Shunt Reservoirs: Decurve Built-In, Depus Optional
Shunt reservoirs explained: what the chamber is for, the reservoir built into the Decurve valve, optional Depus reservoirs, and how to specify each on an order.
A shunt reservoir is a small chamber in a shunt system that gives the clinical team a defined point of access beneath the scalp. In DESU shunt systems, the Decurve valve has a reservoir built in, while Depus systems take one as an option, in flat-bottom or burr-hole form.
Key takeaways
- A shunt reservoir is a chamber in the system that gives the clinical team a defined point of access.
- The Decurve valve has its reservoir built in, so there is no separate reservoir to specify.
- On Depus systems the reservoir is added according to clinical need, with flat-bottom and burr-hole options.
- Depus order codes carry no reservoir marker, so state the reservoir on the order line.
Whether and how any reservoir is accessed in a given patient is set out in the instructions for use and decided by the treating team.
What is a shunt reservoir?
A shunt moves cerebrospinal fluid from the ventricles to another body cavity, most often the peritoneum, through a ventricular catheter, a valve and a distal catheter. The valve controls the flow. A reservoir is an additional chamber on that route, placed under the skin.
The appeal of a reservoir is access. Because it lies under the scalp rather than deep in the body, it can give the team a known place to reach the fluid in the system, for example when CSF needs to be sampled or the shunt needs to be assessed. The rules for doing so, including whether a particular reservoir may be punctured at all, belong to the product’s instructions for use and the hospital’s protocol.
What does a reservoir not do?
It helps to separate the reservoir from the components it sits beside, because the three are often discussed together:
- The valve sets the pressure behaviour. On Decurve and fixed-pressure Depus, that means low, medium or high; on adjustable Depus, a setting made with the Depus Adjustment Kit.
- The antisiphon device is the component intended to counter the siphon effect when the peritoneal catheter moves from horizontal to vertical.
- The reservoir provides a chamber in the system and leaves those two jobs to the other components.
How is the reservoir built into the Decurve valve?
Decurve is DESU’s fixed-pressure burr-hole valve: a round body with a reservoir. It comes in two sizes, a paediatric valve of 23 mm nominal diameter and an adult valve of 28 mm, each with low, medium and high pressure options. It is made of polypropylene and silicone elastomer and contains no metal.
Because the reservoir is part of the valve, there is nothing extra to select or assemble. A team choosing Decurve gets the reservoir with every valve, including the standard, semi-antibiotic, full-antibiotic and antisiphon configurations. The placement logic of a burr-hole valve compared with a flat-bottom one is covered in Flat-Bottom vs Burr-Hole Shunt Valves.
How does the optional Depus reservoir work?
Depus takes the opposite approach. With its polysulfone valve, a reservoir can be used optionally in Depus shunt systems, in flat-bottom and burr-hole options.
This applies to both forms of fixed-pressure Depus kit. Ventriculoperitoneal kits contain the valve, a 23 cm ventricular catheter, a 120 cm peritoneal catheter, a stylet and a right-angled connector, and an antisiphon device and reservoir can be added according to clinical need. Lumboperitoneal kits contain the valve, a lumbar catheter, a peritoneal catheter, a 14 G Tuohy needle and a 0.018” guidewire, with the same two optional additions.
Which reservoirs do adjustable Depus kits offer?
Adjustable Depus kits work slightly differently: the silicone reservoir is part of the kit contents, and the system is offered with four silicone alternatives:
- Adult flat-bottom reservoir
- Paediatric flat-bottom reservoir
- Adult burr-hole reservoir
- Paediatric burr-hole reservoir
The choice therefore has two parts, patient size and reservoir shape, on top of the choice between paediatric and adult adjustable valves. How the adjustable valve itself is chosen against a fixed one is covered in Fixed-Pressure vs Adjustable Shunt Valves.
How do the DESU shunt families compare?
| Shunt family | Reservoir | Form |
|---|---|---|
| Decurve | Built into the valve | Part of the round burr-hole valve; 23 mm or 28 mm |
| Depus fixed-pressure VP | Optional, by clinical need | Family includes flat-bottom and burr-hole options |
| Depus LP | Optional | Family includes flat-bottom and burr-hole options |
| Depus adjustable VP | In the kit contents | Four silicone alternatives, adult and paediatric |
| Defit | None | Flat-bottom valve |
The practical reading is simple. If a built-in reservoir is wanted on a fixed-pressure, metal-free valve, Decurve provides it. If the team prefers a separate reservoir with a choice of shape, or an adjustable valve, Depus is the family to look at.
How is a reservoir specified on an order?
For Decurve, the valve code is enough. DCP-M-VCK is a medium-pressure paediatric Decurve with a VP catheter kit, and DCA-M-VCK is the adult equivalent; no reservoir line is needed.
For Depus, take more care. Codes such as DP-M-VCK (fixed-pressure VP kit), DP-A-VCK (adjustable paediatric) and DPA-A-VCK (adjustable adult) mark the pressure, the kit type and, with “-ASD”, an antisiphon device. They carry no marker for a reservoir, so a useful order line states three things in words:
- Whether a reservoir is required.
- Its shape: flat-bottom or burr-hole.
- Its size: adult or paediatric.
Our product specialists will confirm how that reservoir is supplied for your configuration, so that it is neither missing from the delivery nor ordered twice.
Talk to a DESU product specialist
For help specifying a Decurve or Depus configuration, or to confirm how a reservoir is supplied for your order, write to sales@desu.tr, use the contact page, or request a quote.
Frequently asked questions
Does a Defit valve have a reservoir?
No. Defit is a flat-bottom silicone valve in Ultra Small, Small and Regular sizes with low, medium and high fixed pressures. If a reservoir matters for a case, Decurve and Depus are the DESU families that have one.
Is the Decurve reservoir metal-free?
Yes. The whole Decurve valve contains no metal. It is made of polypropylene and silicone elastomer and is suitable for MRI and CT.
Can a reservoir and an antisiphon device be used in the same Depus kit?
Both are options that can be added to Depus kits according to clinical need. The final configuration is the surgeon’s decision, and we can confirm how the two are supplied together.
Does a reservoir change the pressure category of the shunt?
The low, medium or high category belongs to the valve, so the pressure decision and the reservoir decision are made separately.
Related standards
- ISO 7197: Neurosurgical implants — Sterile, single-use hydrocephalus shunts and components
- ISO 13485: Medical devices — Quality management systems