Application of clinically recorded ICP patterns--an extension of conventional shunt testing.
Various methods of laboratory testing are currently being used to explore the hydrodynamic properties of shunts. We constructed a novel shunt-testing rig with a human-like compliance to be able to subject shunts to in-vivo recorded ICP patterns. The human-like situation was realized with a pear-shaped glass container with a non-linear, third-order pressure/volume characteristic similar to the CSF system. The new device also allows conventional shunt testing. Shunt performance in conventional pressure/flow tests (linear compliance) was compared to tests with human-like compliance. No clinically relevant differences were seen. Clinically recorded ICP waves (Lundberg type A and B) were reproduced before and after shunt implementation. Shunt insertion reduced pressure in the A-wave pattern to slightly negative values. Reproducing B-waves, the shunt dampened wave amplitude and pressure decreased below the opening pressure of the valve. In conclusion, the presented device allows a standardized reproduction of ICP patterns. The effects of shunt implantation can be studied.
Schuhmann
M U
MU
Department of Neurosurgery, Hannover Medical School, Germany. mschuh@gmx.de
Engel
M
M
Runge
L
L
Samii
M
M
Brinker
T
T
D002555:Cerebrospinal Fluid / Q000502:physiology; D002557:Cerebrospinal Fluid Shunts; D006801:Humans; D007427:Intracranial Pressure; D008959:Models, Neurological