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Visual inspection: during the investigation, no significant deformations or damages of the valves were determined.Permeability test: a permeability test has shown that both valves are permeable.Computer controlled test: to investigate the claim of under-drainage, the opening pressure is measured using a miethke computer controlled testing apparatus which simulates a cerebrospinal fluid flow.The valves are tested in both the horizontal as well as the vertical position.The result shows that the progav 2.0 operates within the accepted tolerances in the horizontal position.However, the m.Blue does not operate within the specified tolerances in the vertical position.A tendency for an accelerated outflow of the m.Blue could be determined.Adjustment test: the valves were tested and both valves are adjustable in all pressure settings.Braking force and brake function test: the brake functionality test has shown that the brake function operates as expected and the braking force is within the given tolerance.Internal inspection: after dismantling of the valves, organic deposits were found in m.Blue.Results: based on our investigation results, we can determine a tendency towards accelerated flow at the m.Blue.The deposits, some of which are visible in the valve, have led to the change in the flow rate.We cannot detect any functional deviations or other anomalies on the progav 2.0 and the control reservoir.The components work within the specifications.Deposits caused by natural substances in the body, such as protein, blood or tissue particles, are among the known and unavoidable risks and side effects of hydrocephalus therapy.Even small amounts of organic deposits can impair the integrity of the valve.When valves are opened, it is possible to see a large part of the interior.However, there are areas that cannot be examined visually.These areas may contain organic deposits that can impair the function.It is also possible that deposits are already flushed out when the valve is flushed on the test bench.We can exclude a defect at the time of release.The shunt system met all specifications of the final inspection when released from christoph miethke gmbh & co.Kg.No further regulatory actions are required from our point of view.
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