title: Nonprogrammable and programmable cerebrospinal fluid shunt valves: a 5-year study.
abstract: OBJECTIVE
  Programmable valves (PVs) for shunting CSF have increasingly replaced nonprogrammable valves (NPVs). There have been only a few longer-term studies (≥ 5 years) conducted that have compared the effectiveness of NPVs with that of PVs for children with hydrocephalus, and only 1 study has reported NPVs as being favorable over PVs. The objective of this retrospective study was to compare the long-term survival of these 2 types of shunt valves.
  
  
  METHODS
  The authors collected data for all patients who underwent CSF shunt insertion or revision between January 1, 2000, and December 31, 2008. Patients underwent follow-up for a minimum of 2 years postoperatively. Statistical analyses were done using chi-square, Kaplan-Meier survival curve, and multivariate analyses.
  
  
  RESULTS
  A total of 616 valves were implanted, of which 313 were PVs and 303 were NPVs. Of these, 253 were original shunt implantations and 363 were revisions. The proportion of 5-year survival for NPVs (45.8%) was significantly higher than that for PVs (19.8%) (p = 0.0005, log-rank). The NPVs that survived longer than 6 months also survived through the 5th year better than the PVs (p = 0.0001).
  
  
  CONCLUSIONS
  The authors' data suggest that NPVs survive longer than PVs in children, but there is a need for prospective, case-control studies to confirm these data.
authors.affiliation: Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Hatlen
authors.forename: David B
authors.initials: DB
authors.lastname: Shurtleff
authors.forename: John D
authors.initials: JD
authors.lastname: Loeser
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Ojemann
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Avellino
authors.forename: Richard G
authors.initials: RG
authors.lastname: Ellenbogen
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016022:Case-Control Studies; D002557:Cerebrospinal Fluid Shunts; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus / Q000601:surgery*; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D019919:Prosthesis Implantation; D012086:Reoperation; D012189:Retrospective Studies; D013534:Survival