In vitro performance and principles of anti-siphoning devices

Abstract

The tested ASDs were able to control the siphoning effect within a simulated shunt system to differing degrees. Future comparative trials are needed to determine the type of device that is superior for clinical application.

Patient Specific Hardware-in-the-Loop Testing of Cerebrospinal Fluid Shunt Systems

“…For the existing passive shunts, a large number of in vitro studies has already been performed to analyze their fluid dynamic properties, the effect of ICP pulsations and posture on these properties, and long-term stability [8]- [14]. In these studies, the intracranial and peritoneal pressures were assumed to be independent of CSF drainage.…”

A Technique for Treatment of Overdrainage in Ventriculoperitoneal Shunt

“…The postural alterations, particularly shifting from supine to upright, induced a "sucking" effect of CSF [18]. Several other causes evoked such as female sex, age, height, and respiratory cycle but not proved [15,17,[19][20][21][22]. Overdraining caused intracranial hypotension and collapse of ventricles, leading to subdural hematomas and craniosynostosis [3,23].…”

“…Overdrainage is due to insufficient valve pressures and siphoning of CSF during postural changes [2,5,[15][16][17]. The postural alterations, particularly shifting from supine to upright, induced a "sucking" effect of CSF [18].…”

Gravitational shunt valves in hydrocephalus to challenge the sequelae of over-drainage

“…Shunt Assistant (SA) is a technically improved additional valve like the GCA which can be combined with other differential pressure valves but has mostly been implanted in a preconfigured combination with a programmable differential pressure valve (proGAV) [9][10][11]. The Sophysa SiphonX (Sophysa SA, Orsay, France) is an analogous construction [12]. The Miethke Gravity-assisted valve (GAV) was a former variant of a combination of the SA and a nonprogrammable differential pressure valve in one small housing [13,14].…”

“…In vitro analyses of gravitational units allow investigation of flow and pressure characteristics mimicking in vivo performance [12,17]. The results of in vitro tests of all historically developed gravitational valves are extensively described by Aschoff [15].…”