File:Bony and dural resection for paraclinoid aneurysm surgery.jpg

(A) Extradural bone exposure (schematic) includes a frontotemporal craniotomy (hatched area 1) along with resection of the sphenoid ridge, posterior orbital roof, and medial floor of the superior orbital fissure (SOF) (hatched area 2). Intradural bone removal includes resection of the remaining medial sphenoid wing and drilling of the anterior clinoid process (ACP) and optic strut (OS) (area 3). (B) Clinoid dural opening (schematic). The dashed lines represent the dural incisions used during intradural anterior clinoidectomy. The incision is extended through the falciform ligament and optic nerve (ON) ensheathment to decompress and mobilize the ON as needed. (C) Exposure following intradural ACP removal and drilling of the OS (schematic). Aneurysms arising from the clinoidal segment (ClinSeg) and ophthalmic segment (OphSeg) of the internal carotid artery (ICA) are well accessed through this approach. (D) Operative view—clinoidal segment. Opening of the carotid-oculomotor membrane (COM) between the clinoidal segment and the oculomotor nerve (III) provides excellent exposure of the anterior genu of the cavernous ICA segment. DR, Dural ring; OphArt, ophthalmic artery; PComArt, posterior communicating artery.