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	G55246
Medical Device Problem Code	Partial Blockage (1065)
Health Effect - Clinical Codes	Pain (1994); Claudication (2550)
Date of Event	06/22/2018
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
The (b)(6) male patient with an abdominal aortic aneurysm (aaa) underwent endovascular aneurysm repair (evar) on (b)(6) 2016.A zenith flex with spiral-z technology aaa endovascular graft iliac leg was implanted in the right limb.As reported, the patient has developed pain and claudication due to total right limb occlusion.No intervention has been undertaken or is currently planned.
Event or Problem Description
Additional information was received on (b)(6) 2018, confirming the date the patient presented with symptoms was on (b)(6) 2018.On (b)(6) 2018, it was also reported that the patient symptoms were caused by thrombus formation within the graft and this was likely observed using ultrasound.
Additional Manufacturer Narrative
The device was not available for evaluation.Without the complaint device, a physical investigation was not able to be completed.Imaging was provided.A document based investigation has been performed.A review of provided imaging, the device history record, instructions for use and quality control data was conducted.The device history record for complaint lot number 6517056 was reviewed and no non-conformities were noted.A preoperative computed tomography (ct) study and a 5-week postoperative ct study were provided for image review.A preoperative study dated (b)(6) 2016 showed an infrarenal abdominal aortic aneurysm (aaa) with maximum diameter of 55.9 x 44.4 mm.The proximal neck has parallel walls but dense calcification along the posterior and medial walls.The aortic diameter measures between 19.5 and 21 mm through the proximal neck.The right common iliac artery (cia) is dilated from the proximal to mid segment with a maximum diameter of 21.2 mm then reduces to 14.5 x 12.2 mm at the iliac bifurcation.This diameter change is seen within the distal 10 mm seal zone from the iliac bifurcation.There is dense calcification around 50% of the artery wall at the iliac bifurcation, causing a lumen diameter reduction to 11.2 x 12.2 mm.The outflow right external iliac artery (eia) is widely patent with a minimum diameter of 9.5 mm and no evidence of occlusive disease.There is moderate to severe tortuosity of the mid eia but no calcification present.The left cia is widely patent with a diameter of 13.4 mm at the bifurcation and through the 10mm distal seal zone.There is dense focal calcification on one side of the artery wall at this level.There is focal dilation in the mid left cia, above the distal seal zone, to a diameter of 15.7 mm.The left eia is widely patent with occlusive disease or calcification and only mild to moderate tortuosity.A 5-week postoperative ct study dated on (b)(6) 2016 shows a 56 mm aaa is repaired with a zenith alpha abdominal main body device (likely 24 x 118 mm), a right zsle (24 x 74 mm) flared iliac leg, and a left zsle (likely 16 x 74 mm) iliac leg.The proximal graft begins 3.9 mm below the left renal artery (lra) and has 16 mm length of proximal seal.No endoleak is seen here.The maximum graft diameter at the mid body is 24 mm.The maximum aaa diameter is 53 x 45.7 mm.Very small, limited type 2 endoleaks may be seen adjacent to patent lumbar arteries.The right zsle leg (24 x 74 mm) has 53 mm overlap within the ipsilateral limb and extends to the distal right cia where it seals just above the iliac bifurcation.The zsle leg diameter measures 21 mm in the dilated segment of the mid cia, then reduces significantly to 12.5 mm in the seal zone (10 mm from the distal edge of the graft) and further reduces to a lumen diameter of 6.2 x 5.2 mm at the distal graft edge.There is dense calcification at the distal graft deflecting it away from the arterial wall and further reducing the graft diameter.No endoleak is seen extending beyond the distal graft edge.The left zsle leg (likely a 16 x 74 mm device) has 20 mm overlap within the contralateral limb and extends to the distal left cia where it seals adequately just above the bifurcation.The left iliac leg is widely patent with no kinks or endoleak around it.The outflow external iliac arteries appear widely patent, bilaterally.The image reviewer concluded that the implanted zsle leg is sized for the 21mm segment of the artery.However, it is severely oversized for the distal segment of the seal zone where it lands.The leg diameter is further reduced due to severe calcification at the distal graft edge, causing it to deflect away from the artery wall.The resulting graft lumen diameter of the right zsle leg significantly narrows from 21 mm in the mid segment to 5.2 mm at the distal leg.This severe graft oversizing and lumen reduction, distally, is likely the cause of the (reported) subsequent graft occlusion.