title: Novel method for controlling cerebrospinal fluid flow and intracranial pressure by use of a tandem shunt valve system.
abstract: OBJECTIVE
  Programmable shunt valve systems have improved the management of patients with hydrocephalus. However, associated problems such as over-drainage and slit-like ventricles, even in patients with anti-siphon devices installed, still remain unresolved.
  
  
  METHODS
  We conceived a novel tandem shunt valve system to overcome the problems with existing shunt valve systems. Experiments were performed in vitro and a manometer was used to measure the results.
  
  
  RESULTS
  Manometric measurements in vitro with the tandem shunt valve system demonstrated that it effectively controlled the final pressure under varying flow rates. This novel system was applied to 2 intractable cases (over-drainage and slit-like ventricles) with good results.
  
  
  CONCLUSIONS
  The tandem shunt valve system has therapeutic potential not only for over-drainage and slit-like ventricles, but also for uncontrollable hydrocephalus, by precisely controlling the cerebral spinal fluid flow rate.
authors.affiliation: Department of Neurosurgery, Tokyo Women's Medical University, Tokyo, Japan. yaihara@nij.twmu.ac.jp
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Aihara
authors.forename: Takakazu
authors.initials: T
authors.lastname: Kawamata
authors.forename: Tetsuryu
authors.initials: T
authors.lastname: Mitsuyama
authors.forename: Tomokatsu
authors.initials: T
authors.lastname: Hori
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Okada
mesh_terms: D001932:Brain Neoplasms / Q000150:complications; D002557:Cerebrospinal Fluid Shunts / Q000295:instrumentation*; D002648:Child; D004582:Electronics, Medical; D004660:Encephalitis / Q000150:complications; D004867:Equipment Design; D005260:Female; D005910:Glioma / Q000150:complications; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology / Q000601:surgery*; D007223:Infant; D007427:Intracranial Pressure; D008297:Male; D008365:Manometry / Q000295:instrumentation*; D013290:Streptococcal Infections / Q000150:complications; D013292:Streptococcus agalactiae