In-vitro-testing of 1318 hydrocephalus valves. An overview of solved and unsolved problems
Between 1962 and 1979 only 121 valves have been tested. In 1980 Ekstedt published the first major series of 180 specimens. Now we register >1318 valves tested in vitro by 78 authors. Unfortunately cumulative or meta-analyses of the results are not available.
Materials and Methods
All papers including technical reports etc. related to valve-tests were evaluated; double publications of the same material were counted once, and papers of companies were excluded.
96% were investigated in 4 countries: 9.0% in USA and England, 14.6% in Sweden and 63.9% in Germany. The number of specimen per group ranged from 1–643, the tested designs from 1–87. Unfortunately in most early, and also current papers the pretest procedures (de-aeration, pre-perfundation) were not described. In 10 papers, the temperatures in 7 of the test-fluids are missing, the same is true for many methodological details. Most authors measured the resistance-pressure with a given flow, a few the flow dependent of p
- In-vitro-testing of 1318 hydrocephalus valves. An overview of solved and unsolved problems
- Open Access
- Available under Open Access This content is freely available online to anyone, anywhere at any time.
Cerebrospinal Fluid Research
- Online Date
- December 2004
- Online ISSN
- BioMed Central
- Additional Links