Midterm outcome of EndoAnchors for the prevention of endoleak and stent-graft migration in patients with challenging proximal aortic neck anatomy

The Impact of Heli-FX EndoAnchor Application on Endograft Material: An Experimental Study

Objective

The physical impact of the application of Heli-FX EndoAnchors (EA; Medtronic, Minneapolis, USA) on endograft (EG) material is unclear. This study aimed to examine the possible EG membrane alterations after EA implantation.

Methods

Heli-FX EndoAnchors were applied in vitro into four aortic endocuffs: AFX2 (Endologix Inc., Irvine, USA); Endurant II (Medtronic, Minneapolis, USA); Gore Excluder (W.L. Gore and Assoc., Flagstaff, USA); and Zenith Renu (Cook Aortic Interventions, Bloomington, USA). Two of these, Endurant II and Renu, are made of polyethylene terephthalate (PET), while Excluder and AFX2 are made of expanded polytetrafluoroethylene (ePTFE). The penetration angle was measured for each EA. The EAs were then carefully removed, and perforations examined with digital and fluorescent microscopy. The area and perimeter of the holes were digitally calculated, and material alterations were analysed.

Results

Of the 13 EAs applied, 12 remained in place. The mean penetration angle was 79°. The ePTFE perforations had oval openings, while PET perforations were round. After EA removal, comparisons between ePTFE and PET material perforations suggested a larger hole area (p = 0.011) and perimeter (p = 0.003) in the former. The ePTFE perforations in the AFX2 were the largest compared with the holes in other endocuffs (p = 0.050). The perforation channel of the ePTFE membrane of the Excluder cuff retained its form after EA removal. Local dissection like layer damage extended further. The perforations in both the Endurant II and the Renu endocuffs shared similar characteristics, with multiple fibres of PET elongated, distorted, or ruptured.

Conclusion

During EA placement, the EG membrane undergoes local alteration and or destruction. Expanded PTFE, particularly AFX2 endocuffs (for which EA use is not recommended), are characterised by a more extensive degree of material alteration compared with PET. Additional studies are required to chronologically supplement these findings in fatigue tests.

Endosutured Aneurysm Repair of Abdominal Aortic Aneurysms with Short Necks Achieves Acceptable Midterm Outcomes-Results from the Peru Registry

BACKGROUND

The study aims to describe midterm outcomes following treatment of infrarenal abdominal aortic aneurysms (AAAs) with short necks by endosutured aneurysm repair using the Heli-FX EndoAnchor system.

METHODS

This is a retrospective study of prospectively collected data from 9 vascular surgery departments between June 2010 and December 2019, including treated AAAs with neck lengths ≤10 mm. The decision for the use of EndoAnchors was made by the treating surgeon or multidisciplinary aortic committee according to each center's practice. There were 2 Groups further assessed according to neck length, A (≥4 and <7 mm) and B (≥7 and ≤10 mm). The main outcomes analyzed were technical success, freedom from type Ia endoleaks (TIaELs), sac size increase, all-cause and aneurysm-related mortality.

RESULTS

Seventy-six patients were included in the study, 17 fell into Group A and 59 into Group B. Median follow-up for the cohort was 40.5 (interquartile range 12-61) months. A median of 6 (interquartile range 3) EndoAnchors were deployed in each subject. Technical success was 86.8% for the total group, 82.4% and 88.1% (P = 0.534) for Groups A and B respectively. Six out of 10 (60%) of TIaELs at the completion angiographies showed spontaneous resolution. Cumulative freedom from TIaEL at 3 and 5 years for the total group was 89% and 84% respectively; this was 93% and 74% for Group A and 88% at both intervals in Group B (P = 0.545). In total, there were 7 (9.2%) patients presenting with TIaELs over the entire study period. Two (11.8%) in Group A and 5 (8.5%) in Group B (P = 0.679). There were more patients with sac regression in Group B (Group A = 6-35.3% vs. Group B = 34-57.6%, P = 0.230) with no statistical significance. All-cause mortality was 19 (25%) patients, with no difference (4-23.5% vs. 15-25.4%, P = 0.874) between groups; whereas aneurysm-related mortality occurred in 1 patient from Group A and 3 from Group B.

CONCLUSIONS

This study demonstrates reasonable outcomes for patients with short-necked AAAs treated by endosutured aneurysm repair in terms of TIaELs up to 5-year follow-up. EndoAnchor use should be judiciously evaluated in short necks and may be a reasonable option when anatomical constraints are encountered, mainly for those with 7-10 mm neck lengths. Shorter neck length aspects, as indicated by the results from Group A, may be an alternative when no other options are available or feasible.

Is There a Role for Heli-FX Endoanchors in Treating Type 1B Common Iliac Artery Endoleaks?

OBJECTIVES

The management of type 1B endoleaks following endovascular aortic aneurysm repair (EVAR) can be challenging. The Heli-FX Endoanchor system effectively treats proximal type 1A endoleaks but has not been used for type 1B common iliac artery endoleaks. This study demonstrates that it is both safe and effective in being used in the common iliac artery (CIA) limb of an EVAR.

METHODS

A retrospective review of patients identified through coding and medical records was performed to extract information on demographics, aneurysmal features, operative features, and postoperative outcomes. This was then collated and analysed thoroughly and compared to existing research.

RESULTS

Four patients with six type 1B CIA endoleaks were treated with Heli-FX Endoanchors in the CIA limbs of EVAR grafts. There was 100% technical success rate with complete exclusion of the endoleaks at 6 months. With mean follow up of 714 days, there were no Endoanchor-specific complications. One patient required explantation of the aortic endograft due to contralateral limb fracture, where it was found that an Endoanchor had penetrated the common iliac vein, requiring primary closure.

CONCLUSIONS

Heli-FX Endoanchors were effective within this cohort of patients, though key risks were identified. Adjacent anatomy to the CIA must be considered, which also have nearly half the arterial thickness compared to the aorta. Pre-operative planning is essential given the theoretical risk of placing Endoanchors.

Brazilian Society for Angiology and Vascular Surgery guidelines on abdominal aortic aneurysm

The Brazilian Society of Angiology and Vascular Surgery, through the Guidelines Project, presents new Abdominal Aortic Aneurysm Guidelines, on the subject of care for abdominal aortic aneurysm patients. Its development prioritized descriptive guidelines, using the EMBASE, LILACS, and PubMed databases. References include randomized controlled trials, systematic reviews, meta-analyses, and cohort studies. Quality of evidence was evaluated by a pair of coordinators, aided by the RoB 2 Cochrane tool and the Newcastle Ottawa Scale forms. The subjects include juxtarenal aneurysms, infected aneurysms, and new therapeutic techniques, especially endovascular procedures. The current version of the guidelines include important recommendations for the primary topics involving diagnosis, treatment, and follow-up for abdominal aortic aneurysm patients, providing an objective guide for medical practice, based on scientific evidence and widely available throughout Brazil.

Early Clinical Outcomes of the Active Seal Technology of the AFX Endovascular Aortic Aneurysm System With the VELA Cuff for Patients With a Conical Proximal Neck

PURPOSE

To evaluate the efficacy of the Active Seal technology employed in the AFX endovascular aortic aneurysm system (AFX), during endovascular aneurysm repair (EVAR) in patients with abdominal aortic aneurysms (AAAs) having a conical proximal neck.

MATERIALS AND METHODS

A retrospective analysis of the EVAR for AAA with a conical proximal neck using the AFX was performed at 17 Japanese hospitals between January 2016 and August 2020. The conical proximal neck was defined as a cone-shaped proximal neck, with more than 10% diameter increase within a 15 mm length at the proximal landing zone. All anatomical analyses were performed in the core laboratory, and cases with parallel walls within the proximal neck adequate for the landing zone were excluded from the study.

RESULTS

This study included 53 patients, but only 39 patients (mean age, 76.6 ± 6.7 years; 87.0% males; mean aneurysm diameter, 52.0 ± 8.0 mm) were analyzed after being characterized as having a pure conical neck by the core laboratory. The mean proximal neck diameters at the lower renal artery and proximal edge of the aneurysm were 20.0 ± 2.9 mm and 27.5 ± 4.9 mm, respectively. The mean proximal neck length was 21.5 ± 6.0 mm. Instructions for use violations other than the conical neck were observed in 15 patients (38.5%). The VELA cuff was used in all cases; however, additional proximal cuff was required in 9 more cases (23.1%). The Active Seal technology was able to significantly extend the proximal sealing zone from 21.5 ± 6.0 to 26.0 ± 12.2 mm (p = .047). Thirty-six patients completed the 12-month follow-up (one patient was lost to follow-up, and 2 patients died from causes unrelated to the aneurysm), and there were no type-1a and 3 endoleaks with only one reintervention (2.6%) related to type 1b endoleak in the 12-month period. Furthermore, there was no significant enlargement of the proximal neck diameter at 12 months (at 1 month: 20.6 ± 3.4 mm and at 12 months: 21.3 ± 3.8 mm; p = .420).

CONCLUSION

The Active Seal technology of the AFX significantly extended the proximal seal zone and no type-1a endoleak and proximal neck dilation was observed in patients with conical proximal neck at 12 months.

EndoSuture aneurysm repair versus fenestrated aneurysm repair in patients with short neck abdominal aortic aneurysm

OBJECTIVE

The aim of this study was to compare midterm results of EndoAnchors in EndoSuture aneurysm repair (ESAR) versus fenestrated endovascular aneurysm repair (FEVAR) in short neck abdominal aortic aneurysm (AAA).

METHODS

All patients who underwent an ESAR procedure for a short neck AAA at our center between September 2017 and May 2020 were considered for analysis. To form the control group, preoperative computed tomography angiography of patients who underwent FEVAR for juxtarenal AAA between April 2012 and May 2020 were reviewed and patients who met short neck criteria selected. A propensity-matched score on neck length and neck diameter was calculated, resulting in 18 matched pairs. AAA shrinkage, type Ia endoleaks (EL), AAA-related reinterventions, and AAA-related deaths were compared.

RESULTS

The median AAA diameter was 54 mm (interquartile range [IQR], 52-61 mm) versus 58 mm (IQR, 53-63 mm) with a median neck length of 8 mm (IQR, 6-12 mm) vs 10 mm (IQR, 6-13 mm) in ESAR and FEVAR patients, respectively. Technical success was 100% in both groups. Procedural success was 94% in the ESAR group versus 100% in the FEVAR group. The median procedure duration was 138 mm (IQR, 113-182 mm) vs 240 mm (IQR, 199-293 mm) ( P < .001) and the median length of stay was 2 days (IQR, 2-3 days) vs 7 days (IQR, 6-7 days) (P < .001) in ESAR and FEVAR patients, respectively. No major hospital complications were observed in ESAR patients compared with two in FEVAR patients (11%) with one transient acute kidney injury and one transient paraplegia. The median follow-up was 23 months (IQR, 19-33 months) vs 36 months (IQR, 22-57 months) with 67% versus 61% AAA shrinkage in the ESAR and FEVAR groups, respectively (P = .73). No type Ia EL, proximal neck-related reinterventions, or AAA-related deaths were observed in either group. No AAA-related reintervention was observed in the ESAR group versus three reinterventions in the FEVAR group (P = .23).

CONCLUSIONS

ESAR seems to be a safe technique with no major postoperative complications or reinterventions observed during follow-up. It seems to offer similar midterm results as FEVAR in terms of type Ia EL, aneurysm shrinkage, and aneurysm-related mortality. ESAR seems to be a good off-the-shelf alternative to FEVAR in case of technical constraints.

Mid-term outcomes of the use of endoanchors during thoracic endovascular aortic repair in multicentre analysis

Objective

To describe mid-term outcomes of the use of EndoAnchors as an adjunct for arch and thoracic endovascular aortic repair (TEVAR).

Methods

A retrospective multicentre series from nine centres using the Heli-FX EndoAnchor System (Medtronic Inc, Minneapolis, USA) at TEVAR over May 2014–May 2019 is presented. The study is registered at ClinicalTrials.gov with number NCT04100499. The primary outcome was freedom from Type I endoleak at EndoAnchors deployments; secondary outcomes included evaluation of aortic wall penetration (AWP) at first computed tomography scan, EndoAnchor-related issues and mortality.

Results

54 high-risk patients (35 males/19 females, age 73 ± 11 years) with arch, thoracic and thoracoabdominal aneurysmal disease (3 chronic post-dissection and one patch pseudoaneurysm), with a mean neck length 19.7 ± 6.6 mm that were treated with multiple hybrid and endovascular techniques were included. A total of 329 EndoAnchors were used with a mean of 6.1 ± 2.5 per patient. Overall adequate AWP was 86%, whereas arch (Ishimaru’s zones 0–2) deployments achieved 80.6% when compared to 87.3% in descending thoracic aorta (dTA); although there was no statistical significance. Freedom from type I endoleaks was 88% at 2 year follow-up, due to 4 type IA endoleaks, two of them successfully treated, one with conservative treatment due to complexity of repair and remaining patient died 1 year later due to endograft infection. There were reported five EndoAnchor-related issues; four losses and one renal stent-graft was crushed due to catheter deflection solved with balloon reinflation. None of the losses had clinical significance. Overall mortality is described for 7 (9.5%) patients, one of them aneurysm-related.

Conclusions

The adjunctive use of EndoAnchors in TEVAR and complex TEVAR procedures achieved acceptable outcomes at midterm in a high-risk series with hostile seal zones. Still, they should be still judiciously used as there is lack of data to suggest a more liberal use; therefore, the landing zone should not be compromised in favour of their use.

Favorable Outcomes in Octogenarians With Hostile Neck Undergoing Endovascular Repair Using EndoAnchors

OBJECTIVES

Standard endovascular repair (EVAR) is not suitable in patients with hostile aortic anatomy. Open aneurysm repair (OAR) has been the gold-standard approach in managing these patients. EndoAnchors have been introduced as a technique to make EVAR in patients with short and angulated necks possible. The use of EndoAnchors in managing hostile aneurysms in octogenarians has not been studied before. Thus, the purpose of this study is to evaluate both short and long-term outcomes in octogenarians versus nonoctogenarians patients with hostile aortic anatomy undergoing EVAR using EndoAnchors.

METHODS

Only patients enrolled in the primary arm of the ANCHOR registry were included and stratified into octogenarians (80-89 years) and nonoctogenarians (<80 years). Standard univariate (chi-square, fisher's exact, student's t-tests) and multivariable (logistic, cox-regression) analysis was used to evaluate patients' characteristics and outcomes between octogenarians versus nonoctogenarians as appropriate.

