Short-term and Midterm Results of Fenestrated Anaconda Endograft in Patients with Previous Endovascular Aneurysm Repair

Can the Fenestrated Anaconda™ salvage failed competitor endografts? An international frame of reference

INTRODUCTION

An abdominal aortic aneurysm (AAA) is a life-threatening abnormal dilation of the abdominal aorta that can be repaired either endovascularly or with open surgery. However, endovascular aortic repair (EVAR) has become the main treatment modality for AAA due to its more optimal results. EVAR devices can either be standard, fenestrated, or branched, with fenestrated EVAR (FEVAR) seemingly achieving superior prospects. Although EVAR is associated with excellent outcomes, it still carries a risk of certain complications requiring reintervention or 'rescue'. Several commercial EVAR devices are available on the global market, nevertheless, the Fenestrated Anaconda developed by Terumo Aortic can be considered the superior device due to the wide range of endovascular solutions that it offers along with its unique custom-made approach, excellent results and its highly promising potential to be used as a 'rescue' device for failed competitor endografts.

MATERIALS AND METHODS

The current study represents a 9-year cross-sectional international analysis of a custom-made Fenestrated Anaconda™ device. For the statistical analysis, SPSS 28 for Windows and R were utilised. Pearson Chi-square analysis was used to assess differences in cumulative distribution frequencies between select variables. Statistical significance for all two-tailed tests was set at p < 0.05.

RESULTS

Out of 5058 EVARs performed using the Fenestrated Anaconda, 2987 (59%) were 'rescue' procedures for migrated Gore (n = 252) and Medtronic (n = 2735) devices. The Fenestrated Anaconda™ was indicated as the reintervention device either due to unsuitable/complex anatomy for the competitor (n = 2411) or based on surgeon preference (n = 576). Overall, the Fenestrated Anaconda was utilised to rescue 3466 (68.5%) failed previous EVARs using competitor devices. Yet, the primary endovascular solution offered by the Fenestrated Anaconda was FEVAR (91.3%), with 112 (2.2%) devices using custom-made iliac stents.

DISCUSSION

The use of the Fenestrated Anaconda endograft as a 'rescue' device to salvage failed competitor devices is well-established in the literature with excellent clinical outcomes achieved. The evidence in the literature also highlights the distinctive custom-made approach that the Fenestrated Anaconda offers which enables it to treat extremely complex aortic anatomy.

Endovascular solutions for abdominal aortic aneurysms: A comparative review of clinical outcomes with custom-made endografts

BACKGROUND

The introduction of endovascular aortic repair has revolutionised the treatment of abdominal aortic aneurysms, replacing open surgical repair for the majority of elective cases due to its optimal morbidity and mortality. Several endovascular aortic repair stent grafts exist commercially, one of which is the Fenestrated Anaconda™ by Terumo Aortic which benefits from a very innovative design, unique custom-made approach and highly favourable results.

AIMS

The main scope of this narrative review is to provide a comprehensive overview of endovascular aortic repair clinical outcomes using the Fenestrated Anaconda™ stent-graft and comparing these with its market competitor, Zenith. This review will also examine the evidence in the literature on the Anaconda™'s custom-made approach.

METHODS

A comprehensive literature was conducted on several search engines including PubMed, Google Scholar, Ovid, Scopus and Embase to collate the evidence in the literature on clinical outcomes achieved with the Fenestrated Anaconda™ and Zenith including, but not limited to, survival, technical success, target vessel patency, endoleak, reintervention and aneurysm sac regression.

RESULTS

The Fenestrated Anaconda™ is associated with excellent results, including highly favourable survival, technical and clinical success and target vessel patency rates, very low need for reintervention or conversion, and minimal incidence of complications such as endoleak and endograft migration. The Fenestrated Anaconda™ also drives significant sac regression and aortic remodelling. In addition, its unique custom-made approach enables it to treat highly complex aortic anatomy as well as to 'rescue' failed competitor grafts.

CONCLUSION

The Fenestrated Anaconda™ has proven that it is a very safe, highly applicable and extremely effective device used for complex aortic and/or iliac pathology based on its novel design and outstanding track record of clinical outcomes.

Incidence and predictive factors for endograft limb patency of the Fenestrated Anaconda™ endograft used for complex endovascular aneurysm repair

OBJECTIVE

To describe the incidence, risk factors and outcomes of treatment for limb occlusion in patients treated for complex (thoraco-)abdominal aortic aneurysms (AAA) with the Fenestrated Anaconda™.

METHODS

Between June 2010 and May 2018, 335 patients underwent elective fenestrated aortic aneurysm repair in 11 participating centers using the Fenestrated Anaconda™ with a median follow-up of 14.3 months (IQR 27.4). The primary outcome measure was freedom-from-limb-occlusion. Secondary outcome measures were freedom-from-limb-related-reintervention, secondary patency, and risk factors associated with limb occlusion.

RESULTS

Thirty (9.0%) patients presented with limb occlusion during follow-up with freedom-from-limb-occlusion of 98.5%, 91.2%, and 81.7% at 30-days, 1 and 5 years, respectively. In 87% of cases, no obvious cause for limb occlusion was documented. Primary occlusion occurred within 30-days in 36.7% and within 1 year in 80.0%. Twenty-three (6.9%) patients underwent an occlusion-related reintervention; seven (23.3%) patients were treated conservatively. Freedom-from-limb-occlusion-related-reintervention at 30-days, one and five years was 97.8%, 93.2% and 88.6%, respectively. Secondary patency was 91.3% after 1-month and 86.2% after 1 and 5 years, respectively. Female sex (OR 3.27 - 95% CI 1.28 to 8.34, P = .01) was a statistically significant predictor for limb occlusion. A higher percentage of thrombus in the aneurysm sac appeared to be protective for limb occlusion (0% compared to <25%: OR 0.22 - 95% CI 0.07 to 0.63, P = .01; 0% compared to 25-50%: OR 0.20 - 95% CI 0.07 to 0.57, P = .00 and 0% compared to >50%: OR 0.08 - 95% CI 0.02 to 0.38, P = .00), as did iliac angulation (OR 0.99 - 95% CI 0.98 to 1.00, P = .04).

CONCLUSION

Limb occlusion remains a significant impediment of endograft durability in patients treated with the Fenestrated Anaconda™, especially in female patients. Controversially, a high aneurysmal thrombus load and a high degree of iliac angulation appeared to be protective for limb occlusion, for which no obvious cause could be identified.

Late Type 1A Endoleaks: Associated Factors, Prognosis and Management Strategies

BACKGROUND

Unlike periprocedural Type 1A endoleaks, late appearing proximal endoleaks have been poorly described.

METHODS

We studied all elective EVAR from 2010 -2018 in a single institution. Late endoleaks were defined as those appearing after 1 year. We used Cox regression to study factors associated with late Type 1A endoleaks and survival.

RESULTS

Of 477 EVAR during the study period, 411 (86%) had follow-up imaging, revealing 24 Type 1A endoleaks; 4 early and 20 late. Freedom from Type 1A endoleaks was 99%, 92-81% at 1, 5 and 8 years with a median time to occurrence of 2.5 years (.01-8.2 years). On completion angiogram, only 10% of patients with a late Type 1A had a proximal endoleak, and 60% had no endoleak. Only 21% of late Type 1As were diagnosed on routine 1-year CT angiogram, but 79% had stable or expanding sacs. Two thirds (65%) of the patients eventually diagnosed with late Type 1A endoleaks had previously been treated for other endoleaks, mostly Type 2 (10/13). Age (HR 1.07/year [1.02-1.12], P = 0.01), neck diameter >28mm (HR 3.5 [1.2-10.3], P = 0.02), neck length <20mm (HR 3.0 [1.1-8.6], P = 0.04), and neck angle>60 degrees (HR 3.4 [1.5-7.9], P = 0.004) were associated with higher rates of Type 1A endoleak, but not female sex, endograft, or the use of suprarenal fixation. 2 patients had proximal degeneration and 5 experienced graft migration. There were 2 ruptures (10%), and 13 patients underwent repair with 5 open conversions. Median survival after late Type 1A repair was 6.6 years (0-8.4 years).

CONCLUSION

Late appearing Type 1A endoleaks have a high rate of rupture and present significant diagnostic and management challenges. Careful surveillance is needed in patients with hostile neck anatomy and those who undergo intervention for other endoleaks. Adverse neck anatomy may be better suited for open repair or fenestrated/branched devices rather than conventional EVAR.

The Italian Multicentre Registry of Fenestrated Anaconda™ Endografts for Complex Abdominal Aortic Aneurysms Repair

OBJECTIVE

The aim was to describe the outcomes of the Anaconda™ Fenestrated endograft Italian Registry for complex aortic aneurysms (AAAs), unsuitable for standard endovascular aneurysm repair (EVAR).

METHODS

Between 2012 and 2018 patients with a proximal neck unsuitable for standard EVAR, treated with the fenestrated Anaconda™ endograft, were prospectively enrolled in a dedicated database. Endpoints were peri-operative technical success (TS) and evaluation of type Ia/b or 3 endoleaks (T1/3 EL), target visceral vessel (TVV) occlusion, re-interventions, and AAA related mortality at 30 days, six months, and later follow up.

RESULTS

One hundred twenty seven patients (74 ± 7 years, American Society Anesthesiology (ASA) II/III/IV: 12/85/30) were included in the study in 49 Italian Vascular Surgery Units (83 juxta/para-renal AAA, 13 type IV thoraco-abdominal AAA, 16 T1aEL post EVAR, and 15 short neck AAA). Configurations with one, two, three, and four fenestrations were used in 5, 56, 39, and 27 cases, respectively, for a total of 342 visceral vessels. One hundred and eight (85%) bifurcated and 19 (15%) tube endografts were implanted. In 35% (44/127) of cases the endograft was repositioned during the procedure, and 37% (128/342) of TVV were cannulated from brachial access. TS was 87% (111/127): five T1EL, six T3EL (between fenestration and vessel stent), and six loss of visceral vessels (one patient with a Type Ia EL had also a TVV loss) occurred. Thirty day mortality was 4% (5/127). Two of the five T1EL resolved spontaneously at 30 days. The overall median follow up was 21 ± 16 months; one T1EL (5%) occurred at six months and one T3EL (4%) at the three year follow up. Another two (3%) TVV occlusions occurred at six months and five (3%) at three years. The re-intervention rate at the 30 days, six months, and three year follow up was 5%, 7%, and 18 ± 5%, respectively.

CONCLUSION

The fenestrated Anaconda™ endograft is effective in the treatment of complex AAA. Some structure properties, such as the re-positionability and the possibility of cannulation from above, are specific characteristics helpful for the treatment of some complex anatomies.