Improved Midterm Outcomes Using Standard Devices and EndoAnchors for Endovascular Repair of Abdominal Aortic Aneurysms with Hyperangulated Necks

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.

Selective aneurysmal sac neck-targeted embolization during endovascular repair of abdominal aortic aneurysm with hostile neck anatomy

PURPOSE

To evaluate the efficacy and safety of selective aneurysmal sac neck-targeted embolization in endovascular aneurysm repair (EVAR) in patients with a hostile neck anatomy (HNA).

MATERIALS AND METHODS

Between October 2020 and June 2022, patients with an abdominal aortic aneurysm (AAA) and HNA who underwent EVAR with a low-profile stent graft and a selective aneurysmal sac neck-targeted embolization technique were analysed. An HNA was defined by the presence of any of the following parameters: infrarenal neck angulation > 60°; neck length < 15 mm; conical neck; circumferential calcification ≥ 50%; or thrombus ≥ 50%. Before occluding the entire aneurysm during the procedure, a buddy wire was loaded prophylactically into the sac through the contralateral limb side. If a type Ia endoleak (ELIa) occurred and persisted despite adjunctive treatment such as balloon moulding or cuff extension, this preloaded wire could be utilized to enable a catheter to reach the space between the stent graft and sac neck to perform coil embolization. In the absence of ELIa, the wire was simply retracted. The primary outcome of this study was freedom from sac expansion and endoleak-related reintervention during the follow-up period; secondary outcomes included technical success and intraoperative and in-hospital postoperative complications.

RESULTS

Among the 28 patients with a hostile neck morphology, 11 (39.5%) who presented with ELIa underwent intraprocedural treatment involving sac neck-targeted detachable coil embolization. Seventeen individuals (60.7%) of the total patient population did not undergo coiling. All patients in the coiling group underwent balloon moulding, and 2 patients additionally underwent cuff extension. In the noncoiling group, 14 individuals underwent balloon moulding as a treatment for ELIa, while 3 patients did not exhibit ELIa during the procedure. The coiling group showed longer operating durations (81.27 ± 11.61 vs. 70.71 ± 7.17 min, P < 0.01) and greater contrast utilization than the noncoiling group (177.45 ± 52.41 vs. 108.24 ± 17.49 ml, P < 0.01). In the entire cohort, the technical success rate was 100%, and there were no procedure-related complications. At a mean follow-up of 18.6 ± 5.2 months (range 12-31), there were no cases of sac expansion (19 cases of sac regression, 67.86%; 9 cases of stability, 32.14%) or endoleak-related reintervention.

CONCLUSIONS

Selective aneurysmal sac neck-targeted embolization for the treatment of ELIa in AAA patients with an HNA undergoing EVAR is safe and may prevent type Ia endoleak and related sac expansion after EVAR.

Endovascular management of aortic aneurysm with severe neck angulation and/or iliac artery tortuosity using multiple stiff wire technique: a case series

Background

Suitable aortic neck is one of the essential components for thoracic endovascular aortic repair (TEVAR) and endovascular aortic repair (EVAR). Advanced techniques were developed to adjust and compromise the aneurysm neck angulation but with adding additional devices and complexity to the procedure. We proposed a simple technique to modify severe neck angulation and/or iliac artery tortuosity by using the multiple stiff wire (MSW) technique.

Method

Two femoral accesses were required for the MSW technique. A guidewire with a support catheter was inserted through the right and left femoral arteries and positioned in the abdominal or thoracic aorta. Wire exchanges were done with extra stiff wire in both femoral accesses. It can be considered to add multiple stiff wires to align the torturous neck / iliac artery. Delivery of the stent graft main body can be done via one of the accesses.

Result

Six patients with different aortic pathology were admitted to our hospital. Four patients undergo EVAR procedure and two patients undergo TEVAR procedure. All patients had aortic neck angulation problems with one patient having iliac artery tortuosity. MSW technique was performed on the patients with good results. Follow-up CTA after 3 months revealed a good stent position without stent migration and no endoleak was found in all but one patient.

Conclusion

MSW technique is a simple and effective technique to modify aortic neck/iliac artery angulation in TEVAR or EVAR procedure.

A meta-analysis of safety and efficacy of endovascular aneurysm repair in aneurysm patients with severe angulated infrarenal neck

Objectives

A growing number of abdominal aortic aneurysms with severe angulated neck anatomy is treated by endovascular means. However, contradictory early and late outcomes have been reported. Our review and outcome analysis attempted to evaluate the available literature and provide clinicians with a base for clinical implementation and future research.

Materials and methods

A systematic review of the literature was undertaken to identify the outcomes of endovascular aneurysm repair in patients with severe infrarenal neck angulation (SNA ≥ 60°) vs non-severe neck angulation (NSNA). Outcome measures included perioperative complications, type 1a endoleak, neck-related secondary procedures, stent graft migration, aneurysm rupture, increase (>5mm) in sac diameter, all-cause and aneurysm-related mortality (PROSPERO Nr.: CRD42021233253).

Results

Six observational studies reporting on 5981 patients (1457 with SNA and 4524 with NSNA) with a weighted mean follow-up period of 1.8 years were included. EVAR in SNA compared with NSNA was associated with a higher rate of type 1a endoleak at 30 days (4.0% vs 1.8%; p< 0.00001), at 1 year (2.8% vs 1.9%; p<0.03), at 2 years (4.9% vs 2.1%; p< 0.0002), at 3 years (5.6% vs 2.6%; p< 0.0001). The rate of neck-related secondary procedures was significantly higher at 1 year (6.6% vs 3.9%; p<0.05) and at 3 years (13.1% vs 9%; p<0.05). Graft migration, aneurysm sack increase, aneurysm rupture and all-cause mortality were not statistically different at mid-term.

Conclusions

The use of EVAR in severely angulated infrarenal aortic necks is associated with a high rate of early and mid-term complications. However, aortic related and all-causes mortality are not higher compared to patients with NSNA. Therefore, EVAR should be cautiously used in patients with SNA.

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.

Endovascular aortic repair with EndoAnchors demonstrate good mid-term outcomes in physician-initiated multicenter analysis-The PERU registry

OBJECTIVES

We aim to describe real-world outcomes from multicenter data about the efficacy of adjunct Heli-FX EndoAnchor usage in preventing or repairing failures during infrarenal endovascular aneurysm repair (EVAR), so-called EndoSutured-aneurysm-repair (ESAR).

METHODS

The current study has been assigned an identifier (NCT04100499) at the US National Library of Medicine (https://ClinicalTrials.gov). It is an observational retrospective study of prospectively collected data from seven vascular surgery departments between June 2010 and December 2019. Patients included in the ANCHOR registry were excluded from this analysis. The decision for the use of EndoAnchors was made by the treating surgeon or multidisciplinary aortic committee according to each center's practice. Follow-up imaging was scheduled according to each center's protocol, which necessarily included either abdominal ultrasound or radiography or computed tomographic scan imaging. The main outcomes analyzed were technical success, freedom from type Ia endoleaks (IaEL), all-cause and aneurysm-related mortality, and sac variation and trends evaluated for those with at least six months imaging follow-up.

RESULTS

Two hundred and seventy-five patients underwent ESAR in participating centers during the study period. After exclusions, 221 patients (184 males, 37 females, mean age 75 ± 8.3 years) were finally included for analysis. Median follow-up for the cohort was 27 (interquartile range 12-48) months. A median 6 (interquartile range 3) EndoAnchors were deployed at ESAR, 175 (79%) procedures were primary and 46 (21%) revision cases, 40 associated with type IaEL. Technical success at operation (initial), 30-day, and overall success were 89, 95.5, and 96.8%, respectively; the 30-day success was higher due to those with subsequent spontaneous proximal endoleak seal. At two years, freedom from type IaEL was 94% for the whole series; 96% and 86% for the primary and revision groups, respectively; whereas freedom from all-cause mortality, aneurysm-related mortality, and reintervention was 89%, 98%, and 87%, respectively. Sac evolution pre-ESAR was 66 ± 15.1 vs. post ESAR 61 ± 17.5 (p < 0.001) and for 180 patients with at least six-month follow-up, 92.2% of them being in a stable (51%) or regression (41%) situation.

CONCLUSIONS

This real-world registry demonstrates that adjunct EndoAnchor usage at EVAR achieves high rates of freedom from type IaEL at mid-term including in a high number of patients with hostile neck anatomy, with positive trends in sac-size evolution. Further data with longer follow-up may help to establish EndoAnchor usage as a routine adjunct to EVAR, especially in hostile necks.

Estimating the "Pull" on a Pullthrough Wire: A Pilot Study

Objective

Pullthrough/body floss wires are used to track endovascular devices across tortuous aorto-iliac anatomy encountered during endovascular repair of abdominal or thoracic aortic aneurysms. The tension imparted on such wires is arbitrary and has never been quantified. This pilot study attempted to quantify the tension used to stiffen the floppy hydrophilic wires typically used in such a scenario.

Methods

Two linked experiments were undertaken, the first by tasking 13 blinded vascular surgeons (eight male, five female; mean age 36 ± 11 years, including nine trainees) with pulling a long floppy hydrophilic wire (Radifocus Guidewire M Stiff, Terumo UK, Bagshot, Surrey, UK) attached at the other end to a horizontally configured industrial scale (HDN-N Hanging Scale, Kern & Sohn GmbH, Balingen, Germany), to simulate what they individually felt was an “appropriate” tension; the second by using the derived average tensioning force to set up a pullthrough wire within a rigid life like aorto-iliac model to assess whether a test device (16F Sentrant Introducer Sheath, Medtronic Limited, Watford, UK) could be delivered over such a tensioned wire in both brachiofemoral and femorofemoral configurations.

Results

The mean tension exerted by the group on the wire was 38.3 ± 14.8 N (equivalent to 3.9 kgf). Pullthrough wire tensioning was undertaken by fixing one end and applying a 3.9 kg weight at the other. The test device was successfully deployed into the infrarenal aortic position and also across the aortic bifurcation, via brachiofemoral and femorofemoral pullthrough configurations, respectively.

Conclusion

Successful test device deliveries suggest that a minimum tension equivalent to almost 4 kgf applied to a floppy wire can provide “stiffeningˮ to allow device tracking across tortuous aorto-iliac anatomy. More studies are needed to ascertain whether lower tensions can be applied; these results may help provide a platform for other such studies depending on configuration, aortic geometry, and device or wire/tension characteristics.

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Pullthrough wires are used at EVAR/TEVAR when tortuous anatomy is encountered

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The tension on such pullthrough wires has not been quantified

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Typically floppy hydrophilic wires are used to traverse such tortuous anatomy

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Floppy wires become the functional equivalent of stiff wires when tensioned

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This study for the first time quantifies the tension forces on pullthrough wires

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.

The Impact of EndoAnchor Penetration on Endograft Structure: First Report of Explant Analysis

Objective

The adjunctive use of Heli-FX EndoAnchors (EAs) in endovascular aneurysm repair has been proposed for the treatment or prevention of type Ia endoleaks. The aim of this study was to evaluate the impact of the penetration of EAs on endograft textile structure from two aortic endografts that had been explanted for persistent type Ia endoleak despite the implantation of EAs.

Methods

An Aorfix aortic endograft was implanted in an 85 year old man. Six months later, six EAs were implanted for Ia endoleak. The endograft was explanted as an emergency seven months later for aneurysm rupture. An Endurant II aortic endograft was implanted in an 80 year old man. Seven EAs were implanted 24 months later for type Ia endoleak. A proximal cuff extension with bilateral renal and superior mesenteric artery chimneys was performed 18 months later to treat a persistent type Ia endoleak. Endograft explantation was performed six months later owing to persistent type Ia endoleak and aneurysm sac enlargement. Explant analysis in both cases was performed at GEPROVAS.

Results

Systematic analysis of both explants, including the 13 EAs, revealed the following lesions: (1) alteration of textile structure directly linked to several penetrations of the fabric with the same EA and tears of the textile fibres in two cases; (2) tears of the binding threads as the EA had passed through them in five cases; and (3) interactions between EA and endograft stents in four cases.

Conclusion

The site of EA penetration into the endograft might contribute to endograft fabric damage and to a loss of stability of the endograft at the level of the aortic neck.

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The impact of endoanchors penetration on endograft textile structure has been studied.

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Systematic analysis of two aortic explanted endografts was performed.

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Textile alteration, tears of the binding threads and stents lesions were observed.

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Site of penetration of endoanchors might contribute to endograft fabric damage.

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Follow-up on new technologies through explant analysis programs is mandatory.