RESULTS

Of 461 patients, 21% (N = 97) were octogenarians. Compared to nonoctogenarians, octogenarians were more likely to have a history of renal (32.0% vs. 18.4%) and genitourinary (30.9% vs. 21.2%) disease (both P < 0.05). They were also more likely to have an AAA diameter greater than 55 mm compared to nonoctogenarians (59% vs. 46%), had increased neck tortuosity index (mean [S.D.] 1.07 [0.08] vs. 1.05 [0.05]), greater proximal neck angulation (mean [S.D.]: 28.2 [17.3] vs. 23.7 [16] degrees) and were more likely to have localized (29.3% vs. 18.7%) and diffuse (25.6% vs. 20.7%) neck calcification (All P < 0.05). The overall procedural success was similar between both groups. However, octogenarians had higher rates of endoleaks at completion (32.0% vs. 21.2%, P = 0.03) and 30-day bleeding (12.4% vs. 5.8%) and cardiac (13.4% vs. 5.2%) complications (All P < 0.05). Additionally, compared to nonoctogenarians, octogenarians had lower freedom from all-cause mortality (87.90% vs. 96.50%) and type II endoleak (73.30% vs. 88.60%) based on Kaplan Meier estimates through one year (Both P < 0.05). In multivariable cox-regression analysis, octogenarians demonstrated a 5-fold increase in all cause mortality (HR [95% CI]: 5.19 [1.92-14], P = 0.001) and a 3-fold increase in type II endoleak (HR [95% CI]: 2.99 [1.54-5.81], P = 0.001) at 1-year. However, no significant difference was seen in aneurysm/device related mortality (HR [95% CI]: 1.42 [0.14-14.7], P = 0.77) and type I endoleak (HR [95% CI]: 1.71 [0.31-9.55], P = 0.54) at 1-year.

CONCLUSIONS

Despite a worse aortic neck anatomy, octogenarians undergoing EVAR using EndoAnchors showed acceptable short and long-term outcomes. The results of our study could expand the utilization of EVAR in octogenarians with hostile neck.

Evolving Concepts, Management, and Treatment of Type 1 Endoleaks after Endovascular Aneurysm Repair

Over the past 20 years, there has been tremendous progress in endovascular aneurysm repair techniques and devices. The application of new third- and fourth-generation devices (from 2003 onward) has led to changes in the incidence and management of endoleaks. This comprehensive review aims to outline the most recent concepts with respect to pathophysiology/risk factors and management of Type 1 endoleaks.

Endograft platform does not influence aortic neck dilatation after infrarenal endovascular aneurysm repair with primary endostapling

OBJECTIVES

Aortic endografts used for endovascular aneurysm repair (EVAR) are based on varying skeletal platforms such as stainless steel or nitinol stents, using radial force applied to seal at the aneurysm neck, and varying proximal fixation methods, applying either suprarenal or infrarenal fixation. This study assesses whether varying skeleton/fixation platforms affect neck-related outcomes after primary endostapling with Heli-FX EndoAnchors at EVAR.

METHODS

Retrospective analysis of a prospective database of infrarenal EVAR undertaken at a single centre. Chimney-EVAR, secondary cases were excluded. Primary outcomes analysed included neck diameter evolution from pre-EVAR to latest imaging follow-up, including a comparison of stent platforms to see if there was any outcome difference between those using stainless steel or nitinol, as also freedom from type I endoleakage and migration. Secondary outcomes assessed included average number of EndoAnchors, and sac size patterns before and after EVAR.

RESULTS

A total of 101 patients underwent endostapled infrarenal EVAR between September 2013 and March 2020. After exclusion of ineligible patients, 84 patients (76 male, 8 female, age 73.7 ± 7.8 years) were available for analysis. 57/27 endografts used suprarenal/infrarenal fixation, whilst 16/68 devices were based on stainless steel/nitinol platforms, respectively. Mean oversizing was higher for stainless steel/suprarenal fixation endografts (p = 0.02). A total of 582 EndoAnchors were deployed, averaging 7 ± 2 per patient. Median neck diameter was 25 mm (IQR 22-31) with 22 necks having non-parallel morphology (conical, tapered or bubble). Median follow-up period was 28.5 (IQR 12-43) months. Neck evolution studies suggested aortic neck dilatation of 5 ± 4 mm (p <0.001, paired T-test), independent of platforms employed (p = NS, ANOVA). There was no endograft migration; one immediate post-EVAR endoleak settled by eight weeks. There was a mean 5.7 ± 8.2 mm sac size reduction (p < 0.001, paired T-test).

CONCLUSION

Aortic neck dilatation occurs after EVAR with primary endostapling, but the process may be independent of stainless steel/nitinol platforms, possibly due to the attenuating effect of EndoAnchors. Adjunct aneurysm neck fixation by primary endostapling prevents migration regardless of whether suprarenal/infrarenal fixation is the primary fixative method. Device platform choice therefore may be left to the operator discretion if primary endostapling is applied at EVAR. Freedom from complications such as migration and endoleakage in the intermediate term suggests a higher level of 'tolerance' to aortic neck dilatation with primary endostapling. We would therefore suggest routine usage of EndoAnchors at EVAR when not otherwise contraindicated.

