Real-Life Experience with Ovation Stent Graft: Lesson Learned from the First One Hundred Fifty Treated Patients

Low profile endografts for the endovascular treatment of abdominal aortic aneurysms

INTRODUCTION

Favorable midterm outcomes have been reported with the use of low-profile endografts (LPE), but long-term data is still needed. Furthermore, it is unclear if each of these LPE may have advantages over the other, which may, in turn, affect the outcomes. We systematically reviewed the literature about complications and reintervention rates of patients submitted to endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) using LPE.

MATHERIALS AND METHODS

A literature search was conducted including articles that reported 30-days and follow-up mortality, complications, and reintervention rates of patients treated with EVAR using Incraft (Cordis), Zenith LP/Alpha (Cook Medical Inc) and Ovation (Endologix) endografts.

RESULTS

36 papers were evaluated, reporting results of 582 patients treated with Zenith device, 1211 with Incraft and 3449 with Ovation. During follow up, similar survival and freedom from reintervention rates were reported among the various types of endograft both at 1 and 3 years. The incidence of limb stenosis/kinking was significantly higher in patients treated with Zenith LP/Alpha (2.1%, P = 0.008), while the Incraft device had a significantly lower proportion of type III endoleaks (P < 0.001).

CONCLUSIONS

Long-term survival and freedom from reintervention rates were comparable among the three LPEs. The Cook Zenith device had the highest rates of limb stenosis/kinking, while the Incraft device had the lowest occurrence of type III endoleak.

PROSPERO

Registration number: CRD42022315875.

Is Evar Feasible in Challenging Aortic Neck Anatomies? A Technical Review and Ethical Discussion

Background: Endovascular aneurysm repair (EVAR) has become an accepted alternative to open repair (OR) for the treatment of abdominal aortic aneurysm (AAA) despite “hostile” anatomies that may reduce its effectiveness. Guidelines suggest refraining from EVAR in such circumstances, but in clinical practice, up to 44% of EVAR procedures are performed using stent grafts outside their instruction for use (IFU), with acceptable outcomes. Starting from this “inconsistency” between clinical practice and guidelines, the aim of this contribution is to report the technical results of the use of EVAR in challenging anatomies as well as the ethical aspects to identify the criteria by which the “best interest” of the patient can be set. Materials and Methods: A literature review on currently available evidence on standard EVAR using commercially available endografts in patients with hostile aortic neck anatomies was conducted. Medline using the PubMed interface and The Cochrane Library databases were searched from 1 January 2000 to 6 May 2021, considering the following outcomes: technical success; need for additional procedures; conversion to OR; reintervention; migration; the presence of type I endoleaks; AAA-related mortality rate. Results: A total of 52 publications were selected by the investigators for a detailed review. All studies were either prospective or retrospective observational studies reporting the immediate, 30-day, and/or follow-up outcomes of standard EVAR procedures in patients with challenging neck anatomies. No randomized trials were identified. Fourteen different endo-grafts systems were used in the selected studies. A total of 45 studies reported a technical success rate ranging from 93 to 100%, and 42 the need for additional procedures (mean value of 9.04%). Results at 30 days: the incidence rate of type Ia endoleak was reported by 37 studies with a mean value of 2.65%; 31 studies reported a null migration rate and 32 a null conversion rate to OR; in 31 of the 35 studies that reported AAA-related mortality, the incidence was null. Mid-term follow-up: the incidence rate of type Ia endoleak was reported by 48 studies with a mean value of 6.65%; 30 studies reported a null migration rate, 33 a null conversion rate to OR, and 28 of the 45 studies reported that the AAA-related mortality incidence was null. Conclusions: Based on the present analysis, EVAR appears to be a safe and effective procedure—and therefore recommendable—even in the presence of hostile anatomies, in patients deemed unfit for OR. However, in order to identify and pursue the patient’s best interest, particular attention must be paid to the management of the patient’s informed consent process, which—in addition to being an essential ethical-legal requirement to legitimize the medical act—ensures that clinical data can be integrated with the patient’s personal preferences and background, beyond the therapeutic potential of the proposed procedures and what is generically stated in the guidelines.

"Aortic Balloon-Molding" (ABM) During Ovation Endograft Implantation Expands Graft Use for Hostile Neck Anatomy

BACKGROUND

Challenging aortoiliac anatomy such as short neck and narrow access vessels is responsible for EVAR ineligibility in up to 50% of cases. The Ovation stent-graft helped widen the range of AAAs suitable for EVAR thanks to its low-profile delivery system and polymer-filled sealing rings. However, its advantages are offset by a tight sizing chart that can lead to increased risk of type Ia endoleak or endograft infolding from under or oversizing, respectively. We sought to assess the safety and efficacy of a