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Engineering analysis: the icast was removed from the packaging and inspected to determine the cause of the complaint.The delivery system was decontaminated and inspected for damage.There was damage to the shaft approximately 30cm from the inflation manifold.The damage is indicative of a device that has been forced during insertion creating an accordion effect of the shaft.The stent was not returned with the delivery catheter.The introducer sheath used in this procedure was not returned.The returned device balloon surface was evaluated to determine if the stent was crimped properly during manufacturing.The crimped stent impressions were clearly visible indicating that the stent was properly crimped during manufacturing.Engineering summary: a full review of the catheter lot history records for the device in question was performed.The records indicate that this lot of catheters passed atriums final lot qualification testing.This inspection requires that the catheter lot must pass the following: · ability of the stent and delivery system to be passed through the labeled introducer sheath.· ability to deploy the stent at nominal pressure (8atm).· ability to withdraw the deflated balloon catheter back through the labeled introducer sheath.· ability of the delivery system to withstand 5 inflate/deflate cycles at the rated burst pressure (12atm) without leaks or failures.· balloon burst testing.The balloon must burst over the rated burst pressure specified on the label (12atm).· manifold to shaft tensile testing.Samples when tensile tested must not break or separate below 3.37lbs.Result: all 59 quality inspection samples passed this final inspection without any non-conformances noted during the final lot qualification testing related to the stent.None of the 59 samples tested had any stent movement while passing the device through the introducer sheath.Other potential causes may also be considered but cannot be verified.In many cases stent dislodgement has been when operators grasp and tug on the stent to verify stent retention.This technique can dislodge the stent if too much force is applied.In some cases we have also learned that operators mistake the white eptfe covering on the stent for a removable sheath and try to pull it off.Conclusion: based on the details of the event and the successful lot qualification test data, atrium can find no fault with the device and or lot of stent delivery systems in question.Clinical evaluation: obstruction can be caused by anatomical process, infectious process or mechanical process including an unopposed stent interfering with the flow of air or blood.The instructions for use state, "special care should be taken to ensure that the appropriate size device, guide wire, compatible bronchoscope and endotracheal tube are selected prior to introduction.Native lumen dimensions must be accurately measured, not estimated." there are several possibilities that can cause stent dislodgement including but not limited to an incorrectly sized sheath for the product, advancement of the stent through challenging anatomy and by forcefully advancing the device across calcified lesions.
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