Hydrocephalus Shunt System Glossary: Key Terms Explained

A glossary of hydrocephalus shunt system terms: VP and LP routes, fixed and adjustable valves, reservoirs, the siphon effect, kit contents and order codes.

A hydrocephalus shunt system diverts excess cerebrospinal fluid (CSF) from the brain’s ventricles or the lumbar space to another body cavity, usually the peritoneum, through catheters and a flow-controlling valve. This glossary defines the terms used around those systems, from valve types and pressure settings to kit contents and order codes.

Key takeaways

• A shunt system combines a valve that controls flow with catheters that carry CSF to another body cavity.
• Fixed-pressure valves have a set low, medium or high option; adjustable valves can be changed non-invasively.
• Depus, Defit and Decurve differ in body material, shape, size and mechanism.
• Code endings carry meaning: -VCK, -VACK and -ASD show the catheter kit and the antisiphon device.

Use it alongside the DESU page on hydrocephalus shunt systems. For catheter vocabulary such as inner diameter and radiopacity, see the neurosurgical catheter glossary.

What are the basic hydrocephalus terms?

• Hydrocephalus: a condition in which CSF builds up within the ventricles of the brain.
• Cerebrospinal fluid (CSF): the clear fluid that surrounds and cushions the brain and spinal cord.
• Ventricles: the fluid-filled spaces inside the brain.
• Lumbar space: the CSF-filled space around the nerve roots in the lower spine.
• Peritoneal cavity: the space inside the abdomen, the usual destination for shunted CSF.
• Shunt: an implanted system that diverts CSF from one place in the body to another.

What are the main shunt routes?

• Ventriculoperitoneal (VP) shunt: carries CSF from a ventricle to the peritoneal cavity. Depus, Defit and Decurve are all offered in VP kits.
• Lumboperitoneal (LP) shunt: carries CSF from the lumbar space to the peritoneal cavity. DESU LP kits use the Depus valve.
• Proximal and distal: relative directions along the system. The inflow side is usually called proximal; the peritoneal catheter is the distal catheter.

What do the valve terms mean?

• Shunt valve: the component that controls flow through the system.
• Opening pressure: the pressure at which a valve begins to allow flow.
• Fixed-pressure valve: a valve made at one pressure option. DESU fixed valves come in low, medium and high.
• Adjustable valve: a valve whose pressure level can be changed non-invasively. Depus offers adjustable valves in paediatric and adult sizes. Some sources call these programmable valves.
• 3 Pressure and 5 Pressure: adjustable Depus systems with three levels (low, medium, high) or five levels.
• Polysulfone valve: the Depus valve body material.
• Ruby ball and titanium spring: the Depus valve mechanism, which opens automatically under positive ventricular pressure.
• Flat-bottom valve: a valve with a flat underside. Defit has a flat-bottom silicone body in Ultra Small, Small and Regular, at 35, 40 and 45 mm overall length.
• Burr-hole valve: a valve shaped to sit at a burr hole, a small opening made in the skull. Decurve has a round silicone body, at 23 mm paediatric and 28 mm adult nominal diameter.
• Reservoir: a chamber in the shunt line. Decurve has one built in; on Depus it is optional, with flat-bottom and burr-hole options.
• Metal-free valve: a valve with no metal parts. Defit and Decurve contain no metal and are suitable for MRI and CT. Depus has a titanium spring.

Defit and Decurve are fixed-pressure families. Only Depus has adjustable versions.

What do the flow-control terms mean?

• Overdrainage: more CSF leaving through the shunt than intended.
• Underdrainage: too little CSF leaving through the shunt.
• Siphon effect: the pull that can occur when the peritoneal catheter moves from a horizontal to a vertical position, for example with a change of posture.
• Antisiphon device (ASD): an accessory that closes when the siphon effect occurs, to help prevent overdrainage. It is an option on Defit, Decurve and Depus kits.

The antisiphon device has its own article: how it counters the siphon effect.

What is in a shunt kit?

• Valve only: the valve supplied on its own, for a team that sources the catheters separately.
• VP shunt kit: a valve with a 23 cm ventricular catheter, a 120 cm peritoneal catheter, a stylet and a right-angled connector.
• LP shunt kit: a Depus valve with a lumbar catheter and a peritoneal catheter, with a 14 G Tuohy needle and a 0.018” guidewire.
• Ventricular catheter: the catheter that takes CSF from the ventricle. In these kits it has 1.3 mm inner and 2.5 mm outer diameter.
• Peritoneal catheter: the catheter that carries CSF into the peritoneal cavity. In these kits it has 1.1 mm inner and 2.5 mm outer diameter.
• Stylet: an accessory that supports guided, controlled advancement of the ventricular catheter during implantation.
• Right-angled connector: helps orient the ventricular catheter and connect it to the rest of the system.
• Y-type connector: a three-way accessory that joins two shunts to one peritoneal catheter, or gives a shunt two outlets or two inlets.
• Adjustment Kit: the Locator, Compass and Magnet used to locate, check and set an adjustable Depus valve. See the Depus Adjustment Kit.

What do the antibiotic options mean?

• Antibiotic-impregnated: the antibiotic is impregnated into the material and released in a controlled manner over 28 days. Impregnated catheters are orange; standard catheters are white.
• Valve-body impregnation: an option on Defit, Decurve and adjustable Depus valves in which only the valve body is impregnated.
• Semi-antibiotic kit: a standard valve with antibiotic-impregnated catheters.
• Full-antibiotic kit: an impregnated valve body with impregnated catheters.

How do you read order codes and label terms?

Fixed-pressure Depus codes show the pattern most clearly. Other families and sizes use their own code stems.

• Single-use: DESU shunt systems are supplied for single use.
• EO sterilised: sterilised with ethylene oxide, as DESU shunt systems are.
• Non-sterile: not supplied sterile, as with the reusable Depus Adjustment Kit.
• CE marked: carries the CE marking for the European market.
• ISO 13485: the international standard for medical device quality management systems.

Talk to a DESU product specialist

If a term on a label, tender or order code is not covered here, DESU product specialists can explain it. Write to sales@desu.tr, use the contact page, or request a quote.

Frequently asked questions

Are programmable and adjustable shunt valves the same thing?

In everyday use, yes. Both describe a valve whose pressure level can be changed non-invasively after it is in place. DESU uses the word adjustable, and adjustable Depus valves are set with the Depus Adjustment Kit.

What is the difference between a VP shunt kit and a VP catheter kit?

A VP shunt kit includes a valve. A VP catheter kit does not: it holds the ventricular and peritoneal catheters with a stylet and right-angled connector, and is a separate product.

Does this glossary replace the instructions for use?

No. It explains vocabulary only. Selection, implantation, adjustment and follow-up are decisions for the surgeon, guided by the instructions for use supplied with each product.

Related standards

• ISO 7197: Neurosurgical implants — Sterile, single-use hydrocephalus shunts and components
• ISO 11135: Sterilization of health-care products — Ethylene oxide
• ISO 13485: Medical devices — Quality management systems