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 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.Thrombus formation could not be confirmed on the imaging provided.Significant lumen narrowing from 21mm to 5.2mm within the distal seal zone of the right zsle was confirmed.According to the instructions for use (ifu) sizing guide, the intended iliac vessel diameter for the 24mm zsle device is 19-20mm.The right cia had a maximum diameter of 21.2 mm then reduced to 14.5 x 12.2 mm at the iliac bifurcation based on preoperative study measurements.This diameter change was seen within the distal 10 mm seal zone from the iliac bifurcation.Based on maximal diameter within the seal zone, the device was appropriately sized according to ifu guidelines.The abrupt change in distal diameter caused the 24mm distal seal stent to be significantly oversized within the distal seal zone.There was dense calcification at the iliac bifurcation that reduced the lumen diameter to 11.2 x 12.2 mm.The distal edge of the right zsle leg was placed within this region.This further reduced leg diameter at the distal graft edge, causing it to deflect away from the artery wall.According to the ifu, vessels that are significantly calcified, occlusive, tortuous or thrombus-lined may preclude placement of the endovascular graft and/or may increase the risk of embolization.Calcification and narrowing within the distal seal zone reduced the lumen diameter from 21mm to 5.2mm.The distal seal zone lumen diameter was narrowed to a minimum of 5.2mm.The ifu states that follow-up imaging should be carefully reviewed for narrowing within the graft leg.Patients with a graft leg lumen of less than approximately 5 mm id may be at increased risk of a thromboembolic event (e.G., graft limb occlusion).Compression of the 24mm zsle sealing stent to 5.2mm would have created high shear forces through the graft, increasing the risk of thrombus formation.This complaint is confirmed based on customer testimony.Significant lumen narrowing of the zsle distal seal stent was confirmed from the imaging provided.There is no evidence to suggest that the device was manufactured out of specifications.The zsle-24-74-zt (lot: 6517056) is a one-device lot, therefore there is no nonconforming product in house or in the field.The thrombus occlusion of the right zsle-24-74-zt was a result of calcification and lumen narrowing within the distal seal zone.Since the 24mm zsle was sized for the 21mm seal zone diameter, the sealing stent was significantly oversized when the seal zone narrowed to 12.2mm.Further lumen narrowing to 11.2 mm was caused by dense calcification within the seal zone.This further reduction in lumen diameter at the zsle distal graft edge caused the seal stent to deflect away from the artery wall, narrowing to 5.2mm.This narrowing increased the risk of thrombus formation after the 5-week postoperative ct provided.The conclusion is the cause cannot be traced to the device ¿ the adverse event is related to the patient condition.The significant calcification and narrowing within the distal seal zone was the most likely cause for the thrombus formation within the graft.A quality engineer risk assessment was conducted to assess the risk of this failure mode and concluded a change is not required, thus no risk reduction activities are required at this time.The appropriate internal personnel have been notified and we will continue to monitor for similar complaints.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.

• 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: 7674382
• Report Number: 1820334-2018-01971
• Device Sequence Number: 16496287
• Product Code: MIH
• UDI-Device Identifier: 10827002552460
• UDI-Public: (01)10827002552460(17)190121(10)6517056
• Combination Product (Y/N): N
• Initial Reporter Country: CA
• PMA/510(K) Number: P020018
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2016
• Reporter Type: Manufacturer
• Report Source: company representative,foreig
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 11/13/2018

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Expiration Date: 01/21/2019
• Device Model Number: G55246
• Device Catalogue Number: ZSLE-24-74-ZT
• Device Lot Number: 6517056
• Was Device Available for Evaluation?: No
• Initial Date Received by Manufacturer: 06/22/2018
• Supplement Date Received by Manufacturer: 10/10/2018
• Initial Report FDA Received Date: 07/10/2018
• Supplement Report FDA Received Date: 11/13/2018
• 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: Disability
• Patient Age: 85 YR