title: Ten years of clinical experience in the use of fixed-pressure versus programmable valves: a retrospective study of 159 patients.
abstract: OBJECTIVE
  The aim of this study was to present our 10-year experience with the use of fixed-pressure and programmable valves in the treatment of adult patients requiring cerebrospinal fluid (CSF) diversion.
  
  
  METHODS
  Patients (n = 159; 89 male and 70 female) suffering from hydrocephalus of various causes underwent CSF shunt implantation. Forty fixed-pressure and 119 programmable valves were initially implanted.
  
  
  RESULTS
  The observed revision rate was 40% in patients with fixed-pressure valves. In 20% of these patients, a revision due to valve mechanism malfunction was undertaken, and the initial valve was replaced with a programmable one. The revision rate in the adjustable-pressure valve subgroup was 20%. The infection rate for the fixed-pressure and programmable valve subgroups were 3%, and 1.7%, respectively. Similarly, subdural fluid collections were noticed in 17% and 4% of patients with fixed-pressure valves and programmable valves, respectively.
  
  
  CONCLUSIONS
  The revision and over-drainage rates were significantly lower when using programmable valves, and thus, this type of valve is preferred whenever CSF has to be diverted.
authors: Department of Neurosurgery, University Hospital of Larissa, Larissa, Greece.
authors: Maria
authors: M
authors: Mpakopoulou
authors: Alexandros G
authors: AG
authors: Brotis
authors: Haralampos
authors: H
authors: Gatos
authors: Konstantinos
authors: K
authors: Paterakis
authors: Kostas N
authors: KN
authors: Fountas
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D019736:Prostheses and Implants; D012189:Retrospective Studies; D012984:Software; D017287:Ventriculoperitoneal Shunt / Q000009:adverse effects* / Q000295:instrumentation*; D055815:Young Adult