First case of relining an aortic bifurcated bypass graft with the Altura endograft to treat anastomotic aneurysms

OBJECTIVE

Use of classic bifurcated endografts for relining of bifurcated aortic bypass grafts with aneurysms is usually precluded by the short distance between the lowermost renal artery and the aneurysmatic bifurcation, rendering their management challenging.

METHODS

We present the use of the Altura endograft in a case of a 75-year old male with large anastomotic aneurysms in the proximal and the left iliac amastomosis of a bifurcated aortic bypass graft. The Altura endograft consists of two separate components with a proximal D-shaped design. Its braided nitinol endoskeleton is attached only at the proximal and distal ends of the inner surface of the polyester fabric and results in adjustable lengths of the components according to the vessel diameters where they are deployed.

RESULTS

A 24 mm Altura sealed successfully at the native infarenal aortic segment covering the entire distance between the lowermost renal artery and the upper end of external iliac artery, providing successful exclusion of the aneurysms. No iliac extensions were used. The completion angiography showed no endoleaks.

CONCLUSIONS

The unique design of Altura makes it ideal for treatment of anastomotic aneurysms of bifurcated bypass grafts, overcoming anatomic limitations. To the best of our knowledge, this is the first report addressing this crucial issue.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Endovascular Repair of a Failed Nellix Endograft Proximal Sealing Zone Using the Altura Stent-Graft: A Case Report and Literature Review

Endovascular aortic aneurysm sealing (EVAS) with the Nellix endograft was initially considered a groundbreaking and acceptable alternative to conventional endovascular aortic aneurysm repair, with encouraging initial results. However, long-term follow-up has revealed a high incidence of endograft-related complications, such as caudal migration and type Ia endoleaks, indicating the need for reintervention. Managing failed EVAS remains challenging and is an ongoing topic of discussion, especially for high-risk patients. We describe a 70-year-old female who initially underwent EVAS with a Nellix endograft and presented after 5 years of follow-up with caudal endograft migration and a type Ia endoleak. The patient was treated with endovascular implantation of an Altura stent-graft, a relatively new low-profile device with a similar double stent configuration. Device migration and endoleaks were undetectable at 12 months of follow-up, suggesting that the Altura might offer a safe and efficient approach in cases of Nellix proximal failure.

Stent-Graft Fabrics Incorporating a Specific Corona Ready to Fenestrate

In situ fenestration of endovascular stent-grafts has become a mainstream bailout technique to treat complex emergent aneurysms while maintaining native anatomical visceral and aortic arch blood supplies. Fabric tearing from creating the in situ fenestration using balloon angioplasty may extend beyond the intended diameter over time. Further tearing may result from the physiologic pulsatile motion at the branching site. A resultant endoleak at the fenestrated sites in stent-grafts could ultimately lead to re-pressurization of the aortic sac and, eventually, rupture. In an attempt to address this challenge, plain woven fabrics were designed. They hold a specific corona surrounding a square-shaped cluster with a plain weave fabric structure, a 2/2 twill, or a honeycomb. The corona was designed to stop potential further tearing of the fabric caused by the initial balloon angioplasty and stent or later post-implantation motion. The cluster within the corona was designed with relatively loose fabric structures (plain weave, 2/2 twill weave, and honeycomb) to facilitate the laser fenestration. Two commercial devices, Anaconda (Vascutek, Terumo Aortic) and Zenith TX2 (Cook), were selected as controls for comparison against this new design. All the specimens were characterized by morphology, thickness, and water permeability. The results demonstrated that all specimens with a low thickness and water permeability satisfied the requirements for a stent graft material that would be low profile and resistant to endoleaks. The in situ fenestrations were performed on all fabrics utilizing an Excimer laser followed by balloon angioplasty. The fabrics were further observed by light microscopy and scanning electron microscopy. The dimension of the fenestrated apertures was smaller than the balloon's diameter. The tearing was effectively confined within the corona. The clinical acceptability of this concept deserves additional bench testing and animal experimentation.

