fluorescence and multispectral fluorescence mode. The clinical testing included 40 patients with vascular malformations and highly vascularized tumors of the CNS. After intravenous application of 5mg/ml ICG, normal and pathologic blood vessels were intraoperatively visualized on the microscope’s monitor as well as through the microscope’s eye pieces.

Results: In the animal experiment the visualization of the anatomical structures of the surgical field and the blood-flow within its vessels under the overlapping of the ICG fluorescence onto the standard white light produced high resolution images. The occlusion of blood vessels with surgical clips demonstrated sufficiently the blockage of the ICG perfusion and tissue reperfusion after clip removal was also very well visible.

During all 40 surgical cases the overlapping of the white light image and the fluorescent image as well as the direct delivery of the combined image through the eye piece allowed for the simultaneous collection of anatomical and dynamic data from the surgical field, without interruption of the surgical workflow.

Conclusion: MFL was shown to be superior to the classic ICG videoangiography for the visualization of vascular structures. With the development of a new multispectral surgical microscope, the data delivered to the surgeon during the procedure are substantially enhanced, compared and the workflow is notably improved due to the simultaneous, precise and clear visualization of the blood flow and the surrounding structures.