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58. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

26. bis 29.04.2007, Leipzig

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Rational classification of 268 hydrocephalus valves

Rationale Klassifikation von 268 Hydrozephalus-Ventilen

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  • corresponding author A. Aschoff - Neurochirurgische Universitätsklinik Heidelberg
  • M. Schlieter - Radiologische Universitätsklinik Heidelberg
  • M. Halatsch - Neurochirurgische Universitätsklinik Heidelberg
  • M. Hlavac - Neurochirurgische Universitätsklinik Heidelberg

Deutsche Gesellschaft für Neurochirurgie. 58. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC). Leipzig, 26.-29.04.2007. Düsseldorf: German Medical Science GMS Publishing House; 2007. DocP 100

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2007/07dgnc355.shtml

Published: April 11, 2007

© 2007 Aschoff et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.

Outline

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Objective: 268 valves were designed. The nomenclature is a chaos of 1. inventor/company or 2. fantasy terms (Diamond), which contain no real information. Others contain minimal informations on 3. valve body (burr hole), 4. shunt assembly (Unishunt), 5. age (neonatal), 6. special implantations (Hakim-Lumbar), 7. pressure ranges (Sophy SU3/8), 8. curves (Sigma) or 9. details (slit). 10. Some use advertising terms: “Programmable” suggests computer techology, the reality are simple adjustable springs. 11. Some terms are physically incorrect: The “flow-controlled” Orbis-Sigma is controlled by pressure. 12. The hydraulic properties are not standardized: MEDIUM often overlaps LOW/HIGH.

Type 1-9 contain no/minimal information and allow no useful classification, but avoid errors. In contrast the widely accepted term “programmable” leads to nonsense and “flow-controlled” to hydraulic confusions.

Methods: We analyzed the hydraulics and designs of 268 valves and developed a nomenclature based mainly on hydraulics in the vertical/horizontal position and on secondary criteria.

Results: The hydraulics require data on 1. the pressure curves (L-M-H or detailled curves) and 2. the variability. Conventional valves show prefixed curve (2.1), more recent are manually adjustable (2.2), have a pressure-dependent negative feedback-regulation (Orbis, Diamond, 2.3) or are controlled by gravity or. body position. The acting weight is the water column in the catheter distal to a collapse-switch (ASD 2.4) or implemented balls (gravitational valves, 2.5). All combinations (Strata, SiphonGuard, ProGAV) can be classified.

Subcriteria concern details (ball, slit, adjustment, “brakes”), materials, body design and shunt assembly.

Conclusions: Two hydraulic and four supplementary specifications allow a nearly complete and precise classification of all shunts including developments in the near future.