MAUDE Adverse Event Report: COOK INC ZENITH FLEX WITH SPIRAL-Z TECHNOLOGY AAA ENDOVASCULAR GRAFT ILIAC LEG; MIH SYSTEM, ENDOVASCULAR GRAFT, AORTIC ANEURYSM TREATMENT

Model Number	G55241
Medical Device Problem Code	Kinked (1339)
Health Effect - Clinical Code	Stenosis (2263)
Date of Event	02/14/2018
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
(b)(4).This report includes information known at this time.A follow up report will be submitted should additional relevant information become available.
Event or Problem Description
It was reported that an (b)(6), male patient underwent an endovascular aneurysm repair (evar) to treat an abdominal aortic aneurysm (aaa) on (b)(6) 2017.The latest computerized tomographic angiography (cta) shows partial stenosis of the right trouser leg and leg extension.As reported, the doctor plans to reline the zenith flex with spiral-z technology aaa endovascular graft iliac leg with another manufacturer's balloon expandable covered stent.According to the initial reporter, the patient did not experience any additional adverse effects due to this occurrence.
Additional Manufacturer Narrative
Additional information received.
Event or Problem Description
There was no resistance noted at implantation.The grafts went up very smoothly.One coda 32 balloon was used prior to the final angiogram.Ballooning was performed at the proximal sealing stent of the zalb and the entire length of both legs.A 60cc syringe was used with 10ml of contrast and 20ml of saline.The physician did not measure the volume of solution utilized at each segment.Reportedly they inflated until it felt ¿firm¿.The doctor has since relined with another manufacturers' balloon expandable covered stent and is happy with the result.
Additional Manufacturer Narrative
Additional information was received on 24may2018.Concomitant medical products: correction ¿ the device was not returned.Imaging was received on 14mar2018.The actual complaint device was not returned.Without the complaint device, a physical investigation was not able to be completed.A documentation based investigation was performed.A review of provided imaging, the device planning and sizing worksheet, device history record, instructions for use, manufacturing instructions and quality control data was conducted.A preoperative case planning document and a 2-month postoperative computerized tomography (ct) scan study were provided.The preoperative case planning and sizing document was reviewed.The reconstructed images attached to the document show mild tortuosity of the right iliac system and moderate to severe tortuosity of the left iliac system.The 2-month postoperative ct study, dated 1/24/18, was reviewed.An aortic endograft (zalb 24 x 98 mm) is placed for repair of an infrarenal abdominal aortic aneurysm (aaa).The proximal graft is just below the lower left renal artery.The main body device appears widely patent and measures 19.5 mm in diameter, proximally.There may be some contrast outside the endograft, tracking from anterior to lateral within the sac.A patent inferior mesenteric artery and patent lumbar artery are adjacent to this level.Non-contrast images would be needed to compare to determine if this is a type 2 endoleak or artifact within the aaa sac.There is focal thrombus formation and a >50% stenosis in the mid zsle leg at the junction of the distal ipsilateral limb.The zsle leg proximally and distally appears widely patent.There is no kinking or angulation noted in the area of stenosis.The left iliac leg (zsle 16 x 56 mm) has 28 mm overlap within the contralateral limb and seals in the distal left common iliac artery with no distal endoleak.The iliac leg appears widely patent and measures 13.1 x 13.4 mm in diameter, distally.Both iliac legs are closely aligned proximally within the main body device.Impressions of the imaging reviewer: an infrarenal aaa is repaired with a zalb 24 x 98 mm main body device, a zsle 20 x 56 mm ipsilateral iliac leg on the right, and a zsle 16 x 55 mm contralateral iliac leg on the left.There may be a type 2 endoleak related to patent inferior mesenteric artery (ima) and lumbar arteries.There is >50% stenosis of the mid right zsle leg related to thrombus formation, focally, at the junction of the distal ipsilateral limb.There is no angulation or kinking noted at this level.The 20 mm zsle leg is placed 53 mm above the distal ipsilateral limb, causing a 15 mm length of the flared segment to overlap within the 11 mm diameter limb.This graft oversizing within the distal limb is likely the cause of graft infolding, overall luminal narrowing at this level and eventual stenosis of the flow channel due to focal thrombus formation.The iliac leg appears widely patent proximal and distal to this segment at the limb junction.Of note, though the 20 mm zsle leg may be slightly oversized for the native common iliac artery based on preoperative measurements, the next graft size down (16 mm) would be marginally undersized.If the implanted zsle leg was positioned distally all the way to the iliac bifurcation (as measurements suggested on the preoperative planning document), the flared segment would not be overlapping within the ipsilateral limb.Therefore, the preoperative planning/sizing for the iliac leg is probably