Risks in using siphon-reducing devices in adult patients with normal-pressure hydrocephalus: bench test investigations with Delta valves

Journal of Neurosurgery
M HassanJ Yamashita

Abstract

To elucidate the reason for malfunction of Delta valves in patients with normal-pressure hydrocephalus, the authors applied a new concept of the bench test and simulated intracranial pressure (ICP) to measure the resultant flow with a complete shunt system. Subcutaneous pressure on the valve, valve implantation site, and postural hydrostatic differential-pressure changes were simulated in this bench test designed for adult patients with normal-pressure hydrocephalus. Subcutaneous pressure ranged within 6.4 +/- 0.09 cm H2O (mean +/- standard deviation) on the 7th day after the implantation of the valve in rats. A linear correlation between valve closing pressures and the external pressure was observed: gradual increase of the latter resulted in an approximately equal rise in the closing pressure. Closing pressure ranged within the physiological variation of ICP (10 +/- 5 cm H2O) in the supine position. In the erect position it was higher than the physiological variation (+5 to -5 cm H2O) when the valve was placed at the level of the foramen of Monro and lower when placed at the level of the clavicle. This observation indicates that the subcutaneous pressure around the Delta valve significantly affects its closing pressure. An ex...Continue Reading

References

Jan 1, 1991·Pediatric Neurosurgery·C Sainte-RoseE B Hendrick
Mar 1, 1991·Surgical Neurology·R H Pudenz, E L Foltz
Jan 1, 1990·Pediatric Neurosurgery·M C da Silva, J M Drake
Jun 1, 1990·Journal of Neurosurgery·D Horton, M Pollay
Mar 1, 1988·Journal of Neurosurgery·E L Foltz, J P Blanks
Jan 1, 1985·Child's Nervous System : ChNS : Official Journal of the International Society for Pediatric Neurosurgery·W SerloL von Wendt
Mar 1, 1973·Journal of Neurosurgery·B KaufmanF E Nulsen
Jan 1, 1972·Acta Radiologica: Diagnosis·J W Loop, E L Foltz
Apr 1, 1982·Journal of Neurosurgery·M D Hyde-RowanF E Nulsen
Apr 1, 1995·Surgical Neurology·M S Turner
Jan 1, 1994·Current Biology : CB·T Wallimann
May 1, 1994·Child's Nervous System : ChNS : Official Journal of the International Society for Pediatric Neurosurgery·D A Watson
May 1, 1994·Child's Nervous System : ChNS : Official Journal of the International Society for Pediatric Neurosurgery·P KremerS Kunze
Mar 1, 1994·Chromosome Research : an International Journal on the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology·J G Gall

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Citations

Jul 20, 2004·Journal of Neurology, Neurosurgery, and Psychiatry·A EklundJ Malm
May 31, 2012·Fluids and Barriers of the CNS·Anders EklundJan Malm
Sep 27, 2007·Neurologia Medico-chirurgica·Akira Tsunoda, Chikashi Maruki
Jul 7, 2007·Neurosurgical Focus·Khalid H Kurtom, Gary Magram
Apr 5, 2007·Journal of Neurosurgery·Sherman C SteinSeema S Sonnad
Aug 15, 2006·Journal of Clinical Neuroscience : Official Journal of the Neurosurgical Society of Australasia·Colin C W Chong, James M van Gelder
Sep 15, 2005·Neurosurgery·Marvin BergsneiderNorman Relkin
Jun 17, 2003·Acta Neurologica Scandinavica·B LundkvistJ Malm
Jul 1, 2017·Acta neurochirurgica·Manuel GehlenMarianne Schmid Daners

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