Selection of Bifurcated Grafts' Dimensions during Aorto-Iliac Vascular Reconstruction Based on Their Hemodynamic Performance

During the vascular surgical reconstruction of aorto-iliac occlusive/aneurysmal disease, bifurcated grafts are used where vascular surgeons intra-operatively select the size and the relative lengths of the parent and daughter portions of the graft. Currently, clinical practice regarding the selection of the most favorable geometric configuration of the graft is an understudied research subject: decisions are solely based on the clinical experience of the operating surgeon. This manuscript aims to evaluate the hemodynamic performance of various diameters, D, of bifurcated aortic grafts and relate those with proximal/distal part length ratios (the angle φ between the limbs is used as a surrogate marker of the main body-to-limb length ratio) in order to provide insights regarding the effects of different geometries on the hemodynamic environment. To this end, a computationally intensive set of simulations is conducted, and the resulting data are analyzed with modern statistical regression tools. A negative curvilinear relationship of TAWSS with both φ and D is recorded. It is shown that the angle between limbs is a more important predictor for the variability of TAWSS, while the graft's diameter is an important determinant for the variability of OSI. Large percentages of the total graft area with TAWSS < 0.4 Pa, which correspond to thrombogenic stimulating environments, are only observed for large values of φ and D > 20 mm. This variable ranges from 10% (for the smallest values of φ and D) to 55% (for the largest φ and D values). Our findings suggest that grafts with the smallest possible angle between the limbs (i.e., smallest parent-to-daughter length ratio) present the most favorable hemodynamic performance, yielding the smallest percentage of total graft area under thrombogenic simulating environments. Similarly, grafts with the smallest acceptable diameter should be preferred for the same reason. Especially, grafts with diameters greater than 20 mm should be avoided, given the abrupt increase in estimated thrombogenic areas.

Low-Profile Altura Endograft System for Endovascular Abdominal Aorta Aneurysm Repair. Preliminary Results in Elective and Emergent Situations

BACKGROUND

The objective of this study was to assess the Altura endoprosthesis outcomes up to 12 months for patients affected by infrarenal abdominal aortic aneurysms (AAA) either in elective or emergent situations.

METHODS

This was a single-center retrospective study identifying all patients undergoing endovascular aneurysm repair (EVAR) with the Altura endoprosthesis from January 2021 to August 2022. Outcomes evaluated included mortality, technical and clinical success (freedom from procedure-related death, endoleak, migration, thrombosis, and reintervention), and the freedom from reintervention rate.

RESULTS

A total of 34 (25 elective and 8 emergent) patients who underwent AAA with Altura endoprosthesis were retrospectively reviewed. The technical success of the Altura endograft either in elective or emergent situations was 100%. There was no inhospital mortality, but 1 (3%) patient who underwent AAA repair emergently, died unexpectedly 7 days after the discharge due to massive pulmonary embolism. The clinical success and the freedom from reintervention during the median follow-up of 12 months (interquartile range [IQR] 12-18), were 97%. One patient presented with disabling intermittent claudication at third month postoperatively, and the computed tomographic angiography (CTA) revealed thrombosis of one of the iliac endografts (3%). The patient underwent femorofemoral bypass with an uneventful postoperative course and immediate relief of the symptoms. One type II endoleak was spontaneously resolved on the sixth month. Sac shrinkage (>3 mm) was registered in 12 patients (35%), but the sac size was stable in the remaining 22 (65%) patients.

CONCLUSIONS

The preliminary outcomes of the Altura endograft seem to be promising, suggesting that the endograft could be safely used either in elective or emergent situations. Further studies with a major number of participants are needed to document its technical and clinical performance, especially in emergency situations that could be amenable to improvement.

The Altura endograft system for endovascular aneurysm repair: presentation of its unique design with clinical implications

INTRODUCTION

The Altura aortic endograft for the treatment of abdominal aortic aneurysms (AAA) consists of two separate components with a proximal double D-shaped design. The braided endoskeleton of the endograft is attached only at the proximal and distal ends of the inner surface of the fabric resulting in adjustable length of the Altura components. To ensure optimal orientation and sealing, the design of Altura permits collapse, readjustment, and deployment of the repositioned D-shaped endografts.

