Geometric Remodeling of the Perirenal Aortic Neck at and Adjacent to the Double Sealing Ring of the Anaconda Stent-Graft After Endovascular Aneurysm Repair

Renal and Visceral Artery Configuration During the First Year of Follow-Up After Fenestrated Aortic Aneurysm Repair Using the Anaconda Stent-graft: A Prospective Longitudinal Multicenter Study With ECG-Gated CTA Scans

OBJECTIVE

The performance of fenestrated endovascular aortic aneurysm repair (FEVAR) may be compromised by complications related to the dynamic vascular environment. The aim of this study was to analyze the behavior of FEVAR bridging stent configurations during the cardiac cycle and during follow-up to improve our understanding on treatment durability.

DESIGN

Twenty-one patients presenting with complex abdominal aortic aneurysms (AAAs; 9 juxtarenal/6 pararenal/3 paravisceral/1 thoracoabdominal aortic aneurysm type IV), treated with a fenestrated Anaconda (Terumo Aortic, Inchinnan, Scotland, UK) with Advanta V12 bridging stents (Getinge, Merrimack, NH, USA), were prospectively enrolled in a multicenter observational cohort study and underwent electrocardiogram (ECG)-gated computed tomographic angiography (CTA) preoperatively, at discharge, 7-week, and 12-month follow-ups.

METHODS

Fenestrated endovascular aortic aneurysm repair stability was assessed considering the following variables: branch angle as the angle between the aorta and the target artery, end-stent angle as the angle between the end of the bridging stent and the native artery downstream from it, curvature and tortuosity index (TI) to describe the bending of the target artery. Body-bridging stent stability was assessed considering bridging stent flare lengths, the distances between the proximal sealing stent-ring and fenestrations and the distance between the fenestration and first apposition in the target artery.

RESULTS

Renal branch angles significantly increased after FEVAR toward a perpendicular position (right renal artery from median 60.9°, inter quartile range [IQR]=44.2-84.9° preoperatively to 94.4°, IQR=72.6-99.8°, p=0.001 at 12-month follow-up; left renal artery [LRA], from 63.7°, IQR=55.0-73.0° to 94.3°, IQR=68.2-105.6°, p<0.001), while visceral branch angles did not. The mean dynamic curvature only decreased for the LRA from preoperative (3.0, IQR=2.2-3.8 m-1) to 12-month follow-up (1.9, IQR=1.4-2.6 m-1, p=0.027). The remaining investigated variables did not seem to show any changes over time in this cohort.

CONCLUSIONS

Fenestrated endovascular aortic aneurysm repair for complex AAAs using the Anaconda fenestrated stent-graft and balloon-expandable Advanta V12 bridging stents demonstrated stable configurations up to 12-month follow-up, except for increasing renal branch angles toward perpendicular orientation to the aorta, yet without apparent clinical consequences in this cohort.

CLINICAL IMPACT

This study provides detailed information on the cardiac-pulsatility-induced (dynamic) and longitudinal geometry deformations of the target arteries and bridging stents after fenestrated endovascular aortic aneurysm repair (FEVAR) up to 12-month follow-up. The configuration demonstrated limited dynamic and longitudinal deformations in terms of branch angle, end-stent angle, curvature, and tortuosity index (TI), except for the increasing renal branch angles that go toward a perpendicular orientation to the aorta. Overall, the results suggest that the investigated FEVAR configurations are stable and durable, though careful consideration of increasing renal branch angles and significant geometry alterations is advised.

Differences in Cardiac-Pulsatility-Induced Displacement and Geometry Changes between the Cook ZBIS and Gore IBE: Postoperative Comparison Using ECG-Gated CTA Scans

To what extent the stentgraft design of iliac branch devices (IBDs) relates to dynamic deformation is currently unknown. Therefore, this study aimed to quantify and compare displacement and geometry changes during the cardiac cycle of two common IBDs. This paper presents a two-center trial with patients treated with a Zenith bifurcated iliac side (ZBIS) or Gore iliac branch endoprosthesis (IBE). All patients underwent a retrospective electrocardiogram (ECG)-gated computed tomographic angiography (CTA) during follow-up. Cardiac-pulsatility-induced displacement was quantified for the following locations: (neo) bifurcation of the aorta, IBD flow divider, distal markers of the internal iliac artery (IIA) component and first IIA bifurcation. Geometrical parameters (length, tortuosity index, curvature and torsion) were quantified over centerlines. Displacement was more pronounced for the IBE than the ZBIS, e.g., craniocaudal displacement of 0.91 mm (0.91-1.13 mm) vs. 0.57 mm (0.40-0.75 mm, p = 0.004), respectively. The IBDs demonstrated similar geometrical parameters in the neo-common iliac artery and distal IIA, except for the larger dynamic curvature and torsion of the distal IIA in IBEs. The IBEs showed more dynamic length and curvature change compared to the ZBIS in the stented IIA. The IIA trajectory showed more pronounced deformation during the cardiac cycle after placement of an IBE than a ZBIS, suggesting the IBE is more conformable than the ZBIS.

Current assessment and management of endoleaks after advanced EVAR: new devices, new endoleaks?

INTRODUCTION

In recent years there has been an increasing application of advanced EVAR techniques to tackle complex clinical and anatomical scenarios. In a bid to overcome the limitations of the traditional stent-grafts, newer EVAR endografts and techniques have been developed and introduced into clinical practice, permitting endovascular management of difficult infrarenal, juxta-renal and thoracoabdominal aneurysms for which previously there was no endovascular solution. As a consequence, we are now confronted with unique patterns of endoleak requiring customized clinical-radiological assessment and treatment. Despite the increasing body of evidence regarding new EVAR techniques and related endoleaks, current guidelines do not specifically address these issues.

OBJECTIVES

Our review aims to assess risk factors, development, and management strategies of these endoleaks, in the most recent infrarenal EVAR devices and in more complex fenestrated EVAR (FEVAR) and Chimney EVAR (Ch-EVAR).

EXPERT OPINION

Most new devices have demonstrated types of endoleaks that need specific imaging and treatment, as in EVAS, FEVAR, and ChEVAR. Knowledge of specific stent-graft characteristics and the nature of endoleaks associated with the various procedures facilitates the application of relevant useful imaging. In addition, it should aid development of a customized and practically relevant approach to patient management during intervention and follow-up.