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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 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 clinical claim of underdrainage, the opening pressure is measured using a miethke computer controlled testing apparatus which simulates a cerebrospinal fluid flow.The progav 2.0 valve is operating within acceptable, the shuntassistant 2.0 is operating minimal not within the accepted tolerances.Results: first, we performed a visual inspection of the progav 2.0 shunt system.No significant deformations or damage of the valves were detected during the visual inspection.Next, we tested the permeability, adjustability, and opening pressure of the valve, as well as the brake functionality and brake force.The opening pressure of the shuntassistant 2.0 was out of tolerance, but all other specifications were met.The opening pressure was minimal lower than expected, shows an increased flow of liquid.Finally, we have dismantled the valves.Inside the progav 2.0 valves we have found slightly build-up of substances (likely protein), but there were no visible deposits observed in the fixed pressure valve.Based on our investigation, we are unable to substantiate the clinical claim of under-drainage.How the above-mentioned functional impairment occurred is not clear to us at the time of the investigation.Despite the lack of significant deposits, it is possible that even non-visible or small amounts of build-up could have led to a temporary compromise of the valve and to the observed malfunction.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.No further regulatory actions are required from our point of view.
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It was reported that there was a flow problem of a progav 2.0 shuntsystem.Patient information: age: (b)(6).Weight: (b)(6), height: 180 cm, gender: male, date of implantation: (b)(6) 2019, date of removal: (b)(6) 2021.
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