FIG 6. Patient with a right internal carotid artery aneurysm.

A, 3D-CTA (superior view) reveals the fronto-orbital vein (white arrow) emptying into the SPS at the inner portion of the sphenoid wing (black arrow) A white arrowhead indicates the SSVs.

B, A microscopic operative photograph shows that the right frontal lobe was retracted by the spatula to expose the right internal carotid artery (C). The aneurysm (white arrow) was barely clipped, although the bridging vein between the fronto-orbital vein and the SPS (black arrows) limited retraction of the frontal lobe. The black arrowhead indicates the draining point of this bridging vein into the SPS. The white arrowhead indicates the SSVs.