Is there a correlation between operative results and change in ventricular volume after shunt placement? A study of 60 cases of idiopathic normal-pressure hydrocephalus.
In patients with communicating or normal-pressure hydrocephalus, ventricular volume decreases following implantation of differential pressure valves. We implanted hydrostatic (Miethke dual-switch) valves in 60 patients with normal-pressure hydrocephalus (NPH) between September 1997 and December 2001. The patients underwent CT 1 year after operation, and we measured the Evans index. Although 83% of the patients showed no change in ventricular volume as assessed by this index, 72% nevertheless showed good to excellent and 16% satisfactory clinical improvement, while 12% showed no improvement. Moderate or marked reduction in ventricular size was observed in 17%, of whom 40% of these patients showed good to excellent and 20% satisfactory clinical improvement; 40% showed unsatisfactory improvement. The favourable outcome following implantation of a hydrostatic shunt thus did not correlate with decreased ventricular volume 1 year after operation, better outcomes being observed in patients with little or no alteration in ventricular size than in those with a marked decrease. Postoperative change in ventricular volume in NPH thus does not have the same significance as in patients with high-pressure hydrocephalus.
Department of Neurosurgery, Unfallkrankenhaus Berlin, Warener Strasse 7, 12683 Berlin, Germany, ullrich.meier@ukb.de
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Meier
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Gräwe
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Stockheim
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D000368:Aged; D002552:Cerebral Ventricles / Q000503:physiopathology* / Q000601:surgery*; D014695:Cerebral Ventriculography; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D017060:Patient Satisfaction; D012720:Severity of Illness Index; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt