Mid-term Results of the Anaconda Fenestrated Stent-Graft Proximal Sealing System in the Exclusion of Complex Abdominal Aortic Aneurysms

Abstract

Context:

Mid-term data on the Anaconda fenestrated stent-graft remain scarce in the literature.

Objective:

The aim of this study was to evaluate the efficacy and durability of its Z-stent-free proximal sealing system.

Methods:

All consecutive patients treated between January 2018 and May 2023 with the Anaconda Fenestrated stent-graft (Vascutek/Terumo, Scotland, UK) for complex abdominal aortic aneurysm (AAA) were retrospectively included in this monocentric study. The primary outcome was the occurrence of type Ia endoleak (EL). The secondary outcome was the evolution of the proximal sealing zone (PSZ), defined as proximal neck dilatation (PND) ≥3 mm, stent-graft migration (>10 mm), or the need for PSZ-related reintervention. Effective oversizing (OS) was calculated from the nominal stent-graft diameter and the mean aortic diameter at the PNR level on postoperative computed angiography (CT) angiography.

Results:

A total of 111 patients were included (mean age 72±7.6 years, 86% male) with 69 juxta renal aneurysms (62.2%), 23 para-renal aneurysms (20.7%), and 19 proximal EL after EVAR (17.1%). The mean follow-up was 28.1±16.2 months. No primary type Ia EL was observed at discharge. During follow-up, 1 patient (<1%) developed a secondary type Ia EL, which was successfully managed with the placement of an aortic cuff. The PND was observed in 40 patients (36%), while significant stent-graft migration was observed in 1 patient (0.9%) without any impact on proximal sealing or bridging-stents. Effective OS was the only independent predictor of PND in the multivariable analysis (odds ratio [OR]=1.193; 95% confidence interval [CI]= 1.104-1.288; p<0.001). Seven patients (6.3%) underwent prophylactic PSZ-related reintervention, at a mean interval of 26.4±16.9 months following the index procedure, to prevent the occurrence of a type Ia EL.

Conclusion:

The proximal sealing system of the Anaconda fenestrated stent-graft’s demonstrates encouraging mid-term performance, with a low incidence of type Ia EL observed over more than 2 years of follow-up. The PND related to stent-graft OS is common but generally stabilizes after the first year. Beyond this point, any progression should be attributed to the underlying aortic disease. In such cases, proximal extension of the sealing zone can be performed with satisfactory outcomes.

Clinical Impact

This study provides the first dedicated mid-term evaluation of the proximal sealing system of the Anaconda® fenestrated stent-graft in complex abdominal aortic aneurysms. When implanted in a healthy supraceliac landing zone with adequate effective oversizing, the device offers durable proximal sealing with a low incidence of type Ia endoleak. These findings support confident use of the Anaconda® platform in challenging anatomies, while emphasizing the importance of careful deployment to avoid use of the repositioning system and the associated risk of ring tilting. The study also highlights that early proximal neck dilatation is common but usually stabilizes, justifying tailored surveillance and allowing prophylactic proximal extension when necessary.