Long-term results of endovascular intervention with unibody bifurcation endograft for elective abdominal aortic aneurysm management

Abstract

Unibody bifurcated endografts have the advantage of reducing the operative time, avoiding migration and iliac limb dislocation in patient with abdominal aortic aneurysm (AAA). We report our longterm experience in patients who underwent endovascular aortic repair (EVAR) due to infrarenal AAA with Endologix AFX® endograft system. Between January 2013-December 2018, 68 patients with infrarenal AAA had EVAR procedure with Endologix AFX® endograft system. Mean follow-up was 40.4 ± 19.5 months, and all patients had computed tomography periodically, with colored Doppler ultrasonography (CDUS) every six months. Mean age was 68.5 ± 7.1 years and, 63 (92.6%) patients were male. Early mortality, renal complications, stent-graft migration and cardiac complications were not seen in early post-operative period. There was no early mortality in the group and no conversion to open repair. In long-term follow-up 12 patients (17.6%) had endoleak (5 with type II, 7 with type III). Overall survival estimated by Kaplan-Meier analysis was 94.1% at 1 year, 85.2% at 2 years, 74.1% at 3 years and 54.0% at 5 years. Freedom from second intervention and conversion was 98.4% at 1 year, 95.3% at 2 years, 93.3% at 3 years and 87.4% at 5 years. Endologix AFX® endograft provides a fast, safe and effective endograft for the early period, therefore it seems more suitable for elderly and comorbid patients. This endograft has low reintervention rates however according to our results, aneurysms larger than 6 cm may have more sideway displacement possibility and by this way type III endoleak. Proper patient selection and sufficient overlap are the key issues. Close monitoring is mandatory at the follow-up period.

Delayed migration due to shortening of the lower part of AFX endograft's main body in angled fusiform abdominal aortic aneurysm

“…A large fusiform AAA (>60 or >65 mm) that provides space for migration could also play a vital role, as previously reported. 10 , 11 Saccular or locally dissected AAAs with no movement space showed no migration in our series and might be more suitable for AFX use.…”

“…Although the cause of adverse outcomes with the AFX is still unknown, two studies reported that large (>60 or >65 mm) AAAs tended to cause sideways displacement, producing type IIIa endoleaks. 10 , 11 …”

Midterm outcomes of AFX2 endografts used in combination with aortic cuffs

“…Due to these factors, the AFX2 is more prone to migration, sideways displacement, and subsequent type-IIIa endoleaks, as compared to other devices. 9,13 Although only four cases of type-III endoleaks were found in this study, the four cases of sideways displacement may present type-IIIa endoleaks in the future. We opine that the three-year follow-up period should be sufficiently short to assess the number of type-III endoleaks occurrences considering the cases of sideways displacement.…”

“…Another anatomical risk of migration is a large AAA diameter of more than 60 or 65 mm. 9,14 Two hypotheses have been reported: the deformation of the sideways displacement can occur within a sufficient AAA sac volume, and the billowing fabric of the aortic cuff provides a J o u r n a l P r e -p r o o f reverse windsock effect that increases distraction forces between the main body and aortic cuff.…”

“…6,7 The AFX was considered ideal for a saccular AAA, narrow aortic bifurcations, hostile (e.g., reverse tapered or bulging) necks, and cases with a short length from the lower renal artery to the aortic bifurcation. 7 However, this unibody endograft has shown high rates of type-III endoleaks, [8][9][10] and the U.S. Food and Drug Administration (FDA) issued a Class I voluntary recall of AFX systems J o u r n a l P r e -p r o o f in 2018. Nevertheless, there has been no clear evidence of flaws in studies using large cohorts and less bias.…”