title: Navigated minimally invasive presigmoidal suprabulbar infralabyrinthine approach to the jugular foramen without rerouting of the facial nerve.
abstract: BACKGROUND
  Jugular foramen tumors are rare and challenging lesions for skull base surgeons because of their difficult operative accessibility. Various surgical approaches to the jugular foramen have been described to overcome the morbidity of standard petrosectomy.
  
  
  OBJECTIVE
  To describe the surgical anatomy of a novel route to the jugular foramen without opening the fallopian canal, the navigated tailored presigmoidal suprabulbar infralabyrinthine approach.
  
  
  METHODS
  Ten cadaver heads were dissected under navigational guidance on both sides to examine the advantages and limitations of the presigmoidal suprabulbar infralabyrinthine approach without opening the fallopian canal. Mastoidectomy was performed by using a high-speed drill. Under navigation guidance, the sigmoid sinus, jugular bulb, posterior semicircular canal, and fallopian canal were located and preserved. The jugular foramen with the extradural part of the IXth, Xth, and XIth nerve were identified.
  
  
  RESULTS
  Measurements of the surgical corridor and exposed petrous bone area on high-resolution computed tomography showed that the navigated presigmoidal suprabulbar infralabyrinthine approach without opening the fallopian canal is a suitable route for extradural jugular foramen lesions with limited extension (approach height 5.59 ± 0.16 mm; approach width 7.68 ± 0.18 mm; approach surface 33.73 ± 1.37 mm; approach depth 32.92 ± 0.21 mm; vertical angle α of the surgical approach 41.3° ± 0.9°; horizontal angle β of the surgical approach 40.5° ± 0.6°).
  
  
  CONCLUSIONS
  The navigation-guided presigmoidal suprabulbar infralabyrinthine approach is a minimally invasive approach for selected lesions of the jugular foramen with preservation of the fallopian canal, labyrinthine block, and sigmoid sinus. This approach is suited for C1, De1, De2, Di1, and Di2 tumors according to the Fisch classification.
authors.affiliation: Department of Neurosurgery, Medical School Hannover, Hannover, Germany. Cinibulak.Zafer@mh-hannover.de
authors.forename: Zafer
authors.initials: Z
authors.lastname: Cinibulak
authors.forename: Joachim K
authors.initials: JK
authors.lastname: Krauss
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakamura
mesh_terms: D000368:Aged; D007758:Ear, Inner / Q000000981:diagnostic imaging / Q000601:surgery*; D005154:Facial Nerve / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D015192:Infratentorial Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D038361:Neuronavigation / Q000379:methods*; D011859:Radiography