title: Hydrocephalus associated with vestibular schwannomas: management options and factors predicting the outcome.
abstract: OBJECTIVE
  The current, generally accepted optimal management for hydrocephalus related to vestibular schwannomas (VSs) is primary tumor removal, with further treatment reserved only for patients who remain symptomatic. Previous studies have shown, however, that this management can lead to an increase in surgery-related complications. In this study, the authors evaluated their experience with the treatment of such patients, with the aim of identifying the following: 1) the parameters correlating to the need for specific hydrocephalus treatment following VS surgery; and 2) patients at risk for developing hydrocephalus-related complications.
  
  
  METHODS
  This was a retrospective study of a 400-patient series. The complication rates and outcomes following primary hydrocephalus treatment versus primary VS removal were compared. Patients undergoing primary tumor removal were further subdivided on the basis of the need for subsequent hydrocephalus treatment. The 3 categories of parameters tested for correlation with the need for such subsequent treatment as well as with heightened risk for developing complications were patient-, tumor-, and hydrocephalus-related.
  
  
  RESULTS
  Of the entire series, 53 patients presented with hydrocephalus. Forty-eight of 53 patients underwent primary VS surgery, of whom 42 (87.5%) did not require additional hydrocephalus treatment. Of the 6 patients who did require additional hydrocephalus treatment, only 3 ultimately required a VP shunt. Factors correlating to the need of hydrocephalus treatment after VS removal were large tumor size, irregular tumor surface, and severe preoperative hydrocephalus. Patients with a longer symptom duration prior to surgery, those with polycyclic tumors, or with inhomogeneous VS, were at heightened risk for the development of CSF leaks. The general and functional outcome of surgery showed no correlation to the presence of preoperative hydrocephalus.
  
  
  CONCLUSIONS
  Primary tumor removal is the optimum management of disease in patients with VS with associated hydrocephalus; it leads to resolution of the hydrocephalus in the majority of cases, and the outcome is similar to that of patients without hydrocephalus. Certain factors may aid in identifying patients at risk for developing persistent hydrocephalus as well as those at risk for CSF leaks.
authors.affiliation: International Neuroscience Institute, Hannover, Germany. vgerganov@gmail.com
authors.forename: Venelin M
authors.initials: VM
authors.lastname: Gerganov
authors.forename: Ariyan
authors.initials: A
authors.lastname: Pirayesh
authors.forename: Mohsen
authors.initials: M
authors.lastname: Nouri
authors.forename: Nirjhar
authors.initials: N
authors.lastname: Hore
authors.forename: Wolf O
authors.initials: WO
authors.lastname: Luedemann
authors.forename: Shizuo
authors.initials: S
authors.lastname: Oi
authors.forename: Amir
authors.initials: A
authors.lastname: Samii
authors.forename: Madjid
authors.initials: M
authors.lastname: Samii
mesh_terms: D000328:Adult; D065634:Cerebrospinal Fluid Leak; D002559:Cerebrospinal Fluid Rhinorrhea / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus / Q000503:physiopathology / Q000601:surgery*; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control*; D011300:Preoperative Care; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D017287:Ventriculoperitoneal Shunt; D014696:Ventriculostomy