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The returned product was subjected to a technical analysis and the corresponding production documentation was reviewed to establish whether a deviation from the manufacturing process could be the cause for this event.The technical investigation of the returned instrument revealed that the stent severely deformed and elongated at its distal end.Microscopic analysis revealed stent imprints on the exposed balloon surface, indicating that the deformed struts were initially crimped on the balloon.Dried contrast medium was found in the inflation lumen as well as in the balloon lumen up to the position of the deformation.The stent protector was not returned for analysis.A reference protector cap could not be slid over the deformed struts without bending them further.Since it was not possible to apply a reference protector cap over the deformed struts without bending them further, it can be excluded beyond reasonable doubt that the damage was already present on delivery of the instrument.Review of the production documentation confirmed that the instrument was manufactured according to specifications and passed all in-process and final inspections.As a part of final inspection every stent system undergoes visual inspection to ensure correct embedding and homogeneous crimping of the stent.The device in question was manufactured according to specifications and successfully passed all inprocess controls as well as the final inspection.Based on the conducted investigations, no manufacturing or material related root cause could be determined.The complaint event is most likely related to the handling during the preparation for the intervention (i.E.Application of negative pressure prior to the placement across the target lesion), which is warned against in the ifu.
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