Outcomes after treatment of complex aortic abdominal aneurysms with the fenestrated Anaconda endograft

Early Results of Fenestrated and Branched Endovascular Repair of Complex Aortic Aneurysms with a Custom-made National Device Available in the Brazilian Public Health System

BACKGROUND

Multicenter studies conducted in developed countries demonstrated that custom-made devices are safe, effective, and durable for treating complex abdominal aneurysms. However, the situation in developing countries, such as Brazil, is different. Funding and time to have the endoprosthesis delivered are the major concerns. In order to overcome these conditions, high-volume Brazilian university hospitals started gaining experience with a custom-made device produced in the country.

OBJECTIVE

The present study aimed to describe the practice of 2 tertiary centers and report the early results of fenestrated and branched endovascular repair of complex aortic aneurysms with a custom-made national device available in the Brazilian public health system.

METHODS

Retrospective analysis of all consecutive patients that underwent fenestrated and branched endovascular aneurysm repair (F/BEVAR) of complex aortic aneurysms using custom-made manufactured endoprosthesis in 2 tertiary centers from January 2020 to July 2022.

RESULTS

Thirteen cases were included (10 male, mean age 69 ± 9 years). 70% were complex abdominal aneurysms, and 30% were type II, III, and IV thoracoabdominal aneurysms (mean aneurysm diameter 69.2 ± 8.12 mm). F/BEVAR included 33 visceral arteries. The Apolo® device was used in all cases. Technical success was achieved in 12 out of 13 patients (92.3%). Thirty-day major adverse events included one death (7.7%), 5 acute renal failure (38.4%), 2 spinal cord ischemia (15.4%). The 1-year survival rate was 92.3%.

CONCLUSIONS

Fenestrated and branched endovascular repair of complex aortic aneurysms with the custom-made Apolo® device has proven safe and effective in high-volume tertiary centers in the Brazilian public health system. Considering the complexity of the cases, the early patency of vessels and low initial mortality support this device continuation and expansion to treat complex aortic aneurysms in a developing country.

The Anaconda One-LokTM stent graft for the treatment of infrarenal abdominal aortic aneurysms: clinical results, technical, and mechanical characteristics

INTRODUCTION

The Anaconda aortic stent graft is a trimodular endovascular stent graft with an active infrarenal fixation suitable for the treatment of infrarenal abdominal aortic aneurysms with an infrarenal neck angulation ≤90°. A unique magnet-based mechanism facilitates the cannulation of the contralateral leg.

AREAS COVERED

The present article provides a complete description of the third-generation Anaconda endograft, the Anaconda One-LokTM, its clinical performance and the related technical and mechanical characteristics as well as a brief comparison between itself and other similar endografts.

EXPERT OPINION

The Anaconda One-Lok stent graft is particularly suitable for abdominal aortic aneurysms with an infrarenal aortic neck angulation up to 90°. Issues that need to be resolved concern the higher incidence of iliac limb occlusion and distal migration compared to other commercially available endografts and possibly the valley central migration with the risk of covering the renal ostia.

Fenestrated Endovascular Aortic Repair of Complex Aneurysm Using the Anaconda Fenestrated Device: 1-Year Results From the French Multicenter Registry

PURPOSE

This study aims to assess the safety and efficacy of the fenestrated Anaconda device for the treatment of complex aortic aneurysms over 1 year in daily clinical practice.

MATERIALS AND METHODS

All patients who received the graft between October 2019 and October 2020 were prospectively enrolled in an observational, multicenter national registry. The primary endpoint was the aneurysm-related 1-year mortality rate. Secondary endpoints included all-cause mortality, technical success, device-related adverse events (AEs) and major complications, secondary reinterventions, endoleaks, target vessel (TV) outcomes, and a center-volume analysis comparing mortality and secondary reintervention rate between expert centers (>15 F/BEVAR per year) and nonexpert centers (≤15 F/BEVAR per year).

RESULTS

Ninety-seven patients from 28 centers were treated. Aneurysms types included juxta-renal and short neck (84.6%), pararenal (5.2%), paravisceral (3.1%), and type IV thoracoabdominal (2.5%). Configurations with 1, 2, 3, and 4 fenestrations were used in 2, 12, 18, and 65 cases, respectively, totaling 350 TVs. Technical success was 98.0%, with 1 type Ic and 1 type IIIc endoleak. Mean follow-up was 468 days. Ten patients died, with 8 deaths (8.2%) due to non-aortic causes and 2 deaths (2.1%) from unknown causes. The estimated 1-year survival rate was 92.7% (95% CI: 87.8-98.1%). The reintervention rate at 30 days was 11.3% and the estimated reintervention rate at 1 year was 21.6% (95% CI: 12.7-29.6%). No type Ia endoleak occurred during follow-up. Three type III endoleaks occurred and required reintervention. Three TV occlusion occurred, yielding a 1-year TVI-free rate of 92.4% (95% CI: 89.4-99.3). No device-related major complication was recorded, and 3 device-related AEs occurred: 1 limb migration, 1 limb kinking and 1 limb thrombosis. There was no statistically significant difference in mortality and survival without reintervention between expert and nonexpert centers (Log rank p=0.52 and p=0.16, respectively).

CONCLUSION

The fenestrated Anaconda device demonstrated acceptable early and at 1-year safety and efficacy for treating primarily juxta-renal and short-neck aortic aneurysms, in centers with varying levels of experience.

CLINICAL IMPACT

The Anaconda Fenestrated, as the second commercially available custom-made device for complex endovascular aortic surgery, might adress some anatomical challenges. Following market authorization, this registry presents the 1-year outcomes of real-world device usage in a large number of centers, including small clinics. The results indicate that the device provided adequate efficacy and safety for treating mostly juxta-renal and short neck aneurysms, with notable improvement in technical success rate compared to older reports.

Short-term outcomes of endovascular aortic aneurysm repair with the new Braile Biomédica® total custom-made abdominal endograft: Experience from three Italian centers

INTRODUCTION

Since 2019, Braile Biomédica® introduced a novel custom-made abdominal endograft tailored to the aorta's anatomy, featuring sizing every 3 mm and a diameter change from 50 mm to 8 mm. This design permits uncovered fenestrations around a single Z stent, eliminating the need for bridging stents to visceral vessels. Utilizing triple stent technology, optimal neck fixation is ensured, enabling treatment of necks shorter than 2 mm, with three 360° fenestrations optimizing graft fixation. This paper aims to analyze the initial experience with this custom-made infrarenal graft for abdominal aorta aneurysm (AAA), concerning procedural success and post-procedural short-term outcomes.

RESULTS

Among 12 patients treated from May 2022 to January 2024, technical success was achieved in 91.7 %, with only one intra-procedural complication. Follow-up CT scans at 1-3 months revealed resolution of an intraoperative endoleak and two late complications: a late type III endoleak and right renal artery occlusion.

CONCLUSIONS

The recent experience with Braile Biomédica® custom-made abdominal endograft demonstrates promising outcomes, particularly in treating AAAs with challenging anatomical features.

Early Institutional Experience with One-Piece Bifurcated-Fenestrated Stentgraft in the Treatment of Abdominal Aortic Aneurysms

PURPOSE

To review the early experience of the use of a bifurcated-fenestrated endograft (Bif-FEVAR) to treat abdominal aortic aneurysms (AAA) in a high-volume aortic center.

METHODS

A retrospective single-center analysis was conducted between March 2019 and April 2021 including consecutive patients that underwent Bif-FEVAR. Only patients without a proper infrarenal neck and a distance <70 mm between the lowest target artery and the native or prosthetic aortic bifurcation were considered. All Bif-FEVAR custom-made devices were manufactured by Cook Medical (Inc., Bloomington, Indiana). Demographics, anatomical features, technical success, major adverse events, 30-day mortality, and survival according to Kaplan-Meier were analyzed according to Society for Vascular Surgery standards.

RESULTS

Overall, 10 patients (100% male with median age 78) were included. The median preoperative maximal aneurysm diameter was 68 mm [51-84]. Eight patients were treated for a proximal type I endoleak after endovascular aneurysm repair. A total of 36 fenestrations were planned. The median operative time was 144 min [127-168], with a median fluoro time of 40.5 min [34-54] and a median dose area product of 73 Gy cm2 [61-89]. Technical success rate was 100%. No patients experienced a major postoperative adverse event. Median follow-up time was 8 months [6-13].

CONCLUSION

Bif-FEVAR is technically feasible when there is a short distance below the lowest target artery and the aortic bifurcation, with favorable short-term results.

CLINICAL IMPACT

This study assessed the use of an innovative one-piece bifurcated fenestrated stent-graft as a primary procedure or in the treatment of proximal endoleak after standard infrarenal EVAR. We demonstrated these custom-made devices can be used safely with favorable short-term results. One-piece bifurcated fenestrated stent-grafts extend the indications of FEVAR for patients with an unusually short distance between the lowest renal artery and the aorto-iliac bifurcation or the diverter flow of a preexisting bifurcated infrarenal stent-graft.

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.

Fenestrated Physician-Modified Endografts for Preservation of Main and Accessory Renal Arteries in Juxtarenal Aortic Aneurysms

BACKGROUND

There is a paucity of reporting outcomes of complex aortic aneurysm treatment such as juxtarenal abdominal aortic aneurysms, where additional techniques to preserve renal artery perfusion are required.

METHODS

Retrospective analysis of consecutive patients who underwent emergent and elective aortic repair with fenestrated PMEGs between March 2019 and January 2023. Endpoints were technical success, reinterventions, secondary reinterventions and target vessel patency.

RESULTS

Forty-seven target vessels in 37 patients (23 male, median age 75 years) were targeted, of which 44 were renal arteries (RAs) with a mean diameter of 5.4 ± 1.0 mm. Thirteen were accessory RAs and six had a diameter ≤ 4 mm. Technical success rate was 87% overall; 97% for main and 62% for accessory RAs respectively. Target vessel patency and freedom from secondary reintervention was 100% and 97% at 30 days and 96% and 91% at one year, respectively. There was no 30-day mortality.

CONCLUSION

Fenestrated physician-modified endografts are safe and effective for the treatment of patients with juxtarenal abdominal aortic aneurysms when incorporating main renal arteries. Limited technical success may be expected when targeting accessory renal arteries, especially when small in diameter. Long-term follow-up is needed to confirm durability of PMEGs for renal artery preservation.

Three-Dimensional Geometric Analysis of Balloon-Expandable Covered Stents Improves Classification of Complications after Fenestrated Endovascular Aneurysm Repair

In balloon-expandable covered stent (BECS) associated complications after fenestrated endovascular aneurysm repair (FEVAR), geometric analysis may determine the cause of failure and influence reintervention strategies. This study retrospectively classifies BECS-associated complications based on computed tomographic angiography (CTA) applied geometric analysis. BECS-associated complications of FEVAR-patients treated in two large vascular centers between 2012 and 2021 were included. The post-FEVAR CTA scans of complicated Advanta V12 BECSs were analyzed geometrically and complications were classified according to its location in the BECS. BECS fractures were classified according to an existing classification system. In 279 FEVAR-patients, 34 out of the 683 included Advanta V12 BECS (5%) presented with a complication. Two Advanta V12 complications occurred during the FEVAR procedure and 32 occurred during follow-up of which five post-FEVAR CTA scans were missing or not suitable for analysis. In the remaining 27 BECSs complications were classified as (endoleaks (n = 8), stenoses (n = 4), occlusions (n = 6), fractures (n = 3), and a combination of complications (n = 6)). All BECSs associated complications after FEVAR with available follow up CTA scans could be classified. Geometric analysis of BECS failure post-FEVAR can help to plan the reintervention strategy.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

OBJECTIVE

Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes.

METHODS

We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected.

RESULTS

Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality.

CONCLUSIONS

Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

Fenestrierte und verzweigte endovaskuläre Aortenprothesen

Hintergrund

Komplexe abdominelle aortale Pathologien, welche die Abgänge der Viszeralarterien miterfassen und bei denen kein adäquater proximaler Hals gegeben ist, können heute mittels fortgeschrittener FEVAR/BEVAR-Technik („fenestrated/branched endovascular aneurysm repair“) mit ähnlicher Sicherheit und vergleichbaren Erfolgsraten behandelt werden wie infrarenale Pathologien mit konventionellem EVAR.

Methodische Innovationen und Probleme

Zur Versorgung der Viszeralarterien können Fenestrierungen (bei Abgang der Viszeralarterie aus der nichtdilatierten Aorta) oder Verzweigungen (bei Abgang aus der dilatierten Aorta) verwendet werden. Beide Arten von Öffnungen werden mit Verbindungsstentgrafts (VSG) zu den Viszeralarterien abgedichtet. Mehrere Hersteller bieten fenestrierte oder verzweigte Endoprothesen an, wobei diese nur in Einzelfällen CE-zertifiziert und überwiegend in Europa als individuelle Sonderanfertigungen patientenbezogen erhältlich sind. Dies setzt eine entsprechende Lieferzeit voraus, was die Behandlung akuter Patienten mit solchen Prothesen unmöglich macht. Es liegen allerdings zwei Produkte von vierfach verzweigten Endoprothesen vor, die einen größeren Bereich der anatomischen Gegebenheiten bei thorakoabdominellen Aneurysmen auch im Akutfall abdecken und behandelbar machen. Sämtliche FEVAR- und BEVAR-Hauptkörper benötigen VSG, die durchgehend von Fremdherstellern stammen und von denen gegenwärtig noch kein einziges Produkt für diese Anwendung zertifiziert ist.

Empfehlungen

Da Probleme an Verbindungsstentgrafts eine wesentliche Ursache für Reinterventionen sind, sollte in der Nachsorge Knickbildungen und Brüchen an diesen Verbindungsstents besonderes Augenmerk geschenkt und von der Verwendung einschichtiger Designs beim BEVAR abgesehen werden.

Cannulation of visceral vessels using a steerable sheathin fenestrated and branched aortic endografts

INTRODUCTION

A critical step in the endovascular treatment of complex aortic aneurysm is the cannulation and stenting of renovisceral vessels, especially in cases with a complex anatomy or atherosclerotic lesions. This study aimed to demonstrate the results of renovisceral vessel cannulation using a steerable sheath in fenestrated or branched endovascular aortic procedures (FB-EVAR).

METHODS

Patients undergoing elective FB-EVAR for asymptomatic thoracoabdominal or juxtarenal aneurysm at a single tertiary referral center from 2016 to 2019 were included in this study. Underlying pathologies, renovisceral target vessels (TV), technical success (TS), freedom from reintervention (FFR), and TV patency were assessed. Target vessels were categorized as challenging or non-challenging TV.

RESULTS

Fifty-three patients (median age 73 (Q1, Q3 (68 - 80)); 43 male (81%)) who underwent elective FB-EVAR were included. Indications comprised thoracoabdominal aneurysms (Crawford I-IV) (n = 26; 49%), juxtarenal aneurysms (n = 23; 43.5%) and penetrating aortic ulcers (PAU) (n = 4; 7.5%). Two patients (4%) had prior open aortic surgery, and three patients (6%) had undergone a failed standard EVAR before. Of the 196 treated TV, 131 (67%) were categorized as challenging. Cannulation was successful in 194 of 196 vessels (99%). A total of three TV (1.5%) showed periprocedural complications. No significant difference was found in the rate of intraoperative complications between challenging versus non-challenging TV (p = 0.457). One patient died within 30 days of the procedure (1.9%). No stroke or intestinal ischemia occurred. After 12, 24, and 36 months, the survival rate was 87%, 87%, and 81%, respectively Primary patency after 12 months was 98.6%, and 97.9% of vessels remained FFR during follow-up.

CONCLUSION

Transfemoral, retrograde cannulation of renovisceral vessels using a steerable sheath is feasible and safe and provides good mid-term results, especially in cases with challenging renovisceral vessels. The potential complications of antegrade vascular access can be avoided.

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.

Mechanical Behaviour of Fenestrations in Current Aortic Endografts

OBJECTIVE

The aim of this study was to assess the mechanical characteristics of current commercially available fenestrated endografts (FE). The performance of the fenestrations according to the design were compared as the relationship between a bridging covered stent graft (CSG) and the fenestration.

METHODS

A total of 21 Zenith (Cook Medical, Bloomington, IN, USA) and 17 Anaconda (Terumo Company, Inchinnan, UK) fenestrations were studied. Radial extension tests were performed, inserting two half cylinders spaced up to 2 mm in a 7 mm diameter fenestration from each device. Branch pull out force was measured to test the stability of the assembly with a calibrated 8 mm branch and two CSGs: Advanta V12 (Atrium Medical; Hudson, NH, USA) and BeGraft Peripheral Stent Graft (Bentley InnoMed GmbH, Hechingen, Germany). A branch was inserted in both the 7 mm diameter fenestrations and in a control 7 mm fenestration. Fatigue tests were performed on the devices to assess long term outcomes of the endograft.

RESULTS

Over a 2 mm vertical displacement, the resulting loading curves look similar for both devices. The force value level was 33.4 ± 6.9 N for the Cook fenestration and 54.45 ± 18 N for the Anaconda fenestration (p = .001). With respect to an 8 mm calibrated branch, the required extraction strength from the fenestration was statistically significantly greater with the Anaconda device (9.5 ± 4.7 N vs. 4.49 ± 0.28 N; p = .001). The required strength to extract the V12 CSG from a control cylindered shape was statistically significantly higher than for the BeGraft CSG (6.75 ± 2.86 N vs. 1.83 ± 0.67 N; p = .003). The surface area of the fenestration of the Cook device was increased with cycling (7 200 cycles) compared with the Anaconda device (15.5% vs. 6.5% hole surface area increase).

CONCLUSION

The mechanical performance of the fenestration can be fine tuned by considering its design. A CSG optimising the performance of the fenestration and the CGS-fenestration interface could reduce the risk of leakage in clinical practice.

Custom-made fenestrated stent for mycotic aortic aneurysms: a report of two cases

Background

Mycotic aortic aneurysm is a rare and potentially life-threatening lesion, and endovascular repair has become increasingly accepted for intervention. Fenestrated endografts are available options to treat aneurysms involving visceral arteries. Here, we first report two patients with mycotic aortic aneurysm involving paraviscereal aorta who were successfully treated with custom-made fenestrated endograft.

Case presentation

Two patients were presented with mycotic aortic aneurysm. Due to their comorbidities and the involvement of the renal arteries, company-manufactured fenestrated stents were designed. Meanwhile, antibiotic therapy was administrated for 2 months before endovascular repair. Patients improved well without complications.

Conclusions

Custom-made fenestrated endovascular stent is an effective and feasible alternative solution to mycotic paravisceral aorta aneurysm.

Assessment of fenestrated Anaconda stent graft design by numerical simulation: Results of a European prospective multicenter study

OBJECTIVE

A crucial step in designing fenestrated stent grafts for treatment of complex aortic abdominal aneurysms is the accurate positioning of the fenestrations. The deployment of a fenestrated stent graft prototype in a patient-specific rigid aortic model can be used for design verification in vitro, but is time and human resources consuming. Numerical simulation (NS) of fenestrated stent graft deployment using the finite element analysis has recently been developed; the aim of this study was to compare the accuracy of fenestration positioning by NS and in vitro.

METHODS

All consecutive cases of complex aortic abdominal aneurysm treated with the Fenestrated Anaconda (Terumo Aortic) in six European centers were included in a prospective, observational study. To compare fenestration positioning, the distance from the center of the fenestration to the proximal end of the stent graft (L) and the angular distance from the 0° position (C) were measured and compared between in vitro testing (L1, C1) and NS (L2, C2). The primary hypothesis was that ΔL (|L2 - L1|) and ΔC (|C2 - C1|) would be 2.5 or less mm in more than 80% of the cases. The duration of both processes was also compared.

RESULTS

Between May 2018 and January 2019, 50 patients with complex aortic abdominal aneurysms received a fenestrated stent graft with a total of 176 fenestrations. The ΔL and ΔC was 2.5 mm or less for 173 (98%) and 174 (99%) fenestrations, respectively. The NS process duration was significantly shorter than the in vitro (2.1 days [range, 1.0-5.2 days] vs 20.6 days [range, 9-82 days]; P < .001).

CONCLUSIONS

Positioning of fenestrations using NS is as accurate as in vitro and could significantly decrease delivery time of fenestrated stent grafts.

Prospective Multicentre Cohort Study of Fenestrated and Branched Endografts After Failed Endovascular Infrarenal Aortic Aneurysm Repair with Type Ia Endoleak

OBJECTIVE

Failed endovascular infrarenal aortic aneurysm repair (EVAR) due to development of late type Ia endoleak exposes patients to the risk of rupture and should be treated. The purpose of this study was to evaluate the results of fenestrated/branched EVAR (F/BEVAR) for treatment of failed EVAR with type Ia endoleak.

METHODS

From January 2010 to December 2019, a prospective multicentre study was conducted (ClinicalTrials.gov identifier: NCT04532450) that included 85 consecutive patients who had undergone F/BEVAR to treat a type Ia endoleak following EVAR. The primary outcome was overall freedom from any re-intervention or death related to the F/BEVAR procedure.

RESULTS

In 30 cases (35%) EVAR was associated with a short < 10 mm or angulated (> 60°) infrarenal aortic neck, poor placement of the initial stent graft (n = 3, 4%), sizing error (n = 2, 2%), and/or stent graft migration (n = 7, 8%). Type Ia endoleak was observed after a period of 59 ± 25 months following EVAR. The authors performed 82 FEVAR (96%) and three BEVAR (4%) procedures with revascularisation of 305 target arteries. Overall technical success was 94%, with three failures including one persistent Type Ia endoleak and two unsuccessful stent graft implantations. Intra-operative target artery revascularisation was successful in 303 of 305 attempts. The in hospital mortality rate was 5%. Cardiac, renal and pulmonary complications occurred in 6%, 14%, and 7% of patients, respectively. Post-operative spinal cord ischaemia occurred in four patients (4.7%). At three years, the survival rate was 64% with overall freedom from any re-intervention or aneurysm related death of 40%, and freedom from specific F/BEVAR re-intervention of 73%. At three years, the secondary patency rate of the target visceral arteries was 96%. During follow up, 27 patients (33%) required a revision procedure of the fenestrated (n = 11) or index EVAR stent graft (n = 16), including six open conversions.

CONCLUSION

While manufactured F/BEVAR was effective in treating type Ia endoleak in patients with failed EVAR, it was at the cost of a number of secondary endovascular and open surgical procedures.

Exclusion of complex aortic aneurysm with chimney endovascular aortic repair is applicable in a minority of patients treated with fenestrated endografts

OBJECTIVES

The Medtronic Endurant II stent graft has recently received Conformité Européenne (CE) approval for the use in chimney endovascular aortic repair (ChEVAR) for the treatment for juxtarenal aortic aneurysms. The aim of this study was to assess the percentage of patients treated by fenestrated endovascular repair who would have been alternatively suitable for the treatment by the CE approved Medtronic ChEVAR.

METHODS

Preoperative computed tomography scans of 100 patients who underwent fenestrated endovascular aortic repair (FEVAR) between April 2013 and February 2017 were retrospectively assessed for the applicability of the ChEVAR technique according to the Medtronic instructions for use. Eligibility criteria included an aortic neck diameter of 19-30 mm, a minimum infrarenal neck length of 2 mm, a total proximal sealing zone of at least 15 mm, thrombus in the aortic neck in ˂25% of the circumference, and maximum aortic angulations of 60° in the infrarenal, 45° in the suprarenal segment and ˂45° above the superior mesenteric artery.

RESULTS

According to CE-approved inclusion criteria, 19 individuals (19%) would have been eligible for ChEVAR. In 81 patients, at least 1 measure was found outside instructions for use: (i) excluding factor was detected in 26 patients, (ii) incongruous measures in 28 patients and in 27 patients, 3-5 measures were outside the instructions for use. The most frequently identified excluding factor was an insufficient infrarenal neck at ˂2 mm length (n = 63; 63%).

CONCLUSIONS

Patients with juxta- or pararenal aneurysm treated by FEVAR are in 19% of the cases alternatively suitable for the treatment by ChEVAR within CE-approved instructions for use. While ChEVAR is suitable in many emergency cases, FEVAR offers a broader applicability in an elective setting.

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.