title: Endoscopic transsphenoidal surgery using pedicle vascularized nasoseptal flap for cholesterol granuloma in petrous apex: A technical note.
abstract: BACKGROUND
  Compared with surgical resection, endoscopic transsphenoidal surgery (TSS) for cholesterol granuloma (CG) in the petrous apex (PA) is associated with local recurrence due to obstruction of the drainage route. We present a detailed procedure of an endoscopic TSS using pedicle vascularized nasoseptal flap (PVNF).
  
  
  METHODS
  A 40-year-old woman with a history of repeated surgery for left tympanitis was referred to our institution. Neurological examination revealed severe hearing loss in the left ear. Radiologic examination presented a round mass in the left PA and significant fluid collection in the mastoid air cells of the left temporal bone. CG was strongly suspected, and endoscopic TSS using PVNF was performed. Prior to endoscopic drainage, a PVNF was harvested from the mucosa of the ipsilateral nasal septum, with an attempt to preserve the sphenopalatine artery in the flap. Following this, puncture and adequate irrigation of the lesion was performed by endoscopic TSS, with neuro-navigation system assistance; the apex of PVNF was then placed into the lesion to prevent the obstruction of the drainage route. An absorbable polyglycolic acid sheet and fibrin glue were applied on the flap to prevent spontaneous deviation from the lesion.
  
  
  RESULTS
  The patient was discharged without any further neurological complications. Eight-month postoperative computed tomography images showed no recurrence; the drainage route was patent and the fluid collection in the left mastoid air cells was resolved. Moreover, hearing loss was improved.
  
  
  CONCLUSIONS
  Endoscopic TSS using PVNF may be one of available surgical options for PACG.
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Japan. Electronic address: nekozamurai@me.com.
authors: Yukitomo
authors: Y
authors: Ishi
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Japan. Electronic address: hiro-ko@med.hokudai.ac.jp.
authors: Hiroyuki
authors: H
authors: Kobayashi
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Japan. Electronic address: moccihiro@yahoo.co.jp.
authors: Hiroaki
authors: H
authors: Motegi
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Japan. Electronic address: du_en03_05@yahoo.co.jp.
authors: Shogo
authors: S
authors: Endo
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Japan. Electronic address: syamama1945@gmail.com.
authors: Shigeru
authors: S
authors: Yamaguchi
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Japan. Electronic address: terasas@med.hokudai.ac.jp.
authors: Shunsuke
authors: S
authors: Terasaka
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Japan. Electronic address: houkin@med.hokudai.ac.jp.
authors: Kiyohiro
authors: K
authors: Houkin
mesh_terms: D000328:Adult; D002784:Cholesterol; D004724:Endoscopy / Q000379:methods*; D005260:Female; D015745:Granuloma, Foreign-Body / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009300:Nasal Septum / Q000637:transplantation*; D010579:Petrous Bone / Q000000981:diagnostic imaging / Q000601:surgery*; D013524:Surgical Flaps; D014057:Tomography, X-Ray Computed
chemical_list: D002784:Cholesterol
keywords: Cholesterol granuloma; Endoscope; Nasoseptal flap; Petrous apex; Transsphenoidal surgery