title: The use of intraoperative navigation for percutaneous procedures at the skull base including a difficult-to-access foramen ovale.
abstract: BACKGROUND
  We describe the use of an intraoperative CT scan obtained using the Medtronic O-arm (Littleton, Massachusetts) for image-guided cannulation of the foramen ovale not previously accessible with the use of fluoroscopy alone. Unlike previously described procedures, this technique does not require placement of an invasive head clamp and may be used with an awake patient.
  
  
  OBJECTIVE
  To describe the use of intraoperative neuronavigation for accessing skull base foramina and, specifically, cannulating of the foramen ovale during percutaneous rhizotomy procedures using an intraoperative image guidance CT scanner (Medtronic O-arm, Littleton, Massachusetts).
  
  
  METHODS
  A noninvasive Landmark Fess Strap attached to a spine reference frame was applied to the heads of 4 patients who harbored a difficult-to-access foramen ovale. An intraoperative HD3D skull base scan using a Medtronic O-arm was obtained, and Synergy Spine software was used to create 3D reconstructions of the skull base. Using image guidance, we navigated the needle to percutaneously access the foramen ovale by the use of a single tract for successful completion of balloon compression of the trigeminal nerve.
  
  
  RESULTS
  All 4 patients (3 females and 1 male; ages 65-75) underwent the procedure with no complications.
  
  
  CONCLUSIONS
  Based on our experience, neuronavigation with the use of intraoperative O-arm CT imaging is useful during these cases.
authors.affiliation: Goodman Campbell Brain and Spine, Indiana University Department of Neurological Surgery, Indianapolis, Indiana 46202, USA.
authors.forename: Bradley N
authors.initials: BN
authors.lastname: Bohnstedt
authors.forename: R Shane
authors.initials: RS
authors.lastname: Tubbs
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Cohen-Gadol
mesh_terms: D000368:Aged; D005260:Female; D054085:Foramen Ovale / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D016343:Monitoring, Intraoperative / Q000379:methods; D038361:Neuronavigation / Q000009:adverse effects / Q000379:methods*; D019051:Rhizotomy / Q000009:adverse effects / Q000379:methods; D019291:Skull Base / Q000601:surgery*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014276:Trigeminal Nerve / Q000601:surgery