title: Prevalence and Surgical Implications of Dural Enhancement at the Porus Acusticus in Vestibular Schwannomas.
abstract: Demonstrate the association of radiographic dural enhancement with increased tumor adherence at the porus acusticus, which may influence completeness of resection and facial nerve outcome.
  
  
  
  Case series with chart review.
  
  
  
  Academic referral center.
  
  
  
  A total of 205 consecutive patients with histopathologically confirmed vestibular schwannoma (VS) were evaluated. Patients with tumors exhibiting dural enhancement on postgadolinium T1-weighted magnetic resonance imaging were identified and compared with matched controls. Completeness of resection, intraoperative details, and facial nerve outcomes were analyzed.
  
  
  
  Excluding strictly intracanalicular tumors (n = 32, 16%) and those with NF2 (n = 10, 4.9%), the presence of dural enhancement was radiographically confirmed in 16 (9.8%) cases. Paired analysis did not reveal significant baseline differences between cases and controls. Subtotal resection was performed in 5 (31%) of the 16 patients with tumors exhibiting dural enhancement, in contrast to 1 (3%) of the matched controls (P = .01). Four (25%) demonstrated increased tumor adherence at the porus acusticus intraoperatively, compared with 1 control (3%, P = .04). Long-term facial nerve function was similar between cases and controls (81% vs 84% House-Brackmann I-II function, P = 1.00).
  
  
  
  Dural enhancement is present in approximately 10% of extracanalicular VS. Dural enhancement at the porus acusticus may represent hypervascularity, dural reaction, or infiltration, and portends increased tumor adherence and greater likelihood of subtotal resection to preserve facial nerve function. To our knowledge, this is the first series that reports the prevalence of this phenomenon in VS and the potential surgical implications. Recognition preoperatively may be valuable toward patient counseling.
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Neil S
authors.initials: NS
authors.lastname: Patel
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Van Abel
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Colin L W
authors.initials: CL
authors.lastname: Driscoll
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Jamie J
authors.initials: JJ
authors.lastname: Van Gompel
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Neff
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: John I
authors.initials: JI
authors.lastname: Lane
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota, USA carlson.matthew@mayo.edu.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Carlson
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005154:Facial Nerve / Q000601:surgery; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009464:Neuroma, Acoustic / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000379:methods; D015995:Prevalence; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: acoustic neuroma; cranial base; meningioma; neurotology; skull base; vestibular schwannoma