Download PDF
Eur J Pediatr Surg 1999; 9: 23-26
DOI: 10.1055/s-2008-1072307
Original article

© Georg Thieme Verlag KG Stuttgart · New York

New Valves - New Dangers? 22 Valves (38 Probes) Designed in the 'Nineties in Ultralong-Term Tests (365 Days)

J.  Oikonomou , A.  Aschoff , B.  Hashemi , S.  Kunze
  • Department of Neurosurgery, University of Heidelberg, Im Neuenheimer Feld 400, Heidelberg, Germany
Further Information

Publication History

Publication Date:
25 March 2008 (online)

  PDF Download  Permissions and Reprints

Abstract

In the nineties, more than 30 valves have been launched, most are "clones", but some introduce new concepts (Diamond, Siphon-Guard, PaediGAV). Of the 22 designs we tested, 20 have no previous tests and 3 are low-cost valves from Mexico (Dewimed), Zimbabwe (Harare-shunt) and England (Nottingham Shunt). 27 were tested using non-stop-perfusions for 365 days, 8 for 168-294 and 3 for 2 days.

Results: Ranking of the mean relative deviation: adjustable valves 19%, gravitational 34%, simple ball 51 %, diaphragm 73%, distal slit 74 % and autoregulating valves 121 %. Ranking of physiological flow properties: gravitational >EquiflowTM >autoregulating >adjustable >ball >diaphragm >distal slit. Safety: The Equiflow were highly susceptible to external pressure.

Conclusion: Most valves designed in the nineties showed inaccuracy, long-term-drifts, safety deficits and hydraulic mismanagement similar to more than 400 previously tested probes. With regard to accuracy and drift the ball designs were superior, but simple and adjustable ball valves are at risk of overdrainage. The gravitational ball valves (Cordis GCA, Miethke valves) showed the closest relation to physiological flow requirements.

Key words

Bench-test - Cerebrospinal fluid - Cerebrospinal fluid shunts - Gravitational valves - Hydrocephalus - CSF overdrainage

      >