title: Gravity valves for idiopathic normal-pressure hydrocephalus: a prospective study with 60 patients.
abstract: OBJECTIVE
  Are hydrostatic valves superior to conventional differential pressure shunts in patients with normal-pressure hydrocephalus, with regard to the postoperative results of treatment and possible complications?
  
  
  METHODS
  From September 1997 to January 2002, 60 patients with idiopathic normal-pressure hydrocephalus were treated by surgical implantation of hydrostatic valve at the Unfallkrankenhaus Berlin. In a prospective study, the clinical examination and a CT examination were carried out preoperatively, postoperatively and 1 year after the operation.
  
  
  RESULTS
  One year after the operation, the clinical picture was very good for 33% of the patients, good for 33% and satisfactory or poor for 17%, each, of the patients. 3 dislocations (5%) of ventricular or abdominal catheters and three valve infections were found as valve-independent. As valve-dependent complications, underdrainage was found in 4 patients (7%) and radiological signs of overdrainage in 2 patients (3%), while 1 patient (1.7%) showed symptomatic over-drainage.
  
  
  CONCLUSIONS
  According to our experience, hydrostatic Dual-switch valves Aesulap are superior to conventional differential pressure shunts without an additional gravity unit especially with regard to the treatment of patients with idiopathic normal-pressure hydrocephalus, concerning both the postoperative results and the incidence of possible complications. A clinical improvement can be achieved for 83% of such patients.
authors.affiliation: Department of Neurosurgery, Unfallkrankenhaus Berlin, Germany. ullrich.meier@ukb.de
authors.forename: U
authors.initials: U
authors.lastname: Meier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002557:Cerebrospinal Fluid Shunts / Q000295:instrumentation* / Q000379:methods*; D019299:Decompression, Surgical / Q000295:instrumentation* / Q000379:methods; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000175:diagnosis / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D016896:Treatment Outcome