Case 2: A 53-year-old woman presented with recurrent severe headache. She was found to have 2 aneurysms located in the right middle cerebral artery []. Following complete microsurgical dissection of the aneurysms, parent vessels and their branches, intraoperative ICG-VA was performed. The blood flow in the aneurysms and the MCA branches was clearly observed before clip application. After clipping of the proximal aneurysm, ICG-VA was repeated to confirm the exclusion of the aneurysm and to detect any residual blood flow in the clipped aneurysm. However, due to the repeated injections of ICG within a short interval, the originally injected volume was still detectable in the aneurysm []. Hence it was difficult to confirm the occlusion of aneurysm on the basis of simple ICG-VA. To clear this dilemma, the intensity diagram function integrated into the surgical microscope was used to check the variation in the blood flow of clipped aneurysm over time. The curve of the aneurysm had no obvious upslope, which implied complete obliteration on the color map [Figure and ]. Therefore, no readjustment was warranted and we left the clips in place based on this finding. Later, the complete obliteration of the aneurysm was re-confirmed by postoperative 3D-CTA examination obtained 2 days after surgery.
A 51-year-old woman who experienced massive intraventricular hemorrhage due to presence of a post-central parasagittal AVM, Spetzler & Martin grade 3, underwent surgery (Figures and ). In this case, we performed right frontoparietal craniotomy and approached the AVM via right interhemispheric route (). However, through the delay map, visualization of the precise structure of the AVM was not possible due to depth of the nidus and angle of the surgical approach (); moreover, due to swelling of the brain, exposure of the AVM was unstable.