title: Impingement of the carotid canal on the basal turn of the cochlea as pertaining to cochlear implantation.
abstract: OBJECTIVE
  To evaluate the relation of the basal turn of the cochlea with the carotid canal as pertaining to cochlear implantation.
  
  
  BACKGROUND
  Cochlear implantation is an established mode of treatment for patients with bilateral profound sensorineural hearing loss. An intricate knowledge of both the typical and atypical topography of the cochlea with the carotid canal is essential for safely conducting cochlear implantation.
  
  
  METHODS
  Fifty-eight cadaveric temporal bones were microdissected to expose the medial wall of the middle ear. To open the basal turn of the cochlea, the promontory was drilled. The carotid canal was unroofed to reveal the internal carotid artery. The minimum distance between the basal turn of the cochlea and the vertical part of the carotid canal was measured.
  
  
  RESULTS
  The minimum distance between the basal turn of the cochlea and the carotid canal ranged from 0 to 3.9 mm (mean ± SD, 1.3 ± 0.8 mm). The carotid canal was abutting the basal turn of the cochlea in three cases, and impingement of the carotid canal on the anterior cochlear wall was found in five (8.6%) cases.
  
  
  CONCLUSIONS
  Preoperative knowledge of findings like impingement (8.6%) and abutment (5.2%) of the carotid canal on the basal turn of the cochlea is of immense importance in cochlear implantation, which may otherwise lead to disastrous consequences during surgery.
authors.affiliation: *Departments of Anatomy and †Otolaryngology and Head Neck Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Anjali
authors.initials: A
authors.lastname: Singla
authors.forename: Tulika
authors.initials: T
authors.lastname: Gupta
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Gupta
authors.forename: Anjali
authors.initials: A
authors.lastname: Aggarwal
authors.forename: Daisy
authors.initials: D
authors.lastname: Sahni
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000601:surgery*; D019929:Cochlear Implantation; D007758:Ear, Inner / Q000601:surgery; D005260:Female; D006312:Hearing Loss, Bilateral / Q000601:surgery*; D006319:Hearing Loss, Sensorineural / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D013701:Temporal Bone / Q000601:surgery*; D055815:Young Adult