O.104 Treatment of normal pressure hydrocephalus using the GAV shunt system: Preliminary results of a Spanish multicentre study

Abstract

Introduction: Surgical treatment of chronic hydrocephalus in an adult requires use of a shunt system that combines low-pressure opening with the absence of overdrainage phenomena. We present the preliminary results of a prospective multicentre study involving 13 hospitals in Spain of treatment of normal pressure hydrocephalus (NPH) with a gravity assisted shunt (GAV; Aesculap), the main purpose of which was to evaluate its efficacy and safety, as well as analyse possible factors influencing patient evolution. Material and Method Design: This prospective, multicentre study of clinical practice with a common protocol for treatment of adult idiopathic hydrocephalus included 136 patients (59% men; age: 73.4±6.4). Of these, six-month follow-up data are available for 62 patients and twelve months for 33. Data were recorded on epidemiological details, symptoms, evolution time, neuroradiological findings, vascular risk factors, and rout/ICP records. The main outcome variables were symptoms associated with hydrocephalus, measured with the NPH scale (gait, sphincter control and cognitive function). Secondary outcome variables included evolution according to radiological parameters and post-surgical complications. Statistics: ANOVA tests. Results: A significant improvement was noted in all the parameters of the NPH scale (gait: 3.2±1.0 vs 2.5±1.1 vs 2.2±1.1; cognitive function: 2.1±0.9 vs 1.8±0.9 vs 1.7±0.9; sphincter control: 2.9±1.2 vs 2.5±1.3 vs 2.4±1.3; p<0.05) highly evident in the third month and slightly less so in the sixth month, with a tendency to stabilise after 12 months. No association was found between improvement and demographic data, evolution time, vascular risk factors, rout value or radiological findings. The complications were less than 5%. Conclusion: The GAV shunt system proves highly efficient for the treatment of hydrocephalus, with a low rate of complications. Most patients showed improvement within six months.