gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Advantages and drawbacks of adjustability – Experiences after implantation of 54 proGAVs for shunting of hydrocephalus

Vor- und Nachteile der Verstellbarkeit von Hydrozephalusventilen – Erfahrungen nach 54 Implantationen des proGAV zur Shunttherapie

Meeting Abstract

Search Medline for

  • corresponding author C. Sprung - Neurochirurgische Klinik, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin
  • H. Glocker - Neurochirurgische Klinik, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin
  • H.G. Schlosser - Neurochirurgische Klinik, Campus Virchow-Klinikum, Charité - Universitätsmedizin Berlin

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocFR.04.04

The electronic version of this article is the complete one and can be found online at:

Published: May 8, 2006

© 2006 Sprung 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 new proGAV represents the combination of a new adjustable differential-pressure unit with a “brake” in series with a gravitational device. Based on its construction principle, the proGAV should be capable of avoiding the main disadvantages of other so-called „programmable“ valves,which are as follows: The the necessity for repeated X-ray-controls, the sensitivity to irregular adjustments in MR and the ongoing danger of overdraining due to adjustable differential-pressure-valves.

Methods: From February 2004 to September 2005, we conducted a series of 54 patients (with one exception adults) suffering from hydrocephalus of different etiologies by implanting a proGAV-shunt. As a first step we were interested in the reliability of the new tools in determining the opening pressures thereby avoiding X-rays, in the ability to adjust the valve externally safely and in the ability to avoid irregular maladjustments. We then focused on the complications and the clinical results including the possibilities for improvement by readjustments.

Results: The outcome with 12 excellent and 15 good results among the 34 patients without the necessity of readjustments. This provides evidence for the reliability of the proGAV in avoiding most of the disadvantages of other adjustable devices. In 16 cases we saw an indication for lowering the opening pressure because we suspected functional underdrainage; 12 patients improved clinically more than radiologically. Out of 4 patients with overdrainage, 1 case of slit-ventricles revealed significant improvement and 3 hygromas resolved after increasing the opening pressure. The outcome of our series proves the ability of the new construction to avoid surgical replacement of the valve in at least 10 cases., On the other hand, one should refrain from the tendency to use adjustability just because the possibility is there. No spontaneous readjustments have been seen up to now.

Conclusions: The new theoretical concept and the first clinical and radiological results indicate that the proGAV is superior to other adjustable devices, at least in adults. The series is still small and the follow-up relatively short, thus a comparison with series using other adjustable valves remains preliminary up to now.