appropriate, but the leg is just positioned too high.The imaging reviewer states the stenosis is due to focal thrombus formation and suggests graft infolding due to oversizing and the placement of the device contributed to the stenosis.Per the instructions for use (ifu), strict adherence to the zenith spiral-z aaa iliac leg ifu sizing guide is strongly recommended when selecting the appropriate device size.Appropriate device oversizing has been incorporated into the ifu sizing guide.Sizing outside of this range can result in endoleak, fracture, migration, device infolding or compression.Ifu also states, excessive overlap 10mm above the main body bifurcation may increase the risk of limb thrombosis.The device history record was reviewed and no non-conformances were noted.Thrombosis can occur for a variety of reasons, such as genetic predisposition, iliac tortuosity, external compression, stenosis, improper overlap, narrow inner iliac lumen, vessel damage, and rough surfaces.Tortuosity, compression, and pulsation can create high shear forces within the leg that stimulate thrombus growth.Where a small thrombus has formed, the clot can enlarge because the blood flow slows around the clot, allowing clot-forming elements to be deposited.Pulsation and a small inner lumen can occur through graft oversizing or undersizing.The image review confirmed over 50% stenosis of the mid right zsle leg related to thrombus formation.This thrombus formation was likely caused by the narrowing of the graft lumen diameter from 11mm to 7-8mm at this region.The right iliac leg was placed with 53 mm overlap in the ipsilateral limb with the distal leg sealing in the right common iliac artery 13mm above the iliac bifurcation.This resulted in 15mm of overlap between the flared zsle stent segment within the 11 mm diameter ipsilateral limb.This graft oversizing within the main body distal limb is likely the cause of graft infolding, overall luminal narrowing at this level and eventual stenosis of the flow channel due to focal thrombus formation.The planning and sizing sheet completed prior to the procedure states, "with the exception of the straight zsle-13-56-zt, it is not advisable to use 56mm lengths on the ipsilateral side due to device tapering that would occur within the main body." the sizing sheet indicated that a zsle-20-74 device was planned for the procedure but a 56mm graft was used instead.Additional information provided clarified that "when measured with the pig tail catheter during the procedure, it was felt that the 74 length would be too long and require more than maximum overlap.Although not recommend on the planning and sizing sheet, it was felt it was safer to use the 56 length than have more than maximum overlap.In hindsight a 84 length body would have been the best option to ensure a longer ipsilateral leg was used." it was also reported that the true length available was actually longer than anticipated possibly because of the vessel concertinaing with the stiff wire, the wire taking the racing line instead of the centerline, or simply because the correct angle was not used for imaging.The image reviewer also noted that the reconstructed images provided show mild tortuosity of the right iliac system and moderate to severe tortuosity of the left iliac system.Iliac tortuosity can create high shear forces within the leg that increase the risk of thrombus formation.Iliac tortuosity could have also contributed to the difficulties sizing and placing the ipsilateral zsle-20-56-zt.The cause of the stenosis within the right main body limb and zsle graft was most likely a result of the graft lumen narrowing and thrombus formation within this section because of the 15mm of overlap between the flared zsle stent segment within the distal main body ipsilateral limb.The compression of the flared zsle segment to 7-8mm resulted in graft infolding, fabric redundancy, flow disruption and greater shear forces through the narrowed lumen that increased the risk of thrombus formation.Iliac tortuosity as well as the ipsilateral zsle overlap above the main body bifurcation also increased the risk of thrombus formation through the graft.An additional cause is likely related to not following the instructions for use.Improper placement of the ipsilateral zsle-20-56 graft along with using the shorter than planned zsle device resulted in graft lumen narrowing and thrombus formation that occluded the graft.Measures have been initiated to address the failure modes of leg extension stent graft kinks and occlusions.Monitoring will continue to be performed for similar complaints.The appropriate cook personnel have been notified of this event.This report is required by the fda under 21 cfr part 803 and is based on unconfirmed information submitted by others.Neither the submission of this report nor any statement contained herein is intended to be an admission that any cook device is defective or malfunctioned, that a death or serious injury occurred, nor that any cook device caused, contributed to, or is likely to cause or contribute to a death or serious injury if a malfunction occurred.Blank fields on this form indicate the information is unknown, unchanged, or unavailable.Additional information was received on 24may2018.Concomitant medical