Fig. 1

a–f Sequential intraoperative view of the left ACM resection through a left FTOZ approach. a Extradural bone drilling of the sphenoid ridge, the posterior orbital roof, and the optic canal roof exposing the ACP between the superior orbital fissure (SOF) and the falciform ligament (FL) covering the optic nerve. b Removal of the ACP tip (shark tooth). c The optic strut is drilled out exposing the Dolenc triangle (Dolenc T.). d The tumor was extending in the optic canal beyond the falciform ligament; optic nerve decompression was done by releasing the falciform ligament and tumor debulking with care not to compromise any vascular supply to the undersurface of the optic nerve. e, f Encasement of the internal carotid artery (ICA) and middle cerebral artery (MCA) by the tumor, careful dissection of the tumor aided by mobilization of the ICA through releasing the distal dural ring (DDR)