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Investigation: visual inspection: no significant deformations or damage of the valve were detected during the visual inspection.Permeability test: a permeability test has shown that the valve is permeable.Computer controlled test: to investigate the claim of over-drainage, the opening pressure is measured using a miethke computer controlled testing apparatus which simulates a cerebrospinal fluid flow.The results show that the valve with a value of 25cmh2o is not operating within the acceptable tolerance of 25 cmh2o +4/-2 cmh2o in the vertical position.Internal inspection: after the dismantling of the valve, some deposits were found in the shuntassistant.Results: based on our investigation, we confirm that the valve shows an increased flow of liquid, likely due to the deposits observed inside the valve.As described in scientific literature, the problem encountered is one of the known, inevitable risks of hc-therapy by shunt implants.We can exclude a defect at the time of release.The valve met all specifications of the final inspection when released from christoph miethke (b)(4).No further regulatory actions are required from our point of view.
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