MAUDE Adverse Event Report: COOK IRELAND LTD ZILVER 518 VASCULAR SELF-EXPANDING STENT; NIO STENT, ILIAC

Catalog Number	ZIV5-18-125-10-60
Medical Device Problem Code	Activation, Positioning or Separation Problem (2906)
Health Effect - Clinical Code	No Consequences Or Impact To Patient (2199)
Date of Event	09/22/2016
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
Pma/510(k) # p050017 s002 and s003.The 1x ziv5-18-125-10-60 device of lot c1128125 was implanted in the patient and is not available for evaluation.With the information provided, a document based investigation was provided.Additional information was received from the sales representative.The complaint device was advanced over a cook aes wire guide.There was no indication of deformation or compression post deployment.The physician reported that the patient anatomy was not unusually calcified or tortuous.The wire guide and delivery system did not encounter resistance when advancing to the target location.The physician confirmed that the handle was pulled towards the hub during deployment.Imaging of the implanted stent sent to a clinical specialist for evaluation.The following response was received.Findings: seven angiographic images photographed off a monitor are provided along with the complaint report.All images demonstrate a concertinaed zilver stent deployed in a severely irregular right external iliac artery (eia) stenosis.Four of the images demonstrate angioplasty during and or after what was labelled as an 8x40mm balloon.The balloon measures an 8x20mm balloon rather than a 40mm long balloon.Two sheaths or a sheath and guiding catheter were present.The access sheath was much larger than necessary to angioplasty and stent the lesion.It was at least 10 if not 12 french.The lesion was stented with a second zilver stent that was positioned to cover the eia distal to the concertinaed stent.One image also suggests a rosen wire.This would be a rather odd wire of choice for this lesion.A more conventional wire selection would have been a benson or glide advantage.The presence of the rosen suggests that wire access across the concertinaed stent was lost at some point and then re-established with a rosen wire.The j-shape of the rosen wire is less likely to transgress the interstices of a freshly implanted stent.Implantation of a second stent relieved mild residual stenosis caused by the concertinaed stent.The complaint report's mention of a dissection may explain the presence of the large sheath along with the angiographic finding of a small unusually long and limited branching vessel originating proximal to the eia.This vessel has appearance of the ima but this could be a narrowed internal iliac artery, an iliolumbar artery or even a dissected left cia artery.Consequently, the large sheath may have been left over from treatment of an aortic dissection, not treatment of a post angioplasty dissection.Impression: the imaging confirms a concertinaed zilver stent.The implantation position of the second stent demonstrates that the stent's distal end landed short of its intended target.This can be the result of unintended forward delivery system pressure however given the straight anatomy this is unlikely.In severely irregular lesions such as this, stents can be extracted by irregular plaque.Other features of this case suggest either delivery system entrapment upon retrieval or balloon entrapment.First, an access sheath and a guide catheter/sheath were likely present and the access sheath was far larger than necessary to implant a zilver stent.Second, the balloon was a 8x20mm balloon, not a 8x40 balloon as annotated on the provided images.Finally the presence of a rosen wire suggests loss of wire access across the implanted stent.Significant findings relative to the patient's anatomy were not observed.The lesion was severely irregular but generally straight.Significant findings relative to the disease state were not observed.Significant findings relative to the use of the device were observed.An additional guide catheter or sheath was present and the primary access sheath was much larger than needed to implant the zilver stent.These observations suggest possible stent entrapment.Significant findings relative to the design or performance of the device were observed.The stent did deploy with its distal end concertinaed into its proximal end.This could have been secondary to stent extraction from the delivery system.However other findings suggest stent entrapment after deployment as the cause.Cause of adverse events was not observed.The customer complaint is confirmed as the image review observed that the stent was concertinaed/shortened.Possible causes for this occurrence could include forward pressure on the delivery system during deployment, stent extraction by irregular plaque or stent entrapment due to the presence of an additional guide catheter or sheath and the primary access sheath being much larger than needed.The evaluating clinician stated that on review of the images from the procedure, a second stent was placed inside the concertinaed stent and the eia more distal.This stent relieved mild residual stenosis caused by the concertinaed stent.The image review confirmed that the first stent did deploy with its distal end concertinaed into its proximal end.This could have been secondary to stent extraction from the delivery system.However other findings suggest stent entrapment after deployment as the cause.The evaluating clinician stated that the root cause of the adverse events was not observed.Therefore, as the conditions of use cannot be replicated in the laboratory, a definitive root cause cannot be determined.Prior to distribution all zilver 518 devices are subject to visual inspection and functional checks to ensure device integrity.A review of the relevant manufacturing records revealed no discrepancies that could have contributed to this complaint.Upon review of complaints, this failure mode has not occurred previously with this lot number.Based on the information available to date, there is no evidence to suggest that there are any manufacturing issues associated with this lot number.According to the initial reporter, an additional stent was implanted as a result of this occurrence.The patient did not experience any adverse effects due to this occurrence.Quality engineering will continue to monitor complaints of this nature for potential emerging trends.
Event or Problem Description
It was reported that upon deploying the stent, which was supposed to be a 10x60 zilver 518, the physician and the staff noticed it looked more like a 30mm stent, especially when ballooning it with an 8x4 balloon.Another 10x60 zilver stent was used (lot #c1232735), and when put inside the previously placed one, it was twice as long.No product will be returned.Images were provided.

• Brand Name: ZILVER 518 VASCULAR SELF-EXPANDING STENT
• Common Device Name: NIO STENT, ILIAC
• Manufacturer (Section D): COOK IRELAND LTD; o halloran road; limerick
• MDR Report Key: 6245039
• Report Number: 3001845648-2017-00008
• Device Sequence Number: 19054874
• Product Code: NIO
• UDI-Device Identifier: 10827002437927
• UDI-Public: (01)10827002437927(17)180714(10)C1128125
• Combination Product (Y/N): N
• Initial Reporter State: CA
• Initial Reporter Country: US
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2016
• Reporter Type: Manufacturer
• Report Source: company representative,health
• Initial Reporter Occupation: Other
• Type of Report: Initial
• Report Date (Section B): 12/15/2016

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Catalogue Number: ZIV5-18-125-10-60
• Was Device Available for Evaluation?: No
• Was the Report Sent to FDA?: No
• Distributor Facility Aware Date: 09/22/2016
• Event Location: Hospital
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 12/15/2016
• Initial Report FDA Received Date: 01/12/2017
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1