Nineteen-year outcomes with the Anaconda stent graft system from two tertiary centers

Fractured Sealing Rings in a Fenestrated Anaconda Stent-Graft

An 81 year-old man presented with an asymptomatic juxtrarenal abdominal aortic aneurysm and was subsequently treated with a fenestrated endovascular Anaconda stent-graft. Surveillance imaging within the first postoperative year demonstrated a lower proximal sealing ring fracture. In the second postoperative surveillance year, the upper proximal sealing ring was also fractured with extension of the wire into the right paravertebral space. Despite these sealing ring fractures, there were no endoleak nor visceral stent complications and the patient continued on standard surveillance protocols. There are an increasing number of reports of fractured proximal sealing rings with the fenestrated Anaconda platform. Those analysing the surveillance scans of patients treated with this device should stay vigilant for the development of this complication.

Endograft Anaconda in Endovascular Aneurysm Repair: A Systematic Review of Literature and Meta-Analysis

BACKGOUND

The number of endovascular abdominal aortic aneurysm repairs (EVARs) has surpassed the number of open surgical repair of AAAs worldwide with a great variety of endografts being available. The aim of this study is to conduct a systematic review of the literature and meta-analysis of studies reporting patients with infrarenal abdominal aortic aneurysm (AAA) subjected to EVAR with the Anaconda endograft.

METHODS

We performed a systematic review of multiple electronic databases for studies including patients with infrarenal AAA who were subjected to elective EVAR with Anaconda endograft exclusively. We conducted a proportional meta-analysis cumulating the results of the included studies. The endpoints were first month overall mortality, first and second-year survival after EVAR, AAA-related deaths, incidence of endoleaks, endograft migration, endograft occlusion, open conversion, and primary and secondary technical success. The mean value for each separate studied factor was calculated, and the respective percentage or incidence was extracted so that it can be compared to endograft outcome studies in the literature. We assessed the methodologic quality of studies by using the Briggs Institute critical appraisal tool.

RESULTS

Seven observational studies were found including 954 patients (males 91.9%, mean age 73.38 ± 6.97 years). The mean transverse diameter of AAAs was 56.83 ± 9.97 mm. The mean proximal aortic neck diameter and length were 23.06 ± 3.33 mm and 24.14 ± 12.16 mm, respectively. Increased aortic neck calcification and aortic neck thrombus were present in 12.5% of patients. The 30-day overall mortality post-EVAR was 1.3%, 1 and 2-year survival rates were 95.9% and 91.4%, respectively. The mean follow-up period in the studies was 46.59 ± 15.5 months. AAA-related mortality was 1.3%. Primary technical success was 97.9% and secondary success was 99.3%. Open conversion was required in 3.4% of all patients (0.6% during the primary operation [Prim. Op]). The most common endoleak was type II, reported in 17.4% of all patients. Early type Ia endoleak was reported in 1.5% of patients and late type Ia in 1.7%. Overall, 2 endoleaks type III and 1 type IV were reported. Endograft migration occurred in 1.7% of patients. Main body and/or one/both iliac legs thrombotic occlusion was found totally in 7.6% of patients (5 main body occlusions and 64 iliac leg occlusions).

CONCLUSIONS

The use of Anaconda endograft in electively treated patients with infrarenal AAAs presented good results with high technical success and low postoperative and mid-term complications, except for an increased incidence of stent-graft thrombosis, which seems to be the "Achilles heel" of the device.

Ultrasound Particle Image Velocimetry to Investigate Potential Hemodynamic Causes of Limb Thrombosis After Endovascular Aneurysm Repair With the Anaconda Device

PURPOSE

To identify potential hemodynamic predictors for limb thrombosis (LT) following endovascular aneurysm repair with the Anaconda endograft in a patient-specific phantom.

MATERIALS AND METHODS

A thin-walled flow phantom, based on a patient's aortic anatomy and treated with an Anaconda endograft, that presented with a left-sided LT was fabricated. Contrast-enhanced ultrasound particle image velocimetry was performed to quantify time-resolved velocity fields. Measurements were performed in the same phantom with and without the Anaconda endograft, to investigate the impact of the endograft on the local flow fields. Hemodynamic parameters, namely vector complexity (VC) and residence time (RT), were calculated for both iliac arteries.

RESULTS

In both limbs, the vector fields were mostly unidirectional during the peak systolic and end-systolic velocity phases before and after endograft placement. Local vortical structures and complex flow fields were observed at the diastolic and transitional flow phases. The average VC was higher (0.11) in the phantom with endograft, compared to the phantom without endograft (0.05). Notably, in both left and right iliac arteries, the anterior wall regions corresponded to a 2- and 4-fold increase in VC in the phantom with endograft, respectively. RT simulations showed values of 1.3 to 6 seconds in the phantom without endograft. A higher RT (up to 25 seconds) was observed in the phantom with endograft, in which the left iliac artery, with LT in follow-up, showed 2 fluid stasis regions.

CONCLUSION

This in vitro study shows that unfavorable hemodynamics were present mostly in the limb that thrombosed during follow-up, with the highest VC and longest RT. These parameters might be valuable in predicting the occurrence of LT in the future.

CLINICAL IMPACT

This in-vitro study aimed to identify potential hemodynamic predictors for limb thrombosis following EVAR using ultrasound particle image velocimetry (echoPIV) technique. It was shown that unfavorable hemodynamic norms were present mostly in the thrombosed limb. Owing to the in-vivo feasibility of the echoPIV, future efforts should focus on the evaluation of these hemodynamic norms in clinical trials. Thereafter, using echoPIV as a bedside technique in hospitals becomes more promising. Performing echoPIV in pre-op phase may provide valuable insights for surgeons to enhance treatment planning. EchoPIV is also applicable for follow-up sessions to evaluate treatment progress and avoid/predict complications.

Geometrical Changes of the Aorta as Predictors for Thromboembolic Events After EVAR With the Anaconda Stent-Graft

PURPOSE

Thromboembolic events (TE), including limb graft occlusion (LGO) and distal limb embolization (DLE), are common complications after endovascular aneurysm repair (EVAR). The aim of this study was to find predictors for TE in patients treated with the Anaconda stent-graft for infrarenal aneurysms.

MATERIALS AND METHODS

Geometrical and anatomical variables were retrospectively analyzed in a consecutive Anaconda cohort. Pre- and postoperative CT scans were used to derive geometrical parameters length, curvature, torsion, and tortuosity index (TI) from the center lumen lines (CLLs). Limb characteristics, pre-to-post EVAR and mid-term-follow-up changes in the parameters were evaluated for their predictive value for TE.

RESULTS

Eighty-four patients (mean age 74±8.3 years, 74 men) were enrolled. The risk of TE was lowered with pre-to-post implant decreasing TI (steps of 0.05: OR: 1.30, 95% CI: 1.01-1.66, p=0.04), pre-to-post implant decreasing mean curvature (OR: 1.08, 95% CI: 1.01-1.16, p=0.03), and a larger degree of circumferential common iliac artery (CIA) calcification (OR: 0.98, 95% CI: 0.97-1.00, p=0.03). The only LGO predictor was the caudal relocation of maximal curvature after EVAR (OR: 1.01, 95% CI: 1.00-1.01, p=0.04). Preventors of DLE were CIA diameter (OR: 0.87, 95% CI: 0.76-0.99, p=0.04), circumferential CIA calcification (OR: 0.97, 95% CI: 0.95-1.00, p=0.03), mean and maximal curvature of the preoperative aortoiliac trajectory (OR: 0.86, 95% CI: 0.79-0.94, p<0.01 and OR: 0.97, 95% CI: 0.95-1.00, p=0.03, respectively) and pre-to-postoperative decrease in mean curvature (OR: 1.11, 95% CI: 1.02-1.21, p=0.02). Midterm TE predictors were length (OR: 0.95, 95% CI: 0.89-1.01, p=0.08) and torsion maximum location (OR: 1.01, 95% CI: 0.99-1.01, p=0.10).

CONCLUSION

The present study confirms that treatment of infrarenal AAA with an Anaconda stent-graft is related to a relatively high TE rate which decreases with a pre-to-postoperative reduction in curvature and TI, and a larger degree of circumferential CIA calcification. In other words, more aortoiliac straightening and more circumferential CIA calcification may prevent TE development after EVAR with this stent-graft.

Impact of patient demographics and intraoperative characteristics on abdominal aortic aneurysm sac following endovascular repair

BACKGROUND

Endovascular aortic repair (EVAR) has become the preferred treatment for abdominal aortic aneurysm (AAA). Its main aim is to seal the perfusion of the aneurysmal sac and, thus, induce sac regression and subsequent aortic remodelling. Aneurysmal sac regression has been linked to the short- and long-term clinical outcomes post-EVAR. It has also been shown to be influenced by endograft device choice, with several of these available commercially. This review summarises and discusses current evidence on the influence of pre- and intraoperative factors on sac regression. Additionally, this review aims to highlight the device-specific variations in sac regression to provide an overall holistic approach to treating AAAs with EVAR.

METHODS

A comprehensive literature search was conducted using multiple electronic databases to identify and extract relevant data.

RESULTS

Female sex, >70 mm original sac diameters, higher pre-procedural fibrinogen levels, smoking and low intra-aneurysmal pressure were found to positively impact sac regression. Whereas renal impairment, ischemic heart disease, high intra-aneurysmal pressure and aneurysm neck thrombus negatively influenced sac regression. Patent lumbar arteries, age, statins and hypercholesterolaemia displayed conflicting evidence regarding sac regression. Regarding the EVAR endografts compared, newer generation devices such as the Anaconda mainly showed the most optimal results.

CONCLUSION

Sac regression following EVAR in AAA is an important prognostic factor for morbidity and mortality. Nevertheless, several pre- and intraoperative factors can have an influence on sac regression. Therefore, it is necessary to take them into account when assessing AAA patients for EVAR to optimise outcomes. The choice of EVAR stent-graft can also affect sac regression, with evidence suggesting that the Fenestrated Anaconda is associated with the most favourable results.

Patient longevity and survival with custom-made endovascular solutions: The Fenestrated AnacondaTM approach

BACKGROUND

Endovascular aortic repair (EVAR) has become the mainstay treatment for abdominal aortic aneurysms and is associated with excellent clinical outcomes. However, there remains a risk of complications requiring reintervention. Several EVAR devices exist commercially, yet, the Terumo Aortic Fenestrated Anaconda™ has demonstrated outstanding results. The main scope of this study is to evaluate survival/longevity, target vessel patency (TVP), endograft migration and reintervention following Fenestrated Anaconda™ implantation and discuss relevant literature.

METHODS

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

RESULTS

A total of 5058 patients received the Fenestrated Anaconda™ endograft. The Fenestrated Anaconda™ was indicated either due to complex anatomy for competitor devices (n = 3891, 76.9%) or based on surgeon preference (n = 1167, 23.1%). Both survival and TVP were 100% during the first 6 postoperative years but dropped to 77.1% and 81% thereafter. In the complex anatomy indication group, cumulative survival and TVP were both 100% until year 7 post-EVAR when they decreased to 82.8% and 75.7%. In the other indication group, survival and TVP were also 100% during the first 6 years but plateaued at 58.1% and 98.8% in years 7-9 of follow-up. No cases of endograft migration and reintervention were recorded.

CONCLUSION

The Fenestrated Anaconda™ has been proven across the literature to be a highly effective EVAR endograft, as it has demonstrated excellent survival/longevity and TVP as well as minimal endograft migration and reintervention.

Correlative effect between sac regression and patient longevity following endovascular solution for abdominal aortic aneurysms: an international analysis

INTRODUCTION

Since the introduction of endovascular aortic repair (EVAR) it has become the mainstay treatment for abdominal aortic aneurysms. Several EVAR devices exist commercially, yet, the Terumo Aortic Fenestrated Anaconda™ endograft has demonstrated outstanding results. Evidence in the literature suggests that sac regression could be linked to patient survival and longevity. The main scope of this study is to evaluate sac regression and survival achieved using the Fenestrated Anaconda™ endograft and to discuss relevant literature.

MATERIALS AND METHODS

The current study represents a nine-year cross-sectional international analysis of 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

A total of 5,058 patients received the Fenestrated Anaconda™ in this study, either due to unsuitable/complex anatomy for competitor devices (n = 3,891) or based on surgeon preference (n = 1,167). A sac regression of 0-30% was observed in 4,772 (94.3%) over the first four years post-EVAR. Here, 99.6% of patients receiving the Fenestrated Anaconda™ due to unsuitable/complex anatomy for competitor devices and 76.8% based on surgeon preference had 0-30% sac regression. During years 5-9 of follow-up, all patients had 20-45% sac regression. Patient survival during the first six years post-EVAR was 100% but dropped to 77.1% in years 7-9. Survival differed between categorical patient subsets based on the indication.

DISCUSSION

The Fenestrated Anaconda™ has been proven to be a highly effective EVAR endograft. Evidence in the literature clearly demonstrates that sac regression is an accurate prognostic factor for patient survival and longevity.

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.

Abdominal Aortic Aneurysm: Can the Anaconda™ Custom-Made Device Deliver? An International Perspective

Introduction

Since the introduction of endovascular aortic repair (EVAR), it has demonstrated excellent clinical outcomes and has replaced open surgical repair (OSR) in the treatment of abdominal aortic aneurysms (AAA). AAA is a life-threatening abnormal dilation of the abdominal aorta to 1.5 times its normal diameter. Several commercial EVAR devices exist on the global market, with the Terumo Aortic Fenestrated Anaconda™ graft showing superiority. In this study, we sought to provide an international perspective using multicenter-multinational data on the Anaconda™ device characteristics, design, and delivery, and discuss relevant literature.

Materials and Methods

This study represents a cross-sectional international analysis of custom-made fenestrated Anaconda™ device. Ethical and legal approval for data collection was obtained from each of the local authorities. For the statistical analysis, SPSS 28 for Windows and R were utilized. Pearson’s 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

A total of 5,030 Anaconda™ devices were implanted during the 9-year study period in 27 countries spanning 6 continents. The predominant device category was bifurcate (83.6%), whereas the most common proximal ring stent configuration being standard (64.5%). All devices were delivered within 8 weeks of diagnosis, with most being implanted within 6–8 weeks (55.4%). The Anaconda™ was indicated in the 3,891 (77.4%) patients due to competitor rejection/inability to treat unsuitable/complex aortic anatomy. In the remaining 1,139 (22.6%) patients, it was utilized based on surgeon preference. Almost all devices (95%) were delivered along with a prototype. Of the total 5,030 Anaconda™ devices, 438 (8.7%) used 0–1 fenestrations, 2,349 (46.7%) used 2–3, while 2,243 (44.6%) utilized 4, 5, or 6 fenestrations.

Discussion

The Terumo Aortic Fenestrated Anaconda™ device features a highly unique and innovative design that enables it to treat highly complex aortic anatomy while achieving excellent results. The Anaconda™’s custom-made approach allows it to be tailored to individual patient anatomy, in addition to the device prototype provided by Terumo Aortic optimize clinical outcomes. Finally, the fenestrated Anaconda™ is a highly versatile device offering a wide range of device categories, configurations, and sizes.

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.