An evaluation of the actual osv ii valve could not be performed because the device was discarded at the facility.However, lot number was provided; therefore, device history records were reviewed which revealed no anomalies that could explain the reported event.Failure analysis: the surgeon expressed concerns with the osv ii that he knows from a long time and is wondering whether the valve operating characteristics have changed: he feels that the ruby part may remain wedged with the membrane (diaphragm).A review of the manufacturing process since 2016 revealed no material change, no design change, no process change, no components supplier/design change: ruby pin and seat and the silicone elastomer diaphragm are unchanged: valve operating characteristics have not changed.Root cause: without actual device to analyze, complaints are unverifiable and exact root cause could not be determined.Overdrainage is a known, patient-related complication of valve therapy, as stated in the product instructions for use.Hydrocephalus shunt systems obstruction is known to be correlated to overdrainage: overdrainage leads to slit ventricle, blocking the ventricular catheter: then residues (from plexus choroid) can move along the shunt and block the valve mechanism.No further investigation nor corrective action is deemed required.
|