Two Decades of Abdominal Aortic Endovascular Repair With the Anatomical FiXation at the Aortic Bifurcation in a Large Single-Center Experience

Abstract

Objective: The introduction of new endograft models improved long-term results of abdominal aortic aneurysm (AAA) endovascular repair (EVAR), but most of them maintained an old and unchanged design: a short body and long legs shifting up the flow divider. This study assessed the long-term results of EVAR with unimodular endoprosthesis fixed at the aorto-iliac bifurcation (Anatomical FiXation), in a large, unselected cohort.

Materials and methods: In a single-center, retrospective cohort study, 623 patients selectively treated between 1999 and 2016, were analyzed. Follow-up protocol included at least a computed tomography angiography within 3 months and a duplex ultrasound and clinical exam yearly. All enrolled patients were analyzed by 2020. The primary outcomes were technical success, clinical success, and survival. Secondary outcomes included survival-free from late-open-conversion (LOC), reintervention, and endoleaks.

Results: Median age was 74±11 years and the follow-up 93±54 months. The technical success was achieved in 99.4% and the 30-day clinical success was 98.4%. A 5-year clinical success of 97.7% was registered and at 10 years success was 96.7%. The overall survival at 1, 5, 10, and 15 years was 92.4%, 79.5%, 64.9%, and 45.5%, respectively. Six (0.98%) AAA-related death were registered, 3 caused by infection of the endograft and 3 for secondary rupture. LOCs were 9 (1.47%) and reintervention-free survival at 1, 5, 10, and 15 years were 88.4%, 78.0%, 76.2%, and 74.6%, respectively. Freedom from endoleaks was 88.8% at 1 year and 72.7% at 15 years. A total of 63 high-flow endoleaks were registered (43 type I, 7 type IIIa, 12 type IIIb, and 1 type Ib+IIIb). No migrations were recorded, and the graft limb thrombosis rate was 1.14%. From a multivariate analysis resulted that long-term clinical success appeared to be reduced in patients affected by diabetes [odds ratio (OR) 0.24; p=0.04] and in presence of calcified and thrombotic iliac accesses (OR 0.16; p=0.006).

Conclusion: EVAR with the Anatomical FiXation was confirmed to be safe, feasible, and effective to prevent AAA rupture in the long term as well. However, the overall survival remains afflicted by cardiovascular accident. The original concept of unibody bifurcated design allowed a very low rate of graft thrombosis and zeroed the risk of migration and related reintervention.

Keywords: abdominal aortic aneurysm; aneurysm; aneurysm neck; aneurysm sac; bifurcated stent-graft; endograft; endoleak; endovascular aneurysm repair; fixation; migration.