Case 3: A 62-year-old woman presented with progressive headache and vertigo and was diagnosed as having 2 aneurysms arising from right A2-anterior communicating artery junction, one projecting anteroinferiorly and the other projecting medially []. After clipping of the first aneurysm, micro-Doppler examination detected no flow in the aneurysm. The arterial phase in the ICG-VA also showed lack of flow into the aneurysm and normal flow in the nearby perforating artery. However, the venous phase showed a glimmer of fluorescence visible in the aneurysm sac [], suggestive of residual filling of the aneurysm. The corresponding color map showed a portion of the aneurysm with blue color and a delayed ascending curve (purple color) was detected in the intensity [Figure and ], thus confirming a residual aneurysm. The clip was then readjusted and ICG-VA was repeated. This time it showed complete absence of flow within the aneurysm. A postoperative 3D-CTA demonstrated complete obliteration of the aneurysm.
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.