Confirmation of blood flow in the arteries around the aneurysm is crucial in aneurysm surgery. Although intraoperative fluorescence video angiography is useful for this purpose, the limited observation field under a microscope makes it difficult to confirm blood flow in the arteries behind the parent arteries or the aneurysm. We developed intraoperative endoscopic indocyanine green (ICG) video angiography to overcome this weak point of microscopic fluorescence video angiography, and used it in nine patients with cerebral aneurysms. During clip placement, the endoscope was inserted to confirm aneurysm occlusion. Then, fluorescence video angiography was performed to observe blood flow via the endoscope as well as the microscope. The blood flow in the perforating arteries was clearly demonstrated in all but one case in which the adequate placement of the endoscope was difficult because of the optic nerve. There was no complication related to the procedure.
In conclusion, the technic is very useful and facilitates intraoperative real-time assessment of patency of the perforating arteries behind parent arteries or aneurysms.