title: Extradural endoscope-assisted subtemporal posterior clinoidectomy: a cadaver investigation study.
abstract: BACKGROUND
  Surgical treatment of distal basilar artery aneurysms is challenging because of the narrow surgical corridor, presence of vital perforating vessels, deep location, and difficulty in obtaining proximal control.
  
  
  OBJECTIVE
  To investigate using a cadaver model the feasibility of performing a transcranial extradural posterior clinoidectomy via a subtemporal route between V2 and V3 using an endoscope-microscope combination.
  
  
  METHODS
  Fourteen dissections were performed in 14 fresh cadaver heads. A standard pterional approach with removal of the zygomatic arch was followed by a 2-stage dissection to remove the posterior clinoid process. In stage 1 (microscopic stage), the area between the second and third trigeminal divisions (V2 and V3) was exposed and the anterior half of the bone between them was drilled to the sphenoid sinus cavity inferior to the carotid sulcus. In stage 2 (endoscopic stage), the drilling was continued to the carotid sulcus. Next, the endosteal layer of the dura lining the carotid sulcus was dissected from the bone that was then removed. At the end of this stage, the dura reflection that forms the posterior part of the pituitary capsule was exposed and the base of the posterior clinoid process was removed using a high-speed drill and curet. Finally, the dura was opened to confirm the removal of the posterior clinoid process.
  
  
  RESULTS
  It was possible to remove the posterior clinoid process in every specimen without any obvious anatomic injury to the surrounding structures.
  
  
  CONCLUSIONS
  This study demonstrated the feasibility of the resection of the posterior clinoid process extradurally. This maneuver could be incorporated in multiple cranial base approaches to the retrosellar area and interpeduncular cistern region.
authors.affiliation: Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, The Ohio State University Medical Center, Columbus, Ohio 43210, USA. asem.salma@osumc.edu
authors.forename: Asem
authors.initials: A
authors.lastname: Salma
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.forename: Mario
authors.initials: M
authors.lastname: Ammirati
mesh_terms: D002102:Cadaver; D003388:Cranial Fossa, Posterior / Q000601:surgery*; D003399:Craniotomy / Q000379:methods*; D004388:Dura Mater / Q000601:surgery; D004724:Endoscopy / Q000379:methods*; D006801:Humans; D008866:Microsurgery / Q000379:methods*