Analysis: the icast covered stent delivery system was returned from the field and evaluated.Upon initial inspection the stent was no longer crimped on to the balloon of the stent delivery system.There were no signs of damage to the stent delivery system and the balloon was still in is folded position.The balloon had the impressions of the stent frame clearly visible indicating that the stent had been crimped properly.The stent was inspected and found to have two stent end crowns completely folded back upon itself.The damage appears to have either been caused by getting hung up on the bare metal stent the physician was relining with the icast covered stent or while attempting to pull the stent back through the introducer sheath.The instructions for use specify the following: ¿do not attempt to pull an unexpanded stent back through the bronchoscope or endo-tracheal tube since dislodgement of the stent may result (refer to removal of an unexpanded stent).Removal of an unexpanded stent should it become necessary to remove the icast covered stent from the lumen prior to deployment and a bronchoscope or endo-tracheal tube is being used, do not withdraw the icast covered stent back into the bronchoscope or endo-tracheal tube after the device is fully introduced.To remove the icast covered stent prior to deployment, the icast covered stent/balloon catheter should be withdrawn until the proximal end of the icast covered stent is aligned with the distal tip of the bronchoscope or endo-tracheal tube.The icast covered stent/balloon catheter, guidewire and bronchoscope or endo-tracheal tube, should then all be removed as one unit.After removal, the icast covered stent should not be reused.¿ a full review of the catheter lot history records was performed.Below is an overview of the quality and performance criteria that every lot of icast covered stent systems is tested to.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 (6fr/7fr) depending on size.¿ 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 10 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).In addition to the final lot qualification testing there are multiple in process inspections conducted that include the following: ¿ balloon hole skive dimensional verification.¿ stent securement testing.¿ proximal balloon weld tensile testing as detailed above.¿ distal tip tensile testing.¿ catheter leak check.A review of the catheter stent retention data obtained from this testing indicates that the lowest stent dislodgement force was 9.6 newtons.This value is well above the =2.9 newton requirement.Conclusion: based on the investigation atrium medical corporation cannot conclude that the device was faulty.It is likely that the stent was damaged and dislodged when the stent was caught on the previously deployed stent and when the stent was attempted to be pulled back through the introducer sheath.
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