Clinical descriptionCodman® CERTAS™ Plus is a programmable, implantable shunt valve that provides a constant intraventricular pressure and drainage of cerebrospinal fluid (CSF) for the management of hydrocephalus. The operating pressure can be read and adjusted non-invasively, transcutaneously, over the course of the patient’s evolution — without further surgery — using the dedicated tool kits (Codman CERTAS® Tool Kit or CERTAS™ Plus Electronic Tool Kit).
The valve offers 8 pressure settings: 7 settings between 25 and 215 mmH₂O (25, 50, 80, 110, 145, 180, 215) to optimize drainage, plus the 8th "Virtual Off" setting, with a minimum operating pressure greater than 400 mmH₂O, which limits flow through the valve. The adjustable ruby bushing, ball & seat mechanism and the integrated reservoir are complemented by a tantalum ball coupled to a magnet, which allows the setting to be read on radiography as well (with the X-ray overlay tool). The valve is designed to resist unintended changes of the setting caused by external magnetic fields, including MRI up to 3 Tesla (confirmation of the setting after an MRI examination is recommended). Three housing models are available: Inline Regular (for most patients), Inline Small (low profile, with connectors oriented toward the skull to reduce local tissue tension), and Right Angle (for placement in the burr hole).
For additional control, the valve can be integrated with the SiphonGuard® anti-siphon device, which reduces the risk of overdrainage: at normal flow both pathways (primary and secondary) are open, and at excessive flow the primary pathway closes, the secondary remaining open to reduce the drainage rate. The rigid polyethersulfone housing makes it position-independent and unaffected by encapsulation or external pressure. To reduce the risk of infection, the system is also available with the Bactiseal® catheter — impregnated (not coated) with two slow-release antibiotics, rifampicin and clindamycin — which reduces gram-positive bacterial colonization of the catheter surface for up to 50 days. CERTAS™ Plus is the only Codman® programmable valve available with a unitized antimicrobial catheter.
