The supraorbital keyhole approach effectively exposes the frontal lobe base, anterior clinoid process, canalis opticus, olfactory sulcus, olfactory tract, optic nerve, optic chiasm, oculomotor nerve, anterior communicating artery, anterior cerebral artery A1 segment, pituitary stalk, diaphragma sellae, dorsum sellae, posterior clinoid process
, basilar artery apex, posterior cerebral artery P1 segment, superior cerebellar artery proximal, front upper pontine and interpeduncular cistern, anteromedial temporal lobe, internal carotid, middle cerebral artery (M1, M2 segment, and part of M3 segment), anterior choroidal artery, posterior communicating artery; and contralateral carotid artery medial surface, anterior cerebral artery A1 and A2 proximal, middle cerebral artery M1 and M2 proximal.
Posterior clinoid process
was normal in all the cases.
In relation to the basilar tip aneurysms, sometimes, trough the posterior part of the superior wall is necessary drilling out the posterior clinoid process to approach the basilar aneurysm neck when it is hidden behind the dorsum sellae (31,32,33).
After the dura has been incised over the area previously occupied by the anterior clinoid process, the surgeon's attention is focused posteriorly, on the region of the posterior clinoid process where the third nerve enters the dura.
The posterior clinoid process must be drilling to permit proximal control in basilar artery aneurysm in a low basilar artery bifurcation, that is hidden by the posterior clinoid process (31,32,33,34) or lesions localized anteriorlly to the upper pons or upper prepontine cistern (34).
Its posterior border is marked by the petroclinoidal (petrosphenoidal or Gruber's) ligament extending between the petrous apex and posterior clinoid process
of the sphenoid.
Unlike the anterior clinoid process, the posterior clinoid process has received less attention in past research studies.
The anterior edge of the pituitary fossa is completed laterally by the middle clinoid process and the posterior boundary is formed by the dorsum sellae, the superolateral angles of which are expanded to form the posterior clinoid process (1).
A spinner dolphin, Stenella longirostris, from the Gulf of Mexico has both an anterior and a posterior clinoid process
bordering its sella turcica.