Programmable valve shunts: are they really better?

Abstract

Programmable valve shunts allows selection of opening pressure of shunt valve. In the presented article, a unique complication pertaining to programmable shunts has been discussed. A 5-year-old boy who had tectal plate low grade glioma with obstructive hydrocephalus was managed with Codman programmable ventriculoperitoneal shunt. There was a spontaneous change in the opening pressure of the shunt valve leading to shunt malfunction. Routinely used household appliances produce a magnetic field strong enough to cause change in the setting of shunt valve pressure and may lead to valve malfunction. Other causes of programmable valve malfunction also discussed. MAnuSCRIPT Background: Programmable valve shunts are considered to be better than conventional fixed pressure valve shunts as they allow the selection of he opening pressure of the valve, which reduces the complications due to over/under drainage of the cerebrospinal fluid. Spontaneous changes in the set pressure, blockage and intrinsic malfunction of the valve are some causes of concern, apart from the cost.

Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions

“…Since Nulsen and Spitz first inserted a modern valve system in a hydrocephalus patient in 1949, fixed pressure valves have been used6). If the valve opening pressure does not match the CSF hydrodynamics of a patient, CSF over-drainage or CSF under-drainage symptoms can develop.…”

Radiation Risk Due to Shunted Hydrocephalus and the Role of MR Imaging–Safe Programmable Valves

“…There have been specific instances of these cases: A boy playing with toy magnets altered the valve settings on his shunt, 38 a man with a programmable shunt attempted suicide by using an electromagnet, 39 an iPad 2 altered the setting on the valve of a 4-month-old girl, 37 and the shunt setting of a 5-year-old boy was changed by a household electric appliance. 40 Of the programmable valves used in shunts today, only a few are MR imaging-safe. The effect of external magnetic fields of 3T MR imaging scanners on 5 programmable shunts that are available for use in hydrocephalus was investigated.…”

In-vitro Performance verschiedener Kombinationen von verstellbaren Differenzdruckventilen mit fixen Anti-Siphon-Devices unter Berücksichtigung der räumlichen Position

“…Es zeigten sich in neun von 50 Fällen (18 %) post-MRT-Verstellungen des Öffnungsdrucks und in sechs Fällen kam es zu Spontanverstellungen des Ventils (Belliard et al 1996). Pollack et al (1999) (Kataria et al 2012). Capitanio et al (2016) konnten in ihrer Studie mit dem programmierbaren Codman HakimMedos zeigen, dass ein 1,5-T MRT Öffnungsdruck-Verstellungen des Ventils verursacht (Capitanio et al 2016).…”

“…Abgesehen von Magnetfeldern gibt es weitere Ursachen, die zur Verstellung des Öffnungsdrucks in 2 % der Fälle beitragen. Diesbezüglich können Ventile verstopfen oder einzelne Komponenten im Ventilgehäuse dislozieren (Kataria et al 2012). Stumpfe Traumata verursachen durch mechanische Verformungen der Ventilkugel Fehl-Verstellungen (Kataria et al 2012)…”

“…Diesbezüglich können Ventile verstopfen oder einzelne Komponenten im Ventilgehäuse dislozieren (Kataria et al 2012). Stumpfe Traumata verursachen durch mechanische Verformungen der Ventilkugel Fehl-Verstellungen (Kataria et al 2012)…”