EVAR in patients with large diameter necks is associated with an increased risk of neck-related adverse events in midterm follow-up. This may influence the clinical decision regarding choice of repair and toward a more intensive surveillance following EVAR in these patients in the long term.

WHAT THIS PAPER ADDS Failure after EVAR is most often associated with loss of seal and consequent re-pressurisation of the aneurysm sac. This study explores the evolution of the iliac seal zones after implantation, showing that progressive dilatation and retraction are very common occurrences, which in turn have clinical consequences. Careful attention to planning to take full advantage of the potential iliac seal, avoidance of "bell-bottom" limbs whenever possible, and attention to signs of excessive dilatation and/or retraction over the course of follow-up are practical recommendations derived from the conclusions of this study that may improve outcomes.Objective: To evaluate the dynamics of the iliac attachment zone after EVAR, and the association with clinical events. Methods: A tertiary institution's prospective EVAR database was searched to identify common iliac arteries at risk. Internally validated measurements were made, using centre lumen line reconstructions. Iliac dilatation and endograft limb retraction were the main endpoints. Associations between dilatation, retraction, oversizing, and distal seal length were investigated. Association with clinical events (sealing or occlusion) was also explored. Results: Of 452 primary EVAR patients treated from 2004 to 2012, 341 were included (mean age 72 years, 12% female, 597 common iliac arteries). Median follow-up was 4.7 years. At 30 days, the mean iliac diameter increased from 14 mm to 15 mm (p < .001). Over follow-up, it increased to 18 mm (p < .001). Iliac dilatation !20% occurred in 295 cases (49.4%) and exceeded the implanted endograft diameter in 170 (28.7%). Limb retraction !5 mm was identified in 54 patients (9.1%) and was associated with iliac seal complications (p < 0.001). Iliac endograft extension diameter !24 mm (OR 3.3, 95% CI 1.7e6.4) and iliac artery dilatation beyond the endograft (OR 2.1, 95% CI 1.2e3.8) were independent risk factors. Overall, there were 34 (5.7%) iliac seal complications. Retraction of the iliac endograft (OR 1.17 per mm, 95% CI 1.10e1.24) and baseline AAA diameter (1.04 per mm, 95% CI 1.01e1.07) were independent risk factors for seal related complications. Greater initial post-operative iliac seal length was protective (OR 0.94 per mm, 95% CI 0.90e0.97). Conclusions: Iliac dilatation and endograft retraction are common findings during follow-up, potentially leading to adverse clinical events. Optimisation of the iliac seal zone providing a long distal seal length and added attention to patients with large aneurysms or receiving !24 mm diameter iliac extensions are recommended. Also, long-term surveillance including CTA is advised to reveal and correct loss of seal at the iliac attachments before adverse clinical events occur. Ó

Despite satisfactory results early and in the midterm, a higher rate of EL1A was identified among patients with severely angulated necks in the long term. However, mortality was not affected by this difference. These findings suggest that EVAR should be used judiciously in patients with extreme angulation of the proximal neck and highlight the need for close follow-up of EVAR, especially in the long term and in patients treated outside instructions for use.

WHAT THIS PAPER ADDS Aortic neck dilatation occurs after endovascular aneurysm repair (EVAR) with self expanding stent grafts but may progress, ultimately exceeding the implanted endograft's diameter, placing patients at risk of abdominal aortic aneurysm rupture. This study suggests that aortic neck dilatation after EVAR is driven by endograft oversizing and radial force. Despite being greater during the first post-operative year, it decreases once the nominal endograft size is reached in most cases. Importantly, baseline aortic neck diameter and endograft characteristics were associated with an increased risk of neck dilatation beyond the nominal graft diameter. The importance of suprarenal stents remains uncertain as the studied suprarenal fixation endografts have greater radial force than their infrarenal counterparts. Additionally, patient selection differences may also have contributed to the reported findings. For patients at risk of excessive neck dilatation and with a long life expectancy, alternative repairs may be preferable for a durable result.Objective: Aortic neck dilatation (AND) occurs after endovascular aneurysm repair (EVAR) with self expanding stent grafts (SESs). Whether it continues, ultimately exceeding the endograft diameter leading to abdominal aortic aneurysm (AAA) rupture, remains uncertain. Dynamics, risk factors, and clinical relevance of AND were investigated after EVAR with standard SESs. Methods: All intact EVAR patients treated from 2000 to 2015 at a tertiary institution were included. Demographic, anatomical, and device related characteristics were investigated as risk factors for AND. Outer to outer diameters were measured at a single standardised aortic level on reconstructed computed tomography (CT) images. Results: A total of 460 patients were included (median follow up 5.2 years, interquartile range [IQR] 3.0, 7.7 years; CT imaging follow up 3.3 years, IQR 1.3, 5.4). Baseline neck diameter was 24 mm (IQR 22, 26) and increased 11.1% (IQR 1.5%, 21.9%) at last CT imaging. Endograft oversizing was 20.0% (IQR 13.6, 28.0). AND was greater during the first year (5.2% [IQR 0, 11.7]) decreasing subsequently (two to four years to 1.4%/year [IQR 0.0, 4.5%], p .001) and was associated with suprarenal fixation endografts (t value ¼ 7.9, p < .001) and oversizing (t value ¼ 4.4, p < .001). AND exceeding the endograft was 3.5% (95% CI 2.2% e 4.8%) and 14.4% (95% CI 11.0% e 17.8%) at five and eight years, respectively. Excessive AND was associated with baseline neck diameter (OR 1.2/mm, 95% CI 1.05 e 1.41) while the Excluder endograft had a protective effect (OR 0.15, 95% CI 0.04 e 0.58). Excessive AND was associated with type 1A endoleak (HR 3.3, 95% CI 1.1 e 9.7) and endograft migration > 5 mm (HR 3.1, 95% CI 1.4 e 6.9). Conclusion: AND after EVAR with SES is associated with endograft oversizing and radial force but decelerates after the first post-operative year. Baseline aortic neck diameter and suprarenal stent bearing endografts were associated with an increased risk of AND beyond nomin...

