title: Endoscopic endonasal approach for nonvestibular schwannomas.
abstract: BACKGROUND
  Nonvestibular schwannomas of the skull base often represent a challenge owing to their anatomic location. With improved techniques in endoscopic endonasal skull base surgery, resection of various ventral skull base tumors, including schwannomas, has become possible.
  
  
  OBJECTIVE
  To assess the outcomes of using endoscopic endonasal approach (EEA) for nonvestibular schwannomas of the skull base.
  
  
  METHODS
  Seventeen patients operated on for skull base schwannomas by EEA at the University of Pittsburgh Medical Center from 2003 to 2009 were reviewed.
  
  
  RESULTS
  Three patients underwent combined approaches with retromastoid craniectomy (n = 2) and orbitopterional craniotomy (n = 1). Three patients underwent multistage EEA. The rest received a single EEA operation. Data on degree of resection were found for 15 patients. Gross total resection (n = 9) and near-total (>90%) resection (n = 3) were achieved in 12 patients (80%). There were no tumor recurrences or postoperative cerebrospinal fluid leaks. In 3 of 7 patients with preoperative sensory deficits of trigeminal nerve distribution, there were partial improvements. Patients with preoperative reduced vision (n = 1) and cranial nerve VI or III palsies (n = 3) also showed improvement. Five patients had new postoperative trigeminal nerve deficits: 2 had sensory deficits only, 1 had motor deficit only, and 2 had both motor and sensory deficits. Three of these patients had partial improvement, but 3 developed corneal neurotrophic keratopathy.
  
  
  CONCLUSIONS
  An EEA provides adequate access for nonvestibular schwannomas invading the skull base, allowing a high degree of resection with a low rate of complications.
authors.affiliation: University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Samuel S
authors.initials: SS
authors.lastname: Shin
authors.forename: Paul A
authors.initials: PA
authors.lastname: Gardner
authors.forename: S Tonya
authors.initials: ST
authors.lastname: Stefko
authors.forename: Ricky
authors.initials: R
authors.lastname: Madhok
authors.forename: Juan C
authors.initials: JC
authors.lastname: Fernandez-Miranda
authors.forename: Carl H
authors.initials: CH
authors.lastname: Snyderman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003399:Craniotomy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000473:pathology / Q000601:surgery*; D009442:Neurilemmoma / Q000473:pathology / Q000601:surgery*; D044583:Neuroendoscopy / Q000295:instrumentation / Q000379:methods*; D012189:Retrospective Studies; D019291:Skull Base / Q000473:pathology / Q000601:surgery*; D019292:Skull Base Neoplasms / Q000473:pathology / Q000601:surgery*; D055815:Young Adult