title: Long-term follow-up data from the Shunt Design Trial.
abstract: BACKGROUND
  A previously reported multicenter randomized trial assessed whether 2 new shunt valve designs would reduce shunt failure rates compared to differential pressure valves. The study did not show a significant difference in the time to first shunt failure. Patients entered the trial between October 1, 1993, and October 31, 1995. The primary results were based on the patients' status as of October 31, 1996 (a minimum follow-up of 1 year). This report describes the late complications based on the patients' most recent follow-up.
  
  
  METHODS
  Three hundred and forty-four hydrocephalic children at 12 North American and European centers were randomized to 1 of 3 valves: a standard differential pressure valve; a Delta valve (PS Medical-Medtronic) or a Sigma valve (NMT Cordis). Patients were followed until their first shunt failure. Shunt failure was defined as shunt surgery for obstruction, overdrainage, loculation or infection. If the shunt did not fail, follow-up was continued until August 31, 1999.
  
  
  RESULTS
  One hundred and seventy-seven patients had shunt failure. Shunt obstruction occurred in 131, overdrainage in 13, loculated ventricles in 2 and infection in 29. The overall shunt survival was 62% at 1 year, 52% at 2 years, 46% at 3 years, 41% at 4 years. The survival curves for the 3 valves were similar to those from the original trial and did not show a survival advantage for any particular valve.
  
  
  CONCLUSIONS
  Prolonged follow-up to date does not alter the primary conclusions of the trial: there does not appear to be one valve that is clearly the best for the initial treatment of pediatric hydrocephalus.
authors.affiliation: Division of Pediatric Neurosurgery, Primary Children's Medical Center, University of Utah, Salt Lake City, Utah, USA. john.kestle@hsc.utah.edu
authors.forename: J
authors.initials: J
authors.lastname: Kestle
authors.forename: J
authors.initials: J
authors.lastname: Drake
authors.forename: R
authors.initials: R
authors.lastname: Milner
authors.forename: C
authors.initials: C
authors.lastname: Sainte-Rose
authors.forename: G
authors.initials: G
authors.lastname: Cinalli
authors.forename: F
authors.initials: F
authors.lastname: Boop
authors.forename: J
authors.initials: J
authors.lastname: Piatt
authors.forename: S
authors.initials: S
authors.lastname: Haines
authors.forename: S
authors.initials: S
authors.lastname: Schiff
authors.forename: D
authors.initials: D
authors.lastname: Cochrane
authors.forename: P
authors.initials: P
authors.lastname: Steinbok
authors.forename: N
authors.initials: N
authors.lastname: MacNeil
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus / Q000401:mortality / Q000601:surgery*; D007223:Infant; D007231:Infant, Newborn; D015996:Survival Rate; D013997:Time Factors; D017287:Ventriculoperitoneal Shunt / Q000295:instrumentation* / Q000379:methods