title: Study of Changing Intracranial Venous Drainage Patterns in Petroclival Meningioma.
abstract: OBJECTIVE
  To elucidate venous drainage patterns to avoid damage to the venous drainage route in the middle cranial fossa and superior petrosal sinus when employing the transpetrosal approach.
  
  
  METHODS
  Venous drainage patterns were assessed using three-dimensional computed tomography venography in 22 hemispheres of petroclival meningioma (PCM) cases from patients who underwent primary surgery and 40 hemispheres of control cases. Intracranial venous drainage patterns were compared between control cases and PCM cases.
  
  
  RESULTS
  The proportion of hemispheres with complete and medial superior petrosal sinus drainage patterns was lower in PCM cases. With regard to the superficial middle cerebral vein drainage pattern, the proportion of hemispheres with the cavernous sinus capture type was lower and the proportion with the emissary type was higher in PCM cases. The proportion of hemispheres with multiple greater anastomoses of the superficial middle cerebral vein was higher in PCM cases without the emissary-type and cavernous sinus capture-type patterns. When the venous drainage route of the cavernous sinus capture type and/or emissary type was disturbed, in particular, greater anastomosis via the vein of Labbè and the vein of Trolard was needed to control venous drainage flow.
  
  
  CONCLUSIONS
  In cases of venous drainage impairment secondary to PCM progression, the drainage route changed to the pterygoid plexus route through the emissary foramen and/or superior sagittal sinus and to the transverse sinus route through the greater anastomosis of the superficial middle cerebral vein. In the anterior transpetrosal approach, peeling off the dura propria of the trigeminal nerve of the foramen rotundum for petrous apex exposure may be associated with the potential risk of pterygoid plexus drainage route impairment.
authors.affiliation: Department of Neurosurgery, School of Medicine, Fujita Health University, Toyoake City, Aichi, Japan. Electronic address: kazu-adachi@rio.odn.ne.jp.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Adachi
authors.affiliation: Department of Neurosurgery, School of Medicine, Fujita Health University, Toyoake City, Aichi, Japan.
authors.forename: Motoharu
authors.initials: M
authors.lastname: Hayakawa
authors.affiliation: Department of Neurosurgery, School of Medicine, Fujita Health University, Toyoake City, Aichi, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Ishihara
authors.affiliation: Department of Neurosurgery, School of Medicine, Fujita Health University, Toyoake City, Aichi, Japan.
authors.forename: Tukasa
authors.initials: T
authors.lastname: Ganaha
authors.affiliation: Department of Neurosurgery, School of Medicine, Fujita Health University, Toyoake City, Aichi, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Nagahisa
authors.affiliation: Department of Neurosurgery, School of Medicine, Fujita Health University, Toyoake City, Aichi, Japan.
authors.forename: Mituhiro
authors.initials: M
authors.lastname: Hasegawa
authors.affiliation: Department of Neurosurgery, School of Medicine, Fujita Health University, Toyoake City, Aichi, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hirose
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002550:Cerebral Veins / Q000601:surgery*; D002560:Cerebrovascular Circulation; D000072226:Computed Tomography Angiography; D003392:Cranial Sinuses / Q000000981:diagnostic imaging / Q000601:surgery*; D004322:Drainage / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008579:Meningioma / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D010579:Petrous Bone / Q000601:surgery; D014656:Vascular Surgical Procedures / Q000379:methods*; D055815:Young Adult
keywords: Intracranial venous drainage; Petroclival meningioma; Transpetrosal approach