products: correction ¿ the device was not returned.Imaging was received on 14mar2018.The actual complaint device was not returned.Without the complaint device, a physical investigation was not able to be completed.A documentation based investigation was performed.A review of provided imaging, the device planning and sizing worksheet, device history record, instructions for use, manufacturing instructions and quality control data was conducted.A preoperative case planning document and a 2-month postoperative computerized tomography (ct) scan study were provided.The preoperative case planning and sizing document was reviewed.The reconstructed images attached to the document show mild tortuosity of the right iliac system and moderate to severe tortuosity of the left iliac system.The 2-month postoperative ct study, dated 1/24/18, was reviewed.An aortic endograft (zalb 24 x 98 mm) is placed for repair of an infrarenal abdominal aortic aneurysm (aaa).The proximal graft is just below the lower left renal artery.The main body device appears widely patent and measures 19.5 mm in diameter, proximally.There may be some contrast outside the endograft, tracking from anterior to lateral within the sac.A patent inferior mesenteric artery and patent lumbar artery are adjacent to this level.Non-contrast images would be needed to compare to determine if this is a type 2 endoleak or artifact within the aaa sac.There is focal thrombus formation and a >50% stenosis in the mid zsle leg at the junction of the distal ipsilateral limb.The zsle leg proximally and distally appears widely patent.There is no kinking or angulation noted in the area of stenosis.The left iliac leg (zsle 16 x 56 mm) has 28 mm overlap within the contralateral limb and seals in the distal left common iliac artery with no distal endoleak.The iliac leg appears widely patent and measures 13.1 x 13.4 mm in diameter, distally.Both iliac legs are closely aligned proximally within the main body device.Impressions of the imaging reviewer: an infrarenal aaa is repaired with a zalb 24 x 98 mm main body device, a zsle 20 x 56 mm ipsilateral iliac leg on the right, and a zsle 16 x 55 mm contralateral iliac leg on the left.There may be a type 2 endoleak related to patent inferior mesenteric artery (ima) and lumbar arteries.There is >50% stenosis of the mid right zsle leg related to thrombus formation, focally, at the junction of the distal ipsilateral limb.There is no angulation or kinking noted at this level.The 20 mm zsle leg is placed 53 mm above the distal ipsilateral limb, causing a 15 mm length of the flared segment to overlap within the 11 mm diameter limb.This graft oversizing within the distal limb is likely the cause of graft infolding, overall luminal narrowing at this level and eventual stenosis of the flow channel due to focal thrombus formation.The iliac leg appears widely patent proximal and distal to this segment at the limb junction.Of note, though the 20 mm zsle leg may be slightly oversized for the native common iliac artery based on preoperative measurements, the next graft size down (16 mm) would be marginally undersized.If the implanted zsle leg was positioned distally all the way to the iliac bifurcation (as measurements suggested on the preoperative planning document), the flared segment would not be overlapping within the ipsilateral limb.Therefore, the preoperative planning/sizing for the iliac leg is probably appropriate, but the leg is just positioned too high.The imaging reviewer states the stenosis is due to focal thrombus formation and suggests graft infolding due to oversizing and the placement of the device contributed to the stenosis.Per the instructions for use (ifu), strict adherence to the zenith spiral-z aaa iliac leg ifu sizing guide is strongly recommended when selecting the appropriate device size.Appropriate device oversizing has been incorporated into the ifu sizing guide.Sizing outside of this range can result in endoleak, fracture, migration, device infolding or compression.Ifu also states, excessive overlap 10mm above the main body bifurcation may increase the risk of limb thrombosis.The device history record was reviewed and no non-conformances were noted.Thrombosis can occur for a variety of reasons, such as genetic predisposition, iliac tortuosity, external compression, stenosis, improper overlap, narrow inner iliac lumen, vessel damage, and rough surfaces.Tortuosity, compression, and pulsation can create high shear forces within the leg that stimulate thrombus growth.Where a small thrombus has formed, the clot can enlarge because the blood flow slows around the clot, allowing clot-forming elements to be deposited.Pulsation and a small inner lumen can occur through graft oversizing or undersizing.The image review confirmed over 50% stenosis of the mid right zsle leg related to thrombus formation.This thrombus formation was likely caused by the narrowing of the graft lumen diameter from 11mm to 7-8mm at this region.The right iliac leg was placed with 53 mm overlap in the ipsilateral limb with the distal leg sealing in the right common iliac artery 13mm above the iliac bifurcation.This resulted in 15mm of overlap between the flared zsle stent segment within the 11 mm diameter ipsilateral limb.This graft oversizing