gms | German Medical Science

65th Annual Meeting of the German Society of Neurosurgery (DGNC)

German Society of Neurosurgery (DGNC)

11 - 14 May 2014, Dresden

In vitro characterization of six types of flow- and gravity-dependent anti-siphon devices

Meeting Abstract

  • Florian Baptist Freimann - Klinik für Neurochirurgie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen; Klinik für Neurochirurgie, Charité – Universitätsmedizin Berlin
  • Takaoki Kimura - Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
  • Veit Rohde - Klinik für Neurochirurgie, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen
  • Ullrich-Wilhelm Thomale - Arbeitsbereich Pädiatrische Neurochirurgie, Charité – Universitätsmedizin Berlin

Deutsche Gesellschaft für Neurochirurgie. 65. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Dresden, 11.-14.05.2014. Düsseldorf: German Medical Science GMS Publishing House; 2014. DocMI.12.02

doi: 10.3205/14dgnc334, urn:nbn:de:0183-14dgnc3342

Published: May 13, 2014

© 2014 Freimann 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 beneficial effect of the augmentation of adjustable differential pressure valves with anti-siphon devices (ASD) for the treatment of overdrainage-related complications associated with ventriculoperitoneal shunting was recently demonstrated. The available studies focus mainly on gravitiy-assisted valves in the clinical application. Our aim was to provide comparable data on the pressure and flow characteristics of six different types of ASD (both flow- and gravity-dependent) in order to improve the understanding of those devices for their clinical application in the future.

Method: We analyzed three gravity-dependent ASD (Shuntassistant, Miethke; Gravity Compensating Accessory, Integra; SiphonX, Sophysa) and three flow-dependent ASD (Siphonguard, Codman; Delta Chamber, Medtronic; Anti-Siphon Device, Integra) regarding their flow and pressure characteristics. Defined conditions of differential pressure within a simulated shunt system were generated (ICP 0 to 40cmH2O, siphoning 0 to -40cmH2O). Flow and pressure conditions within the shunt system were measured for each device. In addition, the gravity-dependent ASDs were measured in seven defined spatial positions (0-90°).

Results: The flow characteristics of the three gravity-assisted ASD depended basically on the differential pressure and their spatial position. All three devices were able to reduce the siphoning effect but to different extents (flow at ICP: 10cmH2O, siphoning 20cmH2O at 0°/90°: SA: 7.1±1.2*/2.3±0.5*ml/min; GCA: 10.5±0.8/3.4±0.4*ml/min; SX 9.5±1.2*/4.7±1.9*ml/min compared to control: 11.1±0.4ml/min [*p<0.05]). In contrast, the flow characteristics of the flow-regulated ASD depended on the constellation of ICP and varying siphoning effects (flow at 10cmH2O, siphoning 0cmH2O/ siphoning 20cmH2O: DC 2.6±0.1/ 4±0.3*ml/min; ASD 2.5±0.2/ 0.8±0.4*ml/min; SG 0.8±0.2*/ 0.2±0.1*ml/h compared 2.8±0.2/ 11.1±0.4ml/min [*p<0.05]), which varied significantly among the devices.

Conclusions: The characterized ASD controlled the siphoning effect within a simulated shunt system to different degrees. The augmentation of adjustable differential pressure valves with ASD still seems to be appropriate, but comparative trials are needed in the future to answer which type of devices are superior for the clinical application.