title: Adjustable vs set-pressure valves decrease the risk of proximal shunt obstruction in the treatment of pediatric hydrocephalus.
abstract: BACKGROUND
  The use of programmable shunt valves has increased dramatically in the practice of pediatric hydrocephalus. Despite theoretical advantages, it remains unclear if the use of programmable vs set-pressure valves affects shunt outcome.
  
  
  METHODS
  The clinical and radiological records of all pediatric patients undergoing ventriculoperitoneal (VP), ventriculopleural (VPl), and ventriculoatrial (VA) shunt surgery from 2001 to 2004 at an academic institution were reviewed. The association of programmable vs set-pressure valves with subsequent shunt revision was assessed by Kaplan-Meier shunt survival plots and log-rank analysis.
  
  
  RESULTS
  A total of 279 VP, VPl, and VA shunt surgeries were performed on patients with median (interquartile range) age of 4 (1-14) years (161 male, 118 female; 158 communicating, 122 obstructive hydrocephalus). Programmable valves were used in 76 (27%) cases and set-pressure valves in 203 (73%). At mean+/-SD follow-up of 17 +/- 13 months, programmable vs set-pressure valves were associated with reduced risk of both overall shunt revision [26 (35%) vs 109 (54%); relative risk (RR) (95% CI); 0.61 (0.41-0.91), p = 0.016] and proximal obstruction [9 (12%) vs 58 (28%); RR (95% CI); 0.39 (0.27-0.80), p = 0.006]. There was no difference in distal obstruction [3 (4%) vs 11 (5%) cases], infection [6 (8%) vs 12 (6%) cases], valve obstruction [0 (0%) vs 4 (2%)], or shunt disconnection [2 (3%) vs 1 (1%)] between adjustable and set-pressure valves, respectively.
  
  
  CONCLUSIONS
  In our experience, the use of programmable vales was associated with a decreased risk of proximal shunt obstruction and shunt revision. Programmable valves may be preferred in patients frequently experiencing proximal shunt failure. A prospective, controlled study is warranted to evaluate the potential value of adjustable vs set-pressure valve systems.
authors.affiliation: Division of Pediatric Neurosurgery, Department of Neurosurgery, Johns Hopkins School of Medicine, 600 North Wolfe Street, Meyer 8-161, Baltimore, MD 21287, USA. mmcgirt1@jhmi.edu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: McGirt
authors.forename: Donald W
authors.initials: DW
authors.lastname: Buck
authors.forename: Daniel
authors.initials: D
authors.lastname: Sciubba
authors.forename: Graeme F
authors.initials: GF
authors.lastname: Woodworth
authors.forename: Benjamin
authors.initials: B
authors.lastname: Carson
authors.forename: Jon
authors.initials: J
authors.lastname: Weingart
authors.forename: George
authors.initials: G
authors.lastname: Jallo
mesh_terms: D000293:Adolescent; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects* / Q000295:instrumentation; D002648:Child; D002675:Child, Preschool; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus / Q000150:complications / Q000601:surgery*; D007223:Infant; D019586:Intracranial Hypertension / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control*; D012189:Retrospective Studies; D018570:Risk Assessment; D012984:Software; D017211:Treatment Failure