Investigation: visual inspection: no significant deformations or damage of the valves were detected during the visual inspection.Permeability test: a permeability test has shown that both valves are permeable.Adjustment test: the progav 2.0 valve was tested and is adjustable to all specified pressures.Braking force and brake function test: the brake functionality test has shown that the brake function is fully operational and the braking force is within the given tolerances.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.Both valves are operating within acceptable tolerances.Results: no significant deformations or damage of the shuntsystem was detected during the visual inspection.Both valves were shown to be permeable and their opening pressures were operating within specifications.Additionally, we tested the adjustability as well as the brake functionality and brake force of the progav 2.0 valve.The valve operated as expected and met all specifications.Finally, we have dismantled the valves.Inside both valves, we have found slight build-up of substances (likely protein).Based on our investigation, we are unable to substantiate the claim of under-drainage.At the time of our investigation, the valves were operating within the specified tolerances.However, it is possible that the deposits observed inside the valve could have caused the malfunction in the past.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 shunt system met all specifications of the final inspection when released from christoph miethke gmbh & co.Kg.
|