title: [Extradural en bloc removal and in situ replacement of the anterior clinoid process].
abstract: Extradural removal of the anterior clinoid process (ACP) is useful and essential for approaching aneurysmal and tumor lesions in and around the cavernous sinus. A safe, rapid and less invasive technique is beneficial for this basic skull base surgery. We developed a new technique by sharply cutting the ACP together with the part of the sphenoid ridge bone followed by complete replacement. A series of patients with either basilar top or internal carotid artery aneurysms underwent the present technique. After frontotemporal craniotomy, the lateral frontal and anterior middle cranial fossae are exposed extradurally. The bone was cut using a cutting steel burr from the sphenoid ridge to the superior orbital fissure and to the optic canal. By sharply separating the meningo-orbital band between the dura propria and the periorbital fascia, the ACP is exposed. The cutting burr runs underneath the ACP. By leaving a very thin sheet of bone, the entire bone piece was elevated after fracturing the thin bone using a chisel. By severing the carotid ring, the internal carotid artery is freed and mobile either laterally or medially to obtain an ample basal cistern. After operation, the once removed clinoid process is replaced in situ using a titanium plate screw. Extradural en bloc removal and in situ replacement of the ACP can be safely done by this cutting procedure. This can provide a good cosmetic result without causing enophthalmos or transient oculomotor palsy.
authors.affiliation: Department of Neurosurgery, Kanto Rosai Hospital, 1-1 Kizuki Sumiyoshicho, Nakahara, Kawasaki, Kanagawa 211-8510, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Shigeno
authors.forename: Junichiro
authors.initials: J
authors.lastname: Kumai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Horikawa
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Naemura
authors.forename: Kouki
authors.initials: K
authors.lastname: Aihara
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishikawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Nishido
authors.forename: Masaki
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Soichi
authors.initials: S
authors.lastname: Oya
authors.forename: Masaru
authors.initials: M
authors.lastname: Endo
mesh_terms: D001860:Bone Plates; D001863:Bone Screws; D003399:Craniotomy / Q000379:methods; D006801:Humans; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D019635:Neurosurgical Procedures / Q000379:methods*; D019651:Plastic Surgery Procedures / Q000379:methods*; D019291:Skull Base / Q000601:surgery; D013100:Sphenoid Bone / Q000601:surgery*; D014025:Titanium
chemical_list: D014025:Titanium