Authors: Jordan L. Davies, MD
40% of ventricular shunts fail within the first 2 years. Catheter breakage and occlusion are the most commonly reported mechanisms. This project aims to overcome those failures of conventional shunting devices, by the use of a catheter-free, passive, miniaturized valve implanted intracranially to act as an absorption bypass.Methods: An in-vitro, bench-top model replicating physiologic conditions of hydrocephalus was utilized to test the hydrodynamic properties of a 3D printed valve. The self-sealing valve has two membranes, which isolate one from the other in a closed state. When internal pressure rises above the valve opening pressure, the membranes separate to expose the perforations through which fluid flows.
A basic flow response of the valve was measured in a bench-top fluid circuit setup. The valve showed a highly directional hydrostatic response with little reverse flow, measured at about 0.7ul/min. The valve opening pressure was about 30 mmH2O.
This proposed 3D printed valve demonstrated favorable hydrostatic characteristics for CSF drainage, with an opening pressure of about 30 mmH2O, minimal reverse flow, negligible clogging, and simple design. Further studies will need to assess the viability of the utilization of this type of device in vivo.