title: Experience with a gravitational valve in the management of symptomatic overdrainage in children with shunts.
abstract: OBJECTIVE
  Symptomatic overdrainage in children with shunt-treated hydrocephalus represents one of the more difficult shunt-related diseases and may require repeated surgery. Gravity-assisted valve design has become a standard device to avoid overdrainage in many European pediatric hydrocephalus centers. However, the use of a gravitational valve for relieving symptoms associated with overdrainage has not yet been addressed. The goal of this study was to evaluate the effectiveness of a gravitational valve in the treatment of symptomatic overdrainage in children with shunts.
  
  
  METHODS
  Seventeen children with an adjustable shunt system and symptomatic overdrainage were treated by insertion of a gravitational valve. Clinical and radiological outcome were monitored for a minimum of 12 months after surgery.
  
  
  RESULTS
  Implantation of a gravitational valve resulted in either resolution (n = 12) or improvement (n = 5) of the symptoms. In 1 patient, symptoms remained almost unchanged and the gravitational valve had to be upgraded, resulting in resolution of the symptoms. During follow-up, the pressure setting of the adjustable differential pressure valve had to be changed in 7 patients.
  
  
  CONCLUSIONS
  The gravitational valve was effective in improving symptomatic overdrainage in the majority of patients in the present study. Because the ideal pressure setting for a given patient is hard to determine a priori, adjustable valve systems appear to be beneficial.
authors.affiliation: Department of Neurosurgery, Technical University Munich, Klinikum rechts der Isar, Munich, Germany. mrweinzierl@googlemail.com
authors.forename: Martin R
authors.initials: MR
authors.lastname: Weinzierl
authors.forename: Franz-Josef
authors.initials: FJ
authors.lastname: Hans
authors.forename: Michael
authors.initials: M
authors.lastname: Stoffel
authors.forename: Markus F
authors.initials: MF
authors.lastname: Oertel
authors.forename: Marcus C
authors.initials: MC
authors.lastname: Korinth
mesh_terms: D000293:Adolescent; D002552:Cerebral Ventricles / Q000473:pathology; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006112:Gravitation; D020773:Headache Disorders / Q000209:etiology; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery*; D007223:Infant; D008297:Male; D011312:Pressure; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome