A Misdiagnosed Case of Endoleak Type-III Caused by Inadvertent Bilateral Limb Insertion in the Same Limb Gate of the Ovation Endograft

We describe an infrequent case of endoleak Type-III due to an unrecognized, inadvertent bilateral limb deployment into the same limb gate of the Ovation aortic endograft, accompanied by thrombosis and acute ischemia. The following computed tomography angiography revealed the open limb gate with the characteristic of radio-opaque polymer in the sealing rings. Intraoperative angiographies via the brachial route identified the open limb gate and facilitated the successful use of an occluding plug to manage the Type-III endoleak.

The Polymer-Based Technology in the Endovascular Treatment of Abdominal Aortic Aneurysms

An abdominal aortic aneurysm (AAA) is a dilatation of the abdominal aorta that progressively grows until it ruptures. Treatment is typically recommended when the diameter is more than 5 cm. The EVAR (Endovascular aneurysm repair) is a minimally invasive procedure that involves the placement of an expandable stent graft within the aorta to treat aortic disease without operating directly on the aorta. For years, stent grafts' essential design was based on metallic stent frames to support the fabric. More recently, a polymer-based technology has been proposed as an alternative method to seal AAA. This review underlines the two platforms that are based on a polymer technology: (1) the polymer-filled endobags, also known as Endovascular Aneurysm Sealing (EVAS) with Nellix stent graft; and (2) the O-ring EVAR polymer-based proximal neck sealing device, also known as an Ovation stent graft. Polymer characteristics for this particular aim, clinical applications, and durability results are hereby summarized and commented critically. The technique of inflating endobags filled with polymer to exclude the aneurysmal sac was not successful due to the lack of an adequate proximal fixation. The platform that used polymer to create a circumferential sealing of the aneurysmal neck has proven safe and effective.

Endovascular aortic repair in patients with challenging anatomies: the EXTREME study

AIMS

The aim of this study was to report the 30-day technical and clinical success with endovascular repair using the ultra-low-profile Ovation stent graft in patients judged to be outside the instructions for use (IFU) for conventional endografts, while amenable to treatment within the IFU for Ovation.

METHODS AND RESULTS

One hundred and twenty-two patients (78.65±7.67 years; 111 male) were enrolled. Patients were evaluated as being outside the IFU for standard endografts because of the absence of a suitable proximal aortic neck in 109 cases (89.3%), of inadequate access vessels in 13 (10.7%), or both in 111 (90.9%). Mean aneurysm (abdominal aortic aneurysm [AAA]) diameter was 52.96±10.1 mm; mean aortic neck length was 7.75±6.05 mm. Technical success (98.4%) was achieved in all but two patients due to a type Ia endoleak. At completion angiography, 15 (12.3%) patients presented a type II endoleak. All patients underwent 30-day follow-up. Primary clinical success at one month was 96.8%, assisted clinical success 98.4%. There were no type I endoleaks, while 12 (9.8%) type II endoleaks were still evident, in the absence of sac expansions. Two patients (1.6%) presented an asymptomatic limb occlusion.

CONCLUSIONS

Our experience suggests that, in a selected population of patients with challenging anatomy outside the IFU for conventional endografts, endovascular aneurysm repair (EVAR) using the Ovation stent graft can be performed safely with satisfactory immediate outcomes.

An update on the ovation abdominal stent graft for the treatment of abdominal aortic aneurysms: current evidence and future perspectives

Introduction: The Ovation stent-graft has presented satisfactory mid-term results in the management of abdominal aortic aneurysms (AAA). Its unique design with uncoupling of fixation and sealing and the lowest profile in the market has expanded the treatment in AAA with challenging neck anatomies and, especially, in the females presenting mostly with narrow iliac access vessels. Morever, a new design modification, the Ovation Alto was recently introduced in the Market, while certain off-label uses of the Ovation in treating either juxtarenal- or short-necked AAA have been proposed. Areas covered: Aim of this article was to present the current articles with the long-term results of the Ovation endograft and discuss the new developments and modifications in its use. Expert commentary: the Ovation stent-graft exhibits very satisfactory clinical long-term results in AAA treated within the instructions-for-use, expands significantly the treatment of AAA in females and overcomes reliably challenging anatomical issues of the infrarenal neck that would render these cases ineligible for treatment with any other endograft. Εxperience with the specific, unique technical features of Ovation as well as careful selection of patients and meticulous preoperative study of the AAA anatomy are key-elements to the successful performance of this endograft.

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.

Tips to Ensure Optimal Ring Apposition of the Ovation Stent Graft in Challenging Necks of Abdominal Aortic Aneurysms

The Ovation stent graft has been recently introduced for endovascular repair of abdominal aortic aneurysms. Its sealing mechanism is based on a pair of polymer-filled inflatable rings. Based on our experience, we describe useful tips to optimize the use of Ovation in thrombosed or severely angulated necks.

The great choke, Ovation® aortic body graft stenosis

Introduction

Abdominal endovascular aneurysm repair is a minimally invasive alternative to major open surgery for the repair of abdominal aortic aneurysms that results in reduced recovery times and early survival rates.

Methods

The TriVascular Ovation® Abdominal Stent Graft System is a low-profile endovascular device with active fixation used for endovascular aneurysm repair. The stent graft is designed to reline the diseased vasculature, providing an endovascular blood conduit for isolating the aneurysm from the high-pressure flow of blood, thereby reducing the risk of rupture. The stent graft is a modular configuration comprised of an aortic body section, iliac limbs, and iliac extensions as required. Results and Conclusion: We present a case of symptomatic aortic body graft stenosis in the unsupported segment below the O-rings, 26 months after the treatment of abdominal aortic aneurysm with Ovation® Abdominal Stent Graft System. The successful repair was performed by ballooning the stenotic area which resulted in complete resolution of the symptoms.

A clinical update on the mid-term clinical performance of the Ovation endograft

INTRODUCTION

The Ovation stent-graft uncouples the steps of fixation and sealing via a pair of polymer-filled inflatable rings. Apart from the well-documented early results, newer data emerged for mid-term results of Ovation and are presented in this review.

AREAS COVERED

Aim of this article was to report all current studies with the mid-term results of the particular endograft, the incidence of complications and failure, and discuss their management.

EXPERT COMMENTARY

The Ovation stent-graft exhibits very satisfactory clinical mid-term results in abdominal aortic aneurysms treated within the instructions-for-use. It can also have a very promising role in challenging neck anatomies with conical shape and presence of thrombus or calcification. However, this should be not considered a panacea and long-term results are needed to validate this intriguing aspect.

Laser Fenestration of Aortic Stent-Grafts Followed by Noncompliant vs Cutting Balloon Dilation: A Scanning Electron Microscopy Study

Purpose: To examine the effects of in situ laser fenestration and subsequent balloon dilation (noncompliant vs cutting) on the graft fabric of 4 aortic stent-graft models. Method: In an in vitro setup, the Zenith TX2, Talent, Endurant, and Anaconda aortic stent-grafts (all made of polyester graft material) were subjected to laser fenestration with a 2.3-mm-diameter probe at low and high energy in a physiologic saline solution followed by balloon dilation of the hole. For the first series of tests, 6-mm-diameter noncompliant balloons were used and replaced for the second series by 6-mm-diameter cutting balloons. Each procedure was performed 5 times (5 fenestrations per balloon type). The fenestrations were examined visually and with light and scanning electron microscopy. Results: Each fenestration demonstrated various degrees of fraying and/or tearing regardless of the device. The monofilament twill weave of the Talent endograft tore in the warp direction up to 7.09±0.46 mm at high energy compared with 2.41±0.26 mm for the Endurant multifilament device. The fenestrations of the 3 endografts with multifilament weave (Zenith, Anaconda, and Endurant) showed more fraying; fenestration areas in the multifilament Endurant were >10 mm2 at low and high energy. The fenestrations were free of melted fibers, but minor blackening of the filaments was observed in all devices. Overall, the cutting balloons resulted in worse tearing and damage. Of note, the edges of the dilated laser-formed fenestrations of the Talent and the Endurant grafts demonstrated evidence of additional shredded yarns. Conclusion: In situ fenestration does not cause any melting of the polyester; however, the observed structural damage to the fabric construction must be carefully considered. Cutting balloons caused various levels of tearing compared to the noncompliant balloons and cannot be recommended for use in this application. Rather, noncompliant balloons should be employed, but only with endografts constructed from multifilament yarns. The use of in situ fenestration must be restricted to urgent and emergent cases until long-term durability can be determined.

Extrinsic Compression of the Ovation Stent-Graft Following Glue Embolization for Type II Endoleak: An Unusual Complication

PURPOSE

To describe a case of extrinsic compression of the Ovation stent-graft following glue embolization for type II endoleak.

CASE REPORT

A 75-year-old man with a past history of ischemic heart disease and endovascular aneurysm repair with an Ovation stent-graft was admitted for treatment of type II endoleaks from the right L2 and left L4 lumbar arteries with egress via the inferior mesenteric and right L4 lumbar arteries, respectively. Successful embolization was performed via a translumbar sac puncture with a combination of coils and histoacryl glue. On final angiography severe lumen narrowing of the unsupported portion of the Ovation stent-graft was seen owing to extrinsic compression by the glue. This was successfully salvaged with percutaneous transarterial kissing balloon angioplasty.

CONCLUSION

Aortic lumen narrowing caused by extrinsic compression of an Ovation stent-graft following glue embolization of type II endoleak is an unusual and potentially problematic complication.

Rationale for a new registry on EVAR: The EXTREME study

To report rationale of a physician-initiated study: Expanding Indications for Treatment with Standard EVAR in Patients with Challenging Anatomies, a Multi-Centric Prospective Evaluation - EXTREME.

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Long term result after EVAR for AAA are still considered one of the main limits to the application of this treatment.

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According with IFU and guidelines, EVAR still has several anatomical limitation.

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Ovation Stent-Graft is an unique devices allowing to implement the range of patients amendable to be treated by EVAR.

Midterm Results of Proximal Aneurysm Sealing With the Ovation Stent-Graft According to On- vs Off-Label Use

Purpose: To compare the use of the Ovation stent-graft according to the ≥7-mm neck length specified by the original instructions for use (IFU) vs those treated off-label (OL) for necks <7 mm long. Methods: A multicenter retrospective registry (TriVascular Ovation Italian Study) database of all patients who underwent endovascular aneurysm repair with the Ovation endograft at 13 centers in Italy was interrogated to identify patients with a minimum computed tomography (CT) follow-up of 24 months, retrieving records on 89 patients (mean age 76.4±2.4 years; 84 men) with a mean follow-up of 32 months (range 24–50). Standard CT scans (preoperative, 1-month postoperative, and latest follow-up) were reviewed by an independent core laboratory for morphological changes. For analysis, patients were stratified into 2 groups based on proximal neck length ≥7 mm (IFU group, n=57) or <7 mm (OL group, n=32). Outcome measures included freedom from type Ia endoleak, any device-related reintervention, migration, and neck enlargement (>2 mm). Results: At 3 years, there was no aneurysm-related death, rupture, stent-graft migration, or neck enlargement. There were no differences in terms of freedom from type Ia endoleak (98.2% IFU vs 96.8% OL, p=0.6; hazard ratio [HR] 0.55, 95% CI 0.02 to 9.71 or freedom from any device-related reintervention (92.8% IFU vs 96.4% OL, p=0.4; HR 2.42, 95% CI 0.34 to 12.99). In the sealing zone, the mean change in diameters was −0.05±0.8 mm in the IFU group and −0.1±0.5 mm in the OL group. Conclusion: Use of the Ovation stent-graft in patients with neck length <7 mm achieved midterm outcomes similar to patients with ≥7-mm-long necks. These midterm data show that the use of the Ovation system for the treatment of infrarenal abdominal aortic aneurysm is not restricted by the conventional measurement of aortic neck length, affirming the recent Food and Drug Administration–approved changes to the IFU.

Anaphylactic Reaction during Implantation of Ovation Abdominal Stent Graft in Patients with Abdominal Aortic Aneurysm

The Ovation Abdominal Stent Graft System is a trimodular endoprosthesis planned to overcome the limitations of currently available stent grafts, allowing complex iliac and femoral access and providing a proximal seal in challenge infrarenal neck morphology. The proximal sealing is achieved by means of a network of inflatable rings filled with low-viscosity radiopaque polyethylene glycol-based polymer during stent-graft deployment. The leakage of polymer outside the channel to fill the rings into the vascular system may induce an hypersensitivity reaction and anaphylactic shock. We report a case of anaphylactic reaction during Ovation Abdominal Stent Graft System implantation. The endovascular procedure was successfully concluded.