Outcomes of endosutured aneurysm repair with the Heli-FX EndoAnchor implants

OBJECTIVE

Endovascular aneurysm repair has gained field over open surgery for the treatment of abdominal aortic aneurysm. However, type Ia endoleak represents a common complication especially in hostile neck anatomy that is recently faced using endoanchors. We conducted a systematic review and meta-analysis to collect and analyse all the available comparative evidence on the outcomes of the endosuture aneurysm repair in patients with or without hostile neck in standard endovascular aneurysm repair.

METHODS

The current meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All the prospective and retrospective studies reporting primary use of the Heli-FX EndoAnchor implants were considered eligible for inclusion in this study. The main study outcomes (technical success of endoanchor implantation, incidence of type Ia endoleak, aortic stent graft migration and the percentage of patients who presented regression or expansion of aneurysm sac throughout the follow-up) were subsequently expressed as proportions and 95% confidence intervals.

RESULTS

Eight studies with a total of 968 patients were included in a pooled analysis. The technical success of the primary endoanchor fixation was 97.12% (95%CI: 92.98-99.67). During a mean six months follow-up period, a pooled rate of 6.23% (95%CI: 0.83-15.25) of the patients developed a persistent type Ia endoleak despite the primary implantation. Migration of the main graft was reported in five studies, in which a 0.26% (95%CI = 0.00-1.54) of the patients required an additional proximal aortic cuff. Regression of the aneurysm sac was observed at 68.82% (95%CI: 51.02-84.21). An expansion of the aneurysm sac was found in 1.93% (95%CI: 0.91-3.24) of the participants. The overall survival rate was 93.43% (95%CI: 89.97-96.29) at a mean six months follow-up period.

CONCLUSIONS

Endosuture aneurysm repair with the Heli-FX EndoAnchor implants seems to be technically feasible and safe either for prevention or for repair of intraoperative type Ia endoleak. Despite the primary implants of endoanchors, few cases of persistent type Ia endoleak and migration are still conspicuous. Long-term follow up is needed to determinate the role of this therapeutic option in the treatment of aortic aneurysms.

Adjunctive Procedures for Challenging Endovascular Abdominal Aortic Repair: When Needed and How Effective?

Endovascular aneurysm repair (EVAR) is now considered the first choice treatment modality for abdominal aortic aneurysm (AAA) treatment. Advocates for endovascular strategies will try to treat all AAA by EVAR, regardless if the anatomy is conducive for treatment or not. However, the long-term outcomes of EVAR outside the instructions for use (IFU) due to a hostile aneurysmal neck or iliac artery anatomy are known to be poor. The EVAR procedures can be classified according to the technical difficulty, IFU, and need for visceral revascularization: standard, adjunctive, and complex EVAR. The situation required for adjunctive procedures can be classified as the following four steps: a hostile neck (i.e., short or severely angled); large inferior mesenteric or lumbar artery; tough iliac artery anatomy, such as a short common iliac artery and stenotic external iliac artery; and limitations in vascular access. This article will discuss the adjunctive procedures to overcome hostile aneurysm neck and unsuitable iliac artery anatomy.

Evolving concepts and management of endoleaks after endovascular aneurysm repair: where do we stand in 2019?

In recent years, there has been tremendous progress in endovascular aneurysm repair (EVAR) techniques and devices. This process has seen a change in incidence, risk factors, and treatment of endoleaks as well as in follow-up protocols after EVAR. In particular, recent literature has highlighted new concepts in the evaluation and prevention/treatment of type I and II endoleak after standard EVAR. There is also recent evidence regarding new imaging protocols for follow-up after EVAR, which include magnetic resonance imaging and contrast-enhanced ultrasound. This comprehensive review aims to outline the most recent concepts on imaging follow-up, pathophysiology/risk factors, and management of endoleaks.

g. Scholten G, Kuipers H, Slump CH, de Vries JPPM. Effect of Different EndoAnchor Configurations on Aortic Endograft Displacement Resistance: An Experimental Study

Purpose: This study investigated the effect of different EndoAnchor configurations on aortic endograft displacement resistance in an in vitro model. Materials and Methods: An in vitro model was developed and validated to perform displacement force measurements on different EndoAnchor configurations within an endograft and silicone tube. Five EndoAnchor configurations were created: (1) 6 circumferentially deployed EndoAnchors, (2) 5 EndoAnchors within 120° of the circumference and 1 additional, contralateral EndoAnchor, (3) 4 circumferentially deployed EndoAnchors, (4) 2 rows of 4 circumferentially deployed EndoAnchors, and (5) a configuration of 2 columns of 3 EndoAnchors. An experienced vascular surgeon deployed EndoAnchors under C-arm guidance at the proximal sealing zone of the endograft. A constant force with increments of 1 newton (N) was applied to the distal end of the endograft. The force necessary to displace a part of the endograft by 3 mm was defined as the endograft displacement force (EDF). Two video cameras recorded the measurements. Videos were examined to determine the exact moment 3-mm migration had occurred at part of the endograft. Five measurements were performed after each deployed EndoAnchor for each configuration. Measurements are given as the median and interquartile range (IQR) Q1, Q3. Results: Baseline displacement force measurement of the endograft without EndoAnchors resulted in a median EDF of 5.1 N (IQR 4.8, 5.2). The circumferential distribution of 6 EndoAnchors resulted in a median EDF of 53.7 N (IQR 49.0, 59.0), whereas configurations 2 through 5 demonstrated substantially lower EDFs of 29.0 N (IQR 28.5, 30.1), 24.6 N (IQR 21.9, 27.2), 36.7 N, and 9.6 N (IQR 9.4, 10.0), respectively. Decreasing the distance between the EndoAnchors over the circumference of the endograft increased the displacement resistance. Conclusion: This in vitro study demonstrates the influence EndoAnchor configurations have on the displacement resistance of an aortic endograft. Parts of the endograft where no EndoAnchor has been deployed remain sensitive to migration. In the current model, the only configuration that rivaled a hand-sewn anastomosis was the one with 6 EndoAnchors. A circumferential distribution of EndoAnchors with small distances between EndoAnchors should be pursued, if possible. This study provides a quantification of different EndoAnchor configurations that clinicians may have to adopt in clinical practice, which can help them make a measured decision on where to deploy EndoAnchors to ensure good endograft fixation.

The use of EndoAnchors in endovascular repair of abdominal aortic aneurysms with challenging proximal neck: Single-centre experience

Objectives

The aim of this study was to present a single-centre experience with EndoAnchors in patients who underwent endovascular repair for abdominal aortic aneurysms with challenging proximal neck, both in the prevention and treatment of endograft migration and type Ia endoleaks.

Methods

We retrospectively analysed 17 consecutive patients treated with EndoAnchors between June 2015 and May 2018 at our institution. EndoAnchors were applied during the initial endovascular aneurysm repair procedure (primary implant) to prevent proximal neck complications in difficult anatomies (nine patients), and in the follow-up after aneurysm exclusion (secondary implant) to correct type Ia endoleak and/or stent-graft migration (eight patients).

Results

Mean time for anchors implant was 23 min (range 12–41), with a mean of 5 EndoAnchors deployed per patient. Six patients in the secondary implant group required a proximal cuff due to stent-graft migration ≥10 mm. Technical success was achieved in all cases, with no complications related to deployment of the anchors. At a median follow-up of 13 months (range 4–39, interquartile range 9–20), there were no aneurysm-related deaths or aneurysm ruptures, and all patients were free from reinterventions. CT-scan surveillance showed no evidence of type Ia endoleak, anchors dislodgement or stent-graft migration, with a mean reduction of aneurysm diameter of 0.4 mm (range 0–19); there was no sac growth or aortic neck enlargement in any case.

Conclusions

EndoAnchors can be safely used in the prevention and treatment of type Ia endoleaks in patients with challenging aortic necks, with good results in terms of sac exclusion and diameter reduction in the mid-term follow-up.

Multicenter Registry about the Use of EndoAnchors in the Endovascular Repair of Abdominal Aortic Aneurysms with Hostile Neck Showed Successful but Delayed Endograft Sealing within Intraoperative Type Ia Endoleak Cases

BACKGROUND

The durability of endovascular aortic aneurysms repair (EVAR) is highly related to several anatomical constraints. The term "hostile neck" describes several anatomical features that usually make EVAR treatment technically demanding despite having higher risk of failure. The aim of the study was to describe a multicenter experience with EVAR and an adjunctive use of EndoAnchors in hostile neck anatomies.

METHODS

Data were prospectively collected from 4 academic vascular centers including 46 patients with a hostile neck treated by standard EVAR with the adjunctive use of EndoAnchors. Twenty-two of them (47.8%, group A) had an intraoperative type Ia endoleak, and 24 (52.2%) patients were treated in a preventive manner (group B). Primary endpoints were technical and procedural success. Secondary endpoints were regression of the aneurysm sac, freedom from type Ia endoleak, and reinterventions.

RESULTS

Neck length and diameter showed no statistical difference in preoperative measures, 9.1 ± 6.9 mm and 8.6 ± 2.8 mm and 25.4 ± 4.7 mm and 27.3 ± 4.7 mm, in group A and B, respectively. Aneurysm sac diameter decreased from 58.2 ± 8 mm and 57.9 ± 9.8 mm to 55.7 ± 8.5 mm and 53.8 ± 10.4 mm in group A and B; respectively, at the last computed tomography scan. Technical and procedural success was 97.8% and 100%, respectively, for group B. Group A showed persistence of type Ia endoleak at completion angiogram in 9 (40.9%) patients. Five of them showed early spontaneous sealing at the first (30 days) computed tomography angiography (CTA), and in the remaining 4, a delayed spontaneous sealing was diagnosed at 12-month CTA. No neck-related secondary procedures were performed. Overall survival was 91%.

CONCLUSIONS

Our study shows that additional use of EndoAnchors can successfully improve the sealing of abdominal endografts in case of intraoperative type Ia endoleaks in hostile neck anatomies, representing a safe and effective endovascular alternative in our armamentarium. However, meticulous radiological follow-up is necessary because complete resolution of all observed intraoperative type Ia endoleaks was not observed until the 12-month CTA follow-up.

Safety of EndoAnchors in real-world use: A report from the Manufacturer and User Facility Device Experience database

Objectives

A hostile proximal neck anatomy is the most common cause of abdominal aorta endovascular aneurysm repair failure leading to a higher risk of device migration, proximal type I endoleak, and subsequent open surgical repair. Endostapling is a technique to attain better fixation of the endograft to the aortic wall, and the only available device in the USA is Aptus Heli-FX EndoAnchor system (Medtronic Vascular, Santa Rosa, CA, USA). Preliminary data have shown efficacy and safety of its use, and the aim of this study is to assess device-related adverse events in real-world clinical use.

Methods

We quarried data from the publicly available Manufacturer and User Facility Device Experience database to identify Aptus Heli-FX EndoAnchor system-related adverse reports in endovascular aneurysm repair since FDA approval till August 31, 2017. An estimate of total devices implanted in the United States was quoted around 7,000 (Medtronic marketing internal data).

Results

Our query identified 229 separate reports, of which there were 85 adverse events (1.2% of the estimated EndoAnchor systems used). The most common adverse events were device dislodgement/fracture (65) and applicator malfunction (20).

Conclusion

In early post-FDA approval use in a real-world setting, the EndoAnchor system is associated with a low rate of adverse events. Device dislodgement and embolization remain the most common adverse events. With increasing use of these devices in more difficult anatomy, careful patient selection and careful attention to technique may help to reduce these events even further.

Sustainability of Individual EndoAnchor Implants in Therapeutic Use to Treat Type Ia Endoleak After Endovascular Aneurysm Repair

Purpose: To investigate changes in penetration depths and angles of EndoAnchor implants with initially good penetration after therapeutic use in endovascular aneurysm repair. Materials and Methods: Patients were selected from the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR; ClinicalTrials.gov identifier NCT01534819). Inclusion criteria were (1) EndoAnchor implantation to treat intraoperative or late type Ia endoleak and (2) at least 2 postoperative computed tomography angiography (CTA) scans. Exclusion criteria were the use of adjunct procedures. Based on these criteria, 54 patients (44 men) with 360 EndoAnchor implants were eligible for this analysis. Penetration depth of each EndoAnchor implant into the aortic wall was judged as (1) good (≥2-mm penetration), (2) borderline (<2 mm or when there was a gap between the endograft and the aortic wall), or (3) no penetration. The penetration depth and longitudinal angles of EndoAnchors with good penetration were investigated on the last available postprocedure CTA scan. Endoleaks were also analyzed. Results: EndoAnchor penetration on the first postprocedure CTA scan was good in 187 (51.9%), borderline in 69 (19.2%), and missing in 104 (28.9%). On the last CTA scan, 182 (97.4%) of the 187 initially well-positioned EndoAnchors remained good. Five (2.6%) EndoAnchors in 4 patients changed configuration over time (4 became borderline and 1 became nonpenetrating), all without any clinical sequelae. The median orthogonal angles of the EndoAnchor implants with good penetration on the first and last CTA scans were 92° [interquartile range (IQR) 85, 98] and 90° (IQR 84, 97), respectively (p=0.822); for longitudinal angles, medians of 85° (IQR 71, 96) and 84° (IQR 70, 96) were found (p=0.043). Of the 18 (33%) patients who had a type Ia endoleak on the first postprocedure CTA, 6 resolved over time. Median follow-up was 13 months, during which no new type Ia endoleak was found. Conclusion: Despite the small number of EndoAnchors analyzed, this study showed that the sustainability of EndoAnchor implants with initially good penetration is satisfactory at 1-year follow-up. The vast majority of EndoAnchor implants with good penetration initially remained in good position; <3% of implants became borderline or nonpenetrating, without any clinical consequence.

Midterm Single-Center Results of Endovascular Aneurysm Repair With Additional EndoAnchors

PURPOSE

To review midterm clinical outcomes of EndoAnchor placement during or after endovascular aneurysm repair (EVAR) or chimney EVAR (ch-EVAR).

MATERIALS AND METHODS

A retrospective analysis was conducted of 51 consecutive patients [median age 75 years; 38 men] who underwent EVAR/ch-EVAR with EndoAnchor placement between June 2010 and December 2016 to prevent seal failures (31, 61%) or to treat type Ia endoleak and/or migration (20, 39%). Median aortic neck diameter was 27.7 mm and median neck length was 9.0 mm. Thirty-three (65%) had a conical neck; 48 (94%) had at least 1 hostile neck characteristic. Thirty-two (63%) patients had severe comorbidities (ASA score ⩾III). Eight patients had a single ch-EVAR procedure. Baseline patient characteristics, anatomic variables, procedure details, early and late complications, reinterventions, and aneurysm-related and all-cause mortality rates were recorded. Follow-up imaging was performed with computed tomography angiography (CTA) or duplex ultrasonography.

RESULTS

Median procedure time was 100 minutes; a median of 6 EndoAnchors were implanted. There were 10 (10%) residual type Ia endoleaks at the end of the procedure; 9 had resolved by the first postoperative CTA. One residual and 2 new type Ia endoleaks were identified at the first postoperative imaging. Median follow-up for the entire cohort was 24.0 months, during which 3 new type Ia endoleaks were identified. Five of the 6 type Ia endoleaks were treated, 1 resolved spontaneously. There was 1 endograft limb occlusion without clinical consequences, 1 chimney graft occlusion without possibilities for a reintervention, 1 rupture after type IV endoleak (a Nellix device was successfully deployed within the main device), and 1 complete graft explantation for infection. There was no new-onset hemodialysis. Kaplan-Meier estimates of freedom from type Ia endoleak, proximal neck-related reinterventions, and aneurysm-related mortality at 2 years were 87.3%, 92.2%, and 94.0%, respectively.

CONCLUSION

EndoAnchors are helpful in the endovascular treatment of unfavorable proximal aortic necks, with fair midterm results.

Type IIIb Endoleak and Relining

Purpose: To examine the changes in distraction force following relining of a conventional abdominal aortic stent-graft with a type IIIb endoleak using the Nellix endovascular sealing device compared to a unilateral stent-graft. Methods: Relining is often used to repair type IIIb endoleaks, but the consequences to graft stability are unknown. A mathematical model was constructed based on pressure and volume flow through the stent-grafts, incorporating recognized distraction force equations. Steady flow was presumed at peak systolic pressures to calculate the maximum distraction force, with gravity ignored. Distraction forces for 28- to 36-mm-diameter stent-graft bodies with 16-mm limbs were calculated and compared to forces following relining with single and double Nellix devices or the Renu unilateral device. Results: Distraction forces for the 28-, 32-, and 36-mm stent-grafts prior to relining were 5.99, 10.21, and 14.99 N, respectively. Similar forces were reported after relining with bilateral Nellix devices (5.86, 10.08, and 14.86 N, respectively). However, use of a unilateral Nellix increased the distraction forces to 9.92, 14.14, and 18.92 N, respectively. These were comparable to the increase observed after relining with a Renu unilateral stent-graft (9.87, 14.09, and 18.86 N, respectively). The proportional increase in distraction force for a unilateral relining ranged from 26% to 66%, with the greatest increase noted in the smaller diameter main bodies. Conclusion: Relining a stent-graft with a type IIIb endoleak using bilateral Nellix devices does not increase the distraction force. However, a unilateral Nellix device or the Renu system could theoretically increase the distraction force by up to 66%, potentially risking migration and type Ia endoleak. In clinical practice, these results suggest that a relining with bilateral Nellix may have benefits over the Renu unilateral stent-graft.

Aortic Neck Anatomic Features and Predictors of Outcomes in Endovascular Repair of Abdominal Aortic Aneurysms Following vs Not Following Instructions for Use

BACKGROUND

A significant number of patients undergo endovascular repair of abdominal aortic aneurysms (EVAR) outside the instructions for use (IFU). This study will examine various aortic neck features and their predictors of clinical outcomes.

STUDY DESIGN

We performed a retrospective analysis of prospectively collected data on EVAR patients. Neck features outside IFU were analyzed. Kaplan-Meier and multivariate analyses were used to predict their effect as single features, or in combination, on outcomes.

RESULTS

Fifty-two percent of 526 patients had 1 or more features outside the IFU. The overall technical success rate was 99%, and perioperative complication rates were 7% and 12% for IFU vs outside IFU use, respectively (p = 0.04). Type I early endoleak and early intervention rates were 7% and 10% for IFU vs 18% and 24% for outside IFU (p = 0.0002 and p < 0.0001). At a mean follow-up of 30 months, freedom from late type I endoleak and late reintervention at 1, 2, and 3 years for IFU were 99.5%, 99.5%, and 98.4%, and 99.4%, 98%, and 96.8%; vs 98.9%, 98.1%, and 98.1%, and 97.5%, 96.2%, and 95.2% for outside IFU (p = 0.049 and 0.799), respectively. Survival rates at 1, 2, and 3 years for IFU were 97%, 93.5%, and 89.8%; vs 93.7%, 88.8%, and 86.3% for outside IFU (p = 0.035). Multivariate analysis showed that a neck angle > 60 degrees had odds ratios for death, sac expansion, and early intervention of 6, 2.6, and 3.3, respectively; neck length < 10 mm had odds ratios of 2.8 for deaths, 3.4 for early intervention, 4.6 for late reintervention, and 4.3 for late type I endoleak.

CONCLUSIONS

Patients with neck features outside IFU can be treated with EVAR; however, they have higher rates of early and late type I endoleak, early intervention, and late death.