title: Clinical validation of percutaneous cochlear implant surgery: initial report.
abstract: OBJECTIVE
  Percutaneous cochlear implant surgery consists of a single drill path from the lateral mastoid cortex to the cochlea via the facial recess. We sought to clinically validate this technique in patients undergoing traditional cochlear implant surgery.
  
  
  METHODS
  Prospective clinical trial.
  
  
  METHODS
  After institutional regulatory board-approved protocols, five ears were studied via the following steps. 1) In the clinic under local anesthesia, bone-implanted anchors were placed surrounding each mastoid. 2) Temporal-bone computed tomography (CT) scans were obtained. 3) On the CT scans, paths were planned from the lateral mastoid cortex, through the facial recess, to the basal turn of the cochlea both "manually" and "automatically" using computer software. 4) Customized microstereotactic frames were rapid-prototyped to serve as drill guides constraining the drill to follow the appropriate path. 5) During cochlear implant surgery, after drilling of the facial recess, drill guides were mounted on the bone-implanted anchors. 6) Accuracy of paths was assessed via intraoperative photodocumentation.
  
  
  RESULTS
  All surgical paths successfully traversed the facial recess and hit the basal turn of the cochlea. Distance in millimeters (average +/- SD) from the midpoint of the drill to the facial nerve was 1.18 +/- 0.68 for the "manual" path and 1.24 +/- 0.44 mm for the "automatic" path and for the chorda tympani 0.986 +/- 0.48 for the "manual" path and 1.22 +/- 0.62 for the "automatic" path.
  
  
  CONCLUSIONS
  Percutaneous cochlear implant access using customized drill guides based on preoperative CT scans and image-guided surgery technology can be safely accomplished.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University, Nashville, Tennessee 37232-8605, USA. robert.labadie@vanderbilt.edu
authors.forename: Robert Frederick
authors.initials: RF
authors.lastname: Labadie
authors.forename: Jack H
authors.initials: JH
authors.lastname: Noble
authors.forename: Benoit M
authors.initials: BM
authors.lastname: Dawant
authors.forename: Ramya
authors.initials: R
authors.lastname: Balachandran
authors.forename: Omid
authors.initials: O
authors.lastname: Majdani
authors.forename: J Michael
authors.initials: JM
authors.lastname: Fitzpatrick
mesh_terms: D019929:Cochlear Implantation / Q000295:instrumentation / Q000379:methods*; D003054:Cochlear Implants; D006801:Humans; D011446:Prospective Studies; D013701:Temporal Bone / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed