Related Experiment Video
Updated: Jun 24, 2026
Neuronavigation and Laparoscopy Guided Ventriculoperitoneal Shunt Insertion for the Treatment of Hydrocephalus
Published on: October 14, 2022
Gravitational valves in supine patients with ventriculo-peritoneal shunts
Martin H Deininger1, Astrid Weyerbrock
1Department of Neurosurgery, University of Freiburg Medical School, Breisacher Str. 64, D-79106 Freiburg, Germany. martin.deininger@uniklinik-freiburg.de
Background:
In the subgroup of bedridden hydrocephalic patients with ventriculo-peritoneal shunts and gravitational valves, we occasionally observed persisting hydrocephalic complaints even when mechanical or infection-related obstruction was excluded.
Methods:
To investigate the cause of these hydrocephalic symptoms, in vitro and in vivo analyses were used to determine valve opening, intra-abdominal and hydrostatic pressure of an Aesculap-Miethke 10/40 cm H2O gravitational valve at different angles of upper body and head inclination.
Findings:
Since hydrostatic pressure is lacking, the resulting intra-ventricular pressures are shown to peak up to 27 cm H2O in supine patients with head, but not upper body inclined.
Conclusions:
We conclude that in the subgroup of bedridden patients with ventriculo-peritoneal shunts and gravitational valves, upright posture is a prerequisite for proper cerebrospinal fluid drainage.
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