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A non-sterile enterprise vrd and delivery unit was received inside of a plastic bag.The original box of the product and original pouch both labeled with lot # 10222387 were received.The delivery wire, introducer tube, gauze, and stent were received inside of pouch.The stent was received deployed inside of the gauze.On the delivery wire unraveled stretched and wave conditions were observed to the length of the distal tip section.No damages were observed on the introducer tube.The microcatheter involved was not received.Functional analysis cannot be performed due to device received condition (unraveled stretched at distal section and fractured condition at 2cm from distal tip end).Lake region medical reviewed the device history records relative to the manufacturing, inspecting and packaging of lot 10222387.The device history record review also included a review of the certificate of conformance received from specialty coatings systems and nitinol devices and components, along with lake region medical¿s internal receiving inspection records for the stents issued to the complaint lot.The history records indicate this product was final inspection tested at lake region medical and was determined to be acceptable.The delivery wire and stent were inspected under vision system and a fractured condition was observed in the core wire from delivery wire at 2 cm from distal tip end; dried saline solution residue was observed on distal tip section.No damages were observed on the stent.The delivery wire was sent for scanning electron microscope (sem) analysis in order to determine the cause of the fracture in distal tip section condition found during analysis.Results showed that the wire presented evidence of corrosion at proximal section of the fracture and distal section of the guidewire.This condition was also observed at coil wire.It cannot be determined how the corrosion has been induced on this sample.No other anomalies were found during sem analysis.Additional analysis was performed by lake region, with additional investigation by codman cnv, and it was concluded that prolonged exposure to corrosive saline solution and blood was the most likely cause of the corrosion found.Historically, the time the specimen is exposed to the corrosive blood and saline is from 1 to 20 weeks (the time from of the clinical event to the device being analyzed in the failure analysis laboratory).The failure reported by the customer that the stent delivery system did not advance through the microcatheter cannot be properly evaluated as a functional test could not be performed due to damages observed in the device (fractured in delivery wire and unraveled stretched).The exact cause of reported event as well as the wave conditions observed on the delivery wire could not be conclusive determined; however, per analysis and dhr review, procedural factors might have contributed with the cause of the failures reported by the customer.Since it was reported that neither the stent, nor the stent delivery system appeared damaged by the customer while in the clinical setting and immediately following the clinical event, the corrosion presented by the returned specimen were most likely post-procedural.Sem analysis was executed in order to determine the cause of the fractured condition found during analysis, results showed that the wire presented evidence of corrosion at proximal section of the fracture and distal section of the guidewire.This condition was also observed at coil wire.It cannot be determined how the corrosion has been induced on this sample.No other anomalies were found during sem analysis.Additional analysis was performed by lake region and they concluded that prolonged exposure to corrosive saline solution and blood was the most likely cause of the corrosion found.An internal risk assesment was opened address this issue.
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