Mid-term outcomes following EVAR with the Endurant Stent Graft were not influenced by severe proximal neck angulation in our population. Despite the conformability of the device, moderate aortic neck remodeling was identified in the group of patients with angulated neck anatomy on the first computed tomography scan after implantation with no important further remodeling afterwards. No device integrity failures were encountered.

Objective: Many endografts are currently available for standard endovascular repair of infrarenal abdominal aortic aneurysms. Comparison of long-term outcomes between devices might aid in this decision process, but comparative data are scarce. The purpose of this study was to report long-term clinical outcomes of two commercially available endoprosthesis, the Endurant (Medtronic Vascular, Inc, Minneapolis, Minn) and the Excluder (W. L. Gore & Associates, Flagstaff, Ariz) stent grafts.Methods: Patients undergoing standard endovascular repair from July 2004 to December 2011 in a single institution with the Endurant or the Low-Porosity Excluder endografts were eligible. Only patients treated for intact degenerative abdominal infrarenal aneurysms were included. All measurements were performed on center-lumen line reconstructions obtained on dedicated software. The primary end point was primary clinical success, defined as clinical success without the need for an additional or secondary surgical or endovascular procedure. Neck-related events (a composite of type IA endoleak, neck-related secondary intervention, or migration of >5 mm), neck morphology changes, renal function, and overall survival were secondary end points.Results: The study included 277 patients (156 Endurants; 121 Excluders). The median follow-up was 5.8 years (range, 0.1-12.4 years) and did not differ between groups (P ¼ .18). Patients treated with the Endurant stent graft had wider (neck diameter of >28 mm, 27.3% vs 1.7% [P < .001]; neck diameter of 27 mm, [interquartile range (IQR), 24-29 mm] for Endurant and 24 mm [IQR, 22-25 mm] for Excluder; P < .001) and more angulated necks (b-angle of >60 , 26.7% vs 12.5%; P ¼ .004). Oversizing was greater in the Endurant group (16% [IQR, 12%-22%] vs 13% [IQR, 8%-17%], respectively; P < .001). Patients were treated outside device instructions for use regarding proximal neck: 16.7% in the Endurant and 17.3% in the Excluder group (P ¼ .720). The 7-year primary clinical success was 54.7% for the Endurant and 58.1% for the Excluder groups (P ¼ .53). Freedom from neck-related events at 7 years was 76.7% for the Endurant and 78.8% for Excluder group (P ¼ .94). The Endurant stent graft (hazard ratio [HR], 2.7; 95% confidence interval [CI], 1.3-5.8; P ¼ .009) was an independent predictor of significant renal function decline. Neck dilatation was greater in Endurant-implanted patients (13% [95% CI, 2%-22%] vs 4% [95% CI, 0%-10%]; P < .001). Overall survival at 7 years was 61.4% in the Endurant and 50.3% (n ¼ 50; standard error, 0.047) in the Excluder group (P ¼ .39).Conclusions: This study reveals that durable and sustainable results can be obtained with either of these late generation devices. This finding suggests that careful planning and a tailored device selection taking into account the patient's anatomy are more relevant determinants than the graft model itself to obtain clinical success. The Endurant endoprosthesis seems to be associated with a higher rate of neck dilatation and faster decrease in the estimate...

Long-term mortality and complications after rEVAR are associated with aneurysm anatomy. The role of adjunct endovascular techniques and the outcome of open repair in cases with challenging anatomy warrant further study.

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