within the main body distal limb is likely the cause of graft infolding, overall luminal narrowing at this level and eventual stenosis of the flow channel due to focal thrombus formation.The planning and sizing sheet completed prior to the procedure states, "with the exception of the straight zsle-13-56-zt, it is not advisable to use 56mm lengths on the ipsilateral side due to device tapering that would occur within the main body." the sizing sheet indicated that a zsle-20-74 device was planned for the procedure but a 56mm graft was used instead.Additional information provided clarified that "when measured with the pig tail catheter during the procedure, it was felt that the 74 length would be too long and require more than maximum overlap.Although not recommend on the planning and sizing sheet, it was felt it was safer to use the 56 length than have more than maximum overlap.In hindsight a 84 length body would have been the best option to ensure a longer ipsilateral leg was used." it was also reported that the true length available was actually longer than anticipated possibly because of the vessel concertinaing with the stiff wire, the wire taking the racing line instead of the centerline, or simply because the correct angle was not used for imaging.The image reviewer also noted that the reconstructed images provided show mild tortuosity of the right iliac system and moderate to severe tortuosity of the left iliac system.Iliac tortuosity can create high shear forces within the leg that increase the risk of thrombus formation.Iliac tortuosity could have also contributed to the difficulties sizing and placing the ipsilateral zsle-20-56-zt.The cause of the stenosis within the right main body limb and zsle graft was most likely a result of the graft lumen narrowing and thrombus formation within this section because of the 15mm of overlap between the flared zsle stent segment within the distal main body ipsilateral limb.The compression of the flared zsle segment to 7-8mm resulted in graft infolding, fabric redundancy, flow disruption and greater shear forces through the narrowed lumen that increased the risk of thrombus formation.Iliac tortuosity as well as the ipsilateral zsle overlap above the main body bifurcation also increased the risk of thrombus formation through the graft.An additional cause is likely related to not following the instructions for use.Improper placement of the ipsilateral zsle-20-56 graft along with using the shorter than planned zsle device resulted in graft lumen narrowing and thrombus formation that occluded the graft.Measures have been initiated to address the failure modes of leg extension stent graft kinks and occlusions.Monitoring will continue to be performed for similar complaints.The appropriate cook personnel have been notified of this event.This report is required by the fda under 21 cfr part 803 and is based on unconfirmed information submitted by others.Neither the submission of this report nor any statement contained herein is intended to be an admission that any cook device is defective or malfunctioned, that a death or serious injury occurred, nor that any cook device caused, contributed to, or is likely to cause or contribute to a death or serious injury if a malfunction occurred.
Event or Problem Description
A zsle-20-74-zt was planned to be implanted as the ipsilateral leg on the planning and sizing sheet.During the procedure, when measured with the pig tail catheter, it was felt the 74 length would be too long and would require more than maximum overlap.It was not clear whether this was due to the vessel concertinaing with the stiff wire, the wire taking the racing line as opposed to the centerline, or simply because we weren't in the correct angle for appreciating the true length available.Although not recommend on the planning and sizing sheet, it was felt it was safer to use the 56 length than have more than maximum overlap.In hindsight a 84 length body would have been the best option to ensure a longer ipsilateral leg was used.

• Brand Name: ZENITH FLEX WITH SPIRAL-Z TECHNOLOGY AAA ENDOVASCULAR GRAFT ILIAC LEG
• Common Device Name: MIH SYSTEM, ENDOVASCULAR GRAFT, AORTIC ANEURYSM TREATMENT
• Manufacturer (Section D): COOK INC; 750 daniels way; bloomington IN 47404
• MDR Report Key: 7307411
• Report Number: 1820334-2018-00418
• Device Sequence Number: 1236990
• Product Code: MIH
• UDI-Device Identifier: 10827002552415
• UDI-Public: (01)10827002552415(17)200615(10)7968607
• Combination Product (Y/N): N
• PMA/510(K) Number: P020018
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2017
• Reporter Type: Manufacturer
• Report Source: company representative,foreig
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 05/30/2018

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?: No
• Operator of Device: Health Professional
• Device Model Number: G55241
• Device Catalogue Number: ZSLE-20-56-ZT
• Was Device Available for Evaluation?: No
• Initial Date Received by Manufacturer: 02/14/2018
• Supplement Date Received by Manufacturer: 03/28/2018; 05/24/2018
• Initial Report FDA Received Date: 03/01/2018
• Supplement Report FDA Received Date: 04/30/2018; 05/30/2018
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Required Intervention
• Patient Age: 85 YR