title: Cochlear line: a novel landmark for hearing preservation using the anterior petrosal approach.
abstract: OBJECTIVE
  The goal of this study was to develop a practical landmark for the safe and easy identification of the cochlea when performing anterior petrosectomy based on cadaver dissection results.
  
  
  METHODS
  The cochlear line was defined as the line drawn from the crossing point between the greater superficial petrosal nerve (GSPN) and the petrous internal carotid artery to the line drawn over the apex of the superior circumference of the dura of the internal auditory canal at a right angle. The validity of the cochlear line marking the anteromedial perimeter of the cochlea at the angle of the GSPN and the internal acoustic canal as a practical landmark were evaluated using 5 cadaver heads.
  
  
  RESULTS
  The mean distance (± SD) measured from the cochlear line to the margin of the cochlear cavity was 2.25 ± 0.51 mm (range 1.50-3.00 mm).
  
  
  CONCLUSIONS
  Anterior petrosectomy can be performed more efficiently by using the cochlear line as a key landmark to preserve the cochlea.
authors: Departments of 1 Neurosurgery and.
authors: Seong Min
authors: SM
authors: Kim
authors: Otorhinolaryngology, Eulji University Medical Center, Eulji University, Daejeon;
authors: Ho Yun
authors: HY
authors: Lee
authors: Department of Neurosurgery, Kosin University Gospel Hospital, Kosin University, Busan, Korea; and.
authors: Han Kyu
authors: HK
authors: Kim
authors: Barrow Neurosurgical Associates, Phoenix, Arizona.
authors: Joseph M
authors: JM
authors: Zabramski
mesh_terms: D020295:Brain Stem Neoplasms / Q000601:surgery*; D002102:Cadaver; D002426:Cavernous Sinus / Q000601:surgery; D003051:Cochlea / Q000033:anatomy & histology*; D035301:Cranial Fossa, Middle / Q000601:surgery*; D004210:Dissection; D034381:Hearing Loss / Q000517:prevention & control*; D006801:Humans; D019635:Neurosurgical Procedures / Q000379:methods*; D010579:Petrous Bone / Q000601:surgery*; D013701:Temporal Bone / Q000601:surgery
keywords: GSPN = greater superficial petrosal nerve; IAC = internal acoustic canal; ICA = internal carotid artery; V3 = maxillary branch of the trigeminal nerve; anterior petrosal approach; cochlea; hearing; skull base