title: Distal slit valve and clinically relevant CSF overdrainage in children with hydrocephalus.
abstract: BACKGROUND
  Distal slit valve (DSV) is a system designed for the treatment of hydrocephalus. It has been assumed that, by dispensing with an anti-siphon (AS) mechanism, the DSV induces a set of clinical symptoms associated with fluid overdrainage in patients. Nonetheless, there is no published evidence to support this assumption.
  
  
  METHODS
  Thus, to determine whether such an association is valid, we reviewed the records of 101 hydrocephalic patients (150 procedures) who had DSVs placed at our institution. The records of 40 hydrocephalic patients (69 procedures) in whom anti-siphon devices (AS) were placed were also reviewed.
  
  
  RESULTS
  One DSV patient presented with slit ventricle syndrome (SVS) and low intracranial pressure (ICP). No DSV patients had postoperative subdural collection. One AS patient had a postoperative subdural collection. Thirty-one DSV patients (31%) each required one revision, and 8 (8%) required more than one revision. Twelve AS patients (30%) required one revision and 8 AS patients (20%) required more than one revision. No significant differences were found between the DSV and AS groups in number of revisions, infections or overdrainage.
  
  
  CONCLUSIONS
  We did not find a direct correlation between clinically relevant CSF overdrainage and DSV.
authors.affiliation: Division of Neurosurgery, Pediatric Neurosurgery, University of California at Los Angeles School of Medicine, Box 957039, Los Angeles, CA 90095-7039, USA.
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Virella
authors.forename: Marcelo
authors.initials: M
authors.lastname: Galarza
authors.forename: Michael
authors.initials: M
authors.lastname: Masterman-Smith
authors.forename: Rafael
authors.initials: R
authors.lastname: Lemus
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Lazareff
mesh_terms: D000293:Adolescent; D002552:Cerebral Ventricles / Q000473:pathology; D015170:Cerebrospinal Fluid Pressure; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D006261:Headache / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D006801:Humans; D006849:Hydrocephalus / Q000503:physiopathology / Q000628:therapy*; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D012086:Reoperation; D012189:Retrospective Studies; D017287:Ventriculoperitoneal Shunt / Q000009:adverse effects*