title: Anatomic study of the anterior skull base via an endoscopic transnasal approach.
abstract: OBJECTIVE
  With rapid advances in endoscopic neurosurgery, it has become possible to treat some lesions located in the anterior skull base through a transnasal approach. This anatomic study was undertaken to describe the area of surgical exposure of the anterior skull base afforded by transnasal approaches with an endoscope, as well as to provide references for clinical practice.
  
  
  METHODS
  Thirty bony skull base specimens (all Chinese) were used, and 10 injected adult cadaver heads (all Chinese) were dissected for a simulated endoscopic transnasal approach to the anterior skull base. The distance between the bilateral optic canals was measured in skull base specimens and the distance between the columella and anterior ethmoid artery or posterior ethmoid artery was measured on both sides in adult cadaver heads.
  
  
  RESULTS
  The optic canals were 15.13±1.69 mm apart. The distance between the columella and posterior ethmoid artery was 71.01±3.99 mm on the left side and 72.27±3.97 mm on the right side. The distance between the columella and anterior ethmoid artery was 64.811±3.74 mm on the left side and 64.18±3.74 mm on the right side. The endoscopic transnasal approach to the anterior skull base exposed the optic protuberance, sellar floor, crista galli, anterior ethmoid artery, and posterior ethmoid artery. In addition, bilateral olfactory bulbs, olfactory tracts, and optic nerves beneath the dura mater were also revealed.
  
  
  CONCLUSIONS
  The anatomic data as well as established anatomic landmarks associated with endoscopic surgery would benefit clinical practice.
authors.affiliation: Beijing Fuxing Hospital Affiliated With Capital Medical University, Beijing, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Song
authors.forename: Xuyi
authors.initials: X
authors.lastname: Zong
authors.forename: Xinsheng
authors.initials: X
authors.lastname: Wang
authors.forename: Ao
authors.initials: A
authors.lastname: Pei
authors.forename: Peng
authors.initials: P
authors.lastname: Zhao
authors.forename: Songbai
authors.initials: S
authors.lastname: Gui
authors.forename: Yaohua
authors.initials: Y
authors.lastname: Yan
authors.forename: Yazhuo
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000328:Adult; D002102:Cadaver; D002536:Cerebral Arteries / Q000033:anatomy & histology; D004724:Endoscopy / Q000379:methods*; D005004:Ethmoid Bone / Q000601:surgery; D005005:Ethmoid Sinus / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008297:Male; D009092:Mucous Membrane / Q000033:anatomy & histology; D009296:Nasal Cavity / Q000033:anatomy & histology* / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000379:methods*; D019291:Skull Base / Q000033:anatomy & histology*; D013101:Sphenoid Sinus / Q000033:anatomy & histology; D013355:Subdural Space / Q000033:anatomy & histology; D016707:Tissue Fixation; D014795:Visual Pathways / Q000033:anatomy & histology