AREAS COVERED

Since this new endograft design by Lombard presents unique characteristics, the aim of this article is to present its unique structure and deployment method and discuss its applicability, indications and associated concerns.

EXPERT OPINION

The Altura endograft revolutionizes the mechanism of infrarenal sealing by containing no main body at all. This feature allows ideal treatment of AAA with considerable offset of the renal arteries and permits also relining in cases of failing endografts or in cases where the short length of existing structures precludes deployment of conventional bifurcated endografts.

The Incraft stent graft for the treatment of abdominal aortic aneurysms: an iliac-friendly device with an effective conventional proximal sealing mechanism

INTRODUCTION

The Incraft aortic stent graft (Cordis, Bridgewater, NJ, USA) is a trimodular endovascular stent graft with a conventional suprarenal active fixation specifically designed to overcome the anatomic limitation of small, stenotic, and tortuous iliac vessels.

AREAS COVERED

The present article provides a complete description of the Incraft stent graft, its clinical performance, its technical characteristics as well as a comparison with other competitive endografts.

EXPERT OPINION

The Incraft stent graft is an EVAR ultra low-profile device initially designed for overcoming the limitation of the hostile iliac anatomy. Recently, the device is being increasingly used in real-world conditions and not only in complex iliac anatomies with good mid-term results. Whether it remains a useful EVAR toolbox or will become a workhorse endograft is yet to be determined.

Proximal iliac limb extension and embolization: a new technique of complete endovascular management of an unfavorably sited type III endoleak

Type III endoleak is an uncommon but life-threatening complication of endovascular aortic repair, and such leaks at certain sites can be challenging to treat through an endovascular route. A 77-year-old man presented with severe abdominal pain and was found to have an abdominal aortic aneurysm with contained rupture due to an unfavorably cited type IIIb endoleak. He was successfully treated with an endovascular approach using bilateral iliac limb proximal extension combined with embolization of endoleak sac, endoleak site and the feeding recess, preserving flow through both the iliac limbs obviating the need for an additional femorofemoral bypass. The patient improved clinically and had a favorable long-term follow-up profile.

Stent-Graft Relining Using the Altura Endograft for Type Ia and IIIb Endoleaks after Kissing Iliac Arteries Stent

A 79 years old man, affected by serious comorbidities, occurred to the Emergency Room of our Hospital complaining abdominal pain. He was previously submitted to kissing iliac arteries stent for iliac aneurysms. An urgent CT scan showed a type Ia and a type IIIb endoleaks with left common iliac artery enlargement, occlusion of both hypogastric arteries and inferior mesenteric artery, and a severe stenosis of the right iliac external artery. We opted for a relining with a two-piece D-shaped Altura endograft for the aorta, with bilateral iliac components, landing at the level of the external iliac arteries. Postoperative course was uneventful with no endoleak or endograft migration on CT scan control at 6 months.

An update on the improvement of patient eligibility with the use of new generation endografts for the treatment of abdominal aortic aneurysms

PURPOSE

Endovascular aneurysm repair (EVAR), performed within device instructions for use (IFU), offers improved outcomes. New endograft designs attempt to increase eligibility rates of abdominal aortic aneurysm (AAA) patients treated within device IFU. We aim to examine the anatomic suitability of the Ovation endograft in our AAA patients and compare it with the other contemporary devices.

RESEARCH DESIGN AND METHODS

Three-hundred and seven consecutive elective AAA patients treated during a 5-year period were included. Patient-specific anatomic characteristics were based on endograft IFUs to determine eligibility rates of each system.

RESULTS

Two-hundred-twenty-five patients underwent EVAR and 82 open surgery. Ineligibility for device implantation was significantly lower for the Ovation iX system (32%) compared to other devices (AFX-2:49%, Altura:49%, Anaconda:54%, Endurant II:46%, Excluder:52%, Excluder Conformable:39%, Incraft:43%, E-Tegra:52%, Zenith-Alpha:52%; P-Value<0.001). The Alto system (next-generation Ovation) achieved an even lower ineligibility rate of 30% (P = 0.008). Short proximal aortic neck length followed by access vessel inadequacy were the primary reasons for ineligibility.

CONCLUSION

The Ovation-iX included more patients with anatomic characteristics within device IFUs resulting in improved eligibility rates compared with the rest of contemporary devices. Its evolution, the Alto system, further improves patient eligibility due to the inclusion of shorter aortic necks.

EXPERT OPINION

The Ovation iX system presented a significantly better performance and was eligible for use in a greater number of patients in our series of elective AAA repairs, accommodating patient-specific aortic anatomies. Of course, performing EVAR within the endograft's IFU is important to achieve optimal and durable outcomes. The proximal neck length followed by the size of the access vessels are the two more common factors resulting in loss of eligibility. Except for overall eligibility rates, a case by case decision must be made on which is the most suitable device for each patient, based on the specific characteristics of its unique anatomy.

Innovative textile structures designed to prevent type III endoleaks in endovascular stent-grafts

The damage caused to the fabric of endovascular stent-grafts most often occurs at the contact zones between the fabrics where they are attached to the apices of Z-shaped stents as a result of normal physiologic pulsatile movement within angulated vessels in vivo. Although design improvements were made over the years, the risks were not fully eliminated even with the newer M-shaped stent reconfiguration. In this study, we proposed to create and manufacture a novel fabric for stent-grafts with specifically designed reinforced zones to enhance resistance to fabric abrasion. These reinforced zones are set at the vicinity of the apices of the Z-shaped stents and between two adjacent Z-shaped stents where folding and pleating are commonly observed to occur in angulated vessels. Three innovative weaving structures with two different types of yarns and two controls were designed and prepared. Two commonly used commercial devices supported, respectively, with ringed stents, and Z-shaped stents were selected as the references for comparison. Textile structures including thickness, water permeability, mechanical properties, (more specifically tensile and bursting stress, as well as fatigue simulation) were tested on all fabrics. Compared to commercially available plain weaves, the fabrics with locally reinforced zones showed improved mechanical characteristics and fatigue resistant properties. A fabric designed with specifically reinforced zones has now clearly been shown to effectively reduce the abrasion caused by the apices of Z-shaped stents. However, further optimization may still be possible.

A Unique Indication for the Altura Endograft to Repair Bilateral Common Iliac Artery Aneurysms Associated with a Short-Infrarenal Aorta

A 71-year-old man with end-stage renal disease on hemodialysis presented with bilateral common iliac artery aneurysms diagnosed during the workup of his chronic kidney disease. On computed tomography angiography, common iliac artery aneurysm diameters measured 6.1 cm on the right side and 3.1 cm on the left side. The infrarenal aorta also had a small 3.2-cm aneurysm, but the length from the lowest left renal to the aortic bifurcation was only 6.7 cm, precluding use of most bifurcated endografts. Following an uneventful staged preoperative internal iliac artery embolization, a two-piece D -shaped Altura endograft for the aorta, with bilateral iliac components, landing at the level of the external iliac arteries was successfully performed. Postoperative course was uneventful with no endoleak or endograft migration on computerized tomographic angiography 45 days later, although billowing mimicking an endoleak was evident and will be closely followed.

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.

Stent-Graft Relining by Combined Aortic Cuff with Double-D Technique for Type IIIb or V Endoleak after Endovascular Aneurysm Repair: A Case Report

We report the case of a 83-year-old man with aneurysmal sac enlargement after endovascular aneurysm repair for an abdominal aortic aneurysm, despite no overt endoleak (EL) detected on imaging. Occult type II EL was suspected, and treatment was performed. However, the aneurysm continued to enlarge. Thus, we diagnose with type V EL as exclusion diagnosis. We combined an aortic cuff and stent-graft leg to cover the initially inserted stent graft, as a diagnostic treatment for unrefined type IIIb EL. Subsequently, the aneurysm diameter decreased. This technique and concept may be effective for type V EL, which may include another type occult EL.