title: Tentorial detachment technique in the combined petrosal approach for petroclival meningiomas.
abstract: OBJECTIVE
  The combined petrosal approach is a suitable technique for the resection of medium-to-large petroclival meningiomas (PCMs). Multiple technical modifications have been reported to increase the surgical corridor, including the method of dural and tentorial opening. The authors describe their method of dural opening and tentorial resection, and detail the microanatomy related to their technique to clarify pitfalls and effects.
  
  
  METHODS
  The relationship of temporal bridging veins and cranial nerves (CNs) around the tentorial resection area was examined during the combined petrosal approach in 20 cadaveric specimens. The authors also reviewed their 23 consecutive clinical cases treated using this technique between 2002 and 2010, focusing on the effects and risks of the procedure.
  
  
  RESULTS
  In the authors' method, the tentorial resection extends from 5 to 10 mm anterior to the junction of the sigmoid sinus and the superior petrosal sinus ("sinodural point") to the trigeminal fibrous ring and the dural sleeve of CN IV. Temporal bridging veins enter the transverse sinus no more than 5 mm anterior to the sinodural point. The CN IV should be freed from its tentorial dural sleeve while avoiding disruption of the posterior cavernous sinus. The clinical data demonstrate a total resection rate of 78.3%, intraoperative estimated blood loss < 400 ml at a rate of 80.9%, and a venous congestion rate of 0%.
  
  
  CONCLUSIONS
  Understanding the anatomical relationship between the tentorium and temporal bridging veins and CNs IV-VI allows neurosurgeons the ability to develop a combined petrosal approach to PCMs that will effectively supply a wide operative corridor after resecting the tentorium, while significantly devascularizing tumors.
authors.affiliation: Division of Neurosurgery, Duke University Medical Center, Durham, North Carolina, USA. marikrt33@jg7.so-net.ne.jp
authors.forename: Mari
authors.initials: M
authors.lastname: Kusumi
authors.forename: Takanori
authors.initials: T
authors.lastname: Fukushima
authors.forename: Ankit I
authors.initials: AI
authors.lastname: Mehta
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Aliabadi
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nonaka
authors.forename: Allan H
authors.initials: AH
authors.lastname: Friedman
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fujii
mesh_terms: D000328:Adult; D000368:Aged; D002102:Cadaver; D002550:Cerebral Veins / Q000473:pathology; D003391:Cranial Nerves / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000503:physiopathology / Q000601:surgery*; D008579:Meningioma / Q000503:physiopathology / Q000601:surgery*; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods*; D010579:Petrous Bone / Q000601:surgery*; D019291:Skull Base / Q000601:surgery