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A review of the manufacturing documentation associated with lot 18350005 presented no issues during the manufacturing process that can be related to the reported event.This device has been analyzed but the final, approved draft of the engineering report and its conclusion is not yet available.However, it will be submitted within 30 days upon receipt.Additional information is pending and will be submitted within 30 days upon receipt.
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Complaint conclusion: as reported, the delivery system and stent of a 7mm x 100mm 190cm s.M.A.R.T.Radianz vascular stent system broke apart while the operator used it on the patient.There were no reports of patient injury.The device was stored as per labeling.The device was opened in a sterile field.Additional information was requested but is not available.The device was returned for evaluation.A non-sterile ¿smart radianz 7x100 190cm¿ was received for analysis inside of a plastic bag.The device was unpacked for product evaluation.Upon inspection, it was observed that the outer sheath and inner shaft were separated approximately 172 cm from the distal end.The distal tip was also noted to be separated from the wire lumen, but neither the distal tip nor the stent were returned for analysis.The separated edge of the outer sheath was inspected using a vision system.Elongations and plastic deformations were observed on the material, which are commonly associated with separations caused by tensile and twisted overload.This indicates that the device was subjected to forces exceeding the material's yield strength prior to separation.The separated surface of the inner shaft was inspected with a vision system, revealing ductile dimples caused by micro void coalescence.As the part is pulled apart, the ductile material forms tiny bubbles (micro voids) in the material.When the part fractures into two sections, these bubbles break, leaving cup-like depressions.This characteristic is observed when materials are exposed to excessive mechanical stress, leading to fatigue failure.The separated edge of the wire lumen, where the distal tip was present, was inspected with a vision system.Elongations and plastic deformations were observed, indicating that the device was subjected to tensile and twisted forces exceeding the material's yield strength prior to separation.Dimensional analysis was performed to verify the correct outer diameter (od) and inner diameter (id) of the outer sheath and wire lumen.Measurements taken near the separation were found to be within specification.Dimensional analysis was also performed to verify the correct od of the inner shaft (core wire).Measurements taken near the separation were found to be within specification.A product history record (phr) review of lot 18350005 revealed no anomalies or non-conformances during the manufacturing and inspection processes that can be associated with the reported event.The reported ¿stent delivery system separated¿ was observed as the device was received in two pieces.The device was noted to have an ¿inner shaft separated¿ and ¿catheter tip separated¿ condition upon receipt for analysis.However, the exact cause of the reported events could not be conclusively determined.The distal portion of the catheter tip was not returned with the product for analysis.Microscopic analysis revealed evidence of elongations and plastic deformations associated with material tensile overload on the separated edges of the inner lumen and catheter tip.These findings indicate the device was subjected to tensile and twisted forces exceeding the material's yield strength prior to the separations that occurred.Based on the limited procedural information provided and condition of the returned device, vessel characteristics, along with procedural factors and handling of the stent delivery system contributed to the damages observed during product analysis.According to the instructions for use, which is not intended as a mitigation of risk, ¿stent placement: if resistance is encountered at any time during the insertion procedure, do not force passage.Resistance may cause damage to the stent or vessel.Carefully withdraw the stent system without deploying the stent.If resistance is felt when beginning deployment, do not force deployment.Carefully withdraw the stent system without deploying the stent.Insertion of guiding sheath or guide catheter and guidewire: a.Access the treatment site utilizing the appropriate accessory equipment compatible with the 6f (2.0 mm) delivery system.B.Place a 6f guiding sheath of an appropriate length (110cm for a 150cm long device and a 135cm for a 190cm long device) with an internal diameter of at least 2.2 mm.C.A brite tip radianztm guiding sheath is highly recommended.D.Place an.018¿ (0.46 mm) guidewire of sufficient length across the lesion to be stented via the guiding sheath or guide catheter.Introduction of stent delivery system: a.Ensure the safety lock is still in place.B.Advance the device over the guidewire through the hemostatic valve and guiding sheath to the lesion site.Note: if resistance is met during delivery system introduction, the system should be withdrawn, and another system should be used.The handle should not be rotated during insertion or removal.Caution: always use a guiding sheath for the implant procedure to protect puncture site.A guiding sheath of a 6f (2.0 mm) or larger size is recommended.Slack removal: a.Advance the stent delivery system past the lesion site.B.Pull back the stent delivery system until the radiopaque stent markers (leading and trailing ends) move in position so that they are proximal and distal to the target lesion site.C.Ensure the device outside the patient remains flat and straight.Caution: slack in the catheter shaft, either outside or inside the patient, may result in deploying the stent beyond the target lesion site.Post-deployment stent dilatation: a.While using fluoroscopy, withdraw the entire delivery system as one unit, over the guidewire, into the guiding sheath and out of the body.Remove the delivery device from the guidewire.Do not rotate the handle during withdrawal.Note: the guide wire lumen will be exposed upon removal of the device from the sheath.Be sure that distal tip is visible outside of the hemostasis valve before attempting to grasp the guide wire.B.Using fluoroscopy, visualize the stent to verify full deployment.If incomplete expansion exists within the stent at any point along the lesion, post deployment balloon dilatation (standard pta technique) can be performed.Note: only areas within the stent length should receive post-deployment balloon dilatation.C.Select an appropriate size pta balloon catheter and dilate the lesion with conventional technique.The inflation diameter of the pta balloon used for post-dilatation should approximate the diameter of the reference vessel.Remove the pta balloon from the patient.¿ neither the phr review, nor the product analysis suggests that the event experienced by the customer could be related to the manufacturing process.Therefore, no corrective or preventive action will be taken at this time.
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