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Visual inspection: during the investigation, no significant deformations or damage of the valves were determined.Permeability test: a permeability test has shown that the valve has a blockage.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 valve is tested in both the horizontal as well as the vertical positions.Because the valve is not permeable, a computer controlled test is not possible.Internal inspection : after dismantling of the valve, visible deposits were found in the gav 2.0.Results: based on our investigation results, we can determine a clogging of the valve.The visible deposits in the valve may have led to the functional impairment.Deposits caused by substances naturally present in the patient's body, such as organic matter, blood or tissue particles, are among the known and unavoidable risks and side effects of hydrocephalus therapy.Even small amounts of organic material can affect the integrity of the valve.We would also like to point out that the condition of the product may be affected by the period between the explantation date and the release of the product.Long storage times may additionally affect the investigation results.No further regulatory actions are required from our point of view.
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