gms | German Medical Science

63rd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Japanese Neurosurgical Society (JNS)

German Society of Neurosurgery (DGNC)

13 - 16 June 2012, Leipzig

Outcome analysis of the randomized multi-center study on idiophatic normal pressure hydrocephalus (SVASONA)

Meeting Abstract

  • J. Lemcke - Neurochirurgie, Unfallkrankenhaus Berlin, Germany
  • U. Meier - Neurochirurgie, Unfallkrankenhaus Berlin, Germany
  • C. Müller - Neurochirurgie, Ernst-Moritz-Arndt-Universität Greifswald, Germany
  • M. Fritsch - Neurochirurgie, Ernst-Moritz-Arndt-Universität Greifswald, Germany
  • U. Kehler - Neurochirurgie, Asklepios Klinik Altona, Hamburg, Germany
  • N. Langer - Neurochirurgie, Asklepios Klinik Altona, Hamburg, Germany
  • M. Kiefer - Neurochirurgie, Universitätskliniken des Saarlandes, Homburg/Saar, Germany
  • R. Eymann - Neurochirurgie, Universitätskliniken des Saarlandes, Homburg/Saar, Germany
  • M.U. Schuhmann - Neurochirurgie, Eberhard-Karls-Universität Tübingen, Germany
  • A. Speil - Neurochirurgie, Eberhard-Karls-Universität Tübingen, Germany
  • F. Weber - Neurochirurgie, Krankenhaus Köln-Merheim, Germany
  • V. Remenez - Neurochirurgie, Krankenhaus Köln-Merheim, Germany
  • V. Rohde - Neurochirurgie, Georg-August-Universität Göttingen, Germany
  • H.C. Ludwig - Neurochirurgie, Georg-August-Universität Göttingen, Germany
  • D. Stengel - Zentrum für Klinische Forschung, Unfallkrankenhaus Berlin und Ernst-Moritz-Arndt-Universität Greifswald, Germany

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS). Leipzig, 13.-16.06.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. DocSA.10.07

doi: 10.3205/12dgnc376, urn:nbn:de:0183-12dgnc3760

Published: June 4, 2012

© 2012 Lemcke et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: The Dutch hydrocephalus study in the 1990s proved the superiority of LPVs in the therapy of the idiopathic normal pressure hydrocephalus and simultaneously uncovered the enormous risk of overdrainage complications for the use of low pressure valves without a gravitational compensation. The aim of the SVASONA study was to prove that an excellent clinical outcome and a low rate of overdrainage complications can be achieved with gravitational valves. The aim of the outcome analysis is to underline the findings about the relation between LPVs and a favourable clinical outcome.

Methods: In seven German centers, who are experienced in the treatment of iNPH, patients were enrolled in the SVASONA study after passing clinical examination, radiological assessment and the CSF infusion test, CSF tap test and / or continuous ICP measurement. Those patients with a diagnosed iNPH were randomly assigned in a treatment group with a ventriculoperitoneal (vp) shunt with a programmable valve without a gravitational unit or a treatment group with a programmable valve with a gravitational unit. The patients were followed up 3, 6 and 12 months after surgery. The primary goal was to determine the incidence of overdrainage complications. The second study goal was the clinical outcome after 6 and 12 months.

Results: From 2006 to 2010, 150 patients were included in the study. Due to a significantly lower risk of overdrainage complications in the treatment group with gravitational units, the study was stopped according to the protocol after the planned interim analysis. 69% of the patients in the treatment group without a gravitational valve and 86% of the patients in the group with gravitational valves showed an excellent, improved or fair outcome according to the Black grading scale after 6 months. After 12 months 75% respectively 86% were registered. The difference was not significant. According to the Kiefer score, a significant clinical improvement was recorded in the group without gravitational valves (baseline 7.5; 6 months 4.8; 12 months 3.8) and in the group with gravitational valves (baseline 7.6; 6 months 3.8; 12 months 3.5).

Conclusions: Whereas a significant difference between the complication rates of the two treatment groups was evident, there is only a tendency in the difference between the outcomes measured by specific iNPH scores. These findings underline that gravitational valves prevents the risk of overdrainage but do not suppress the favourable outcomes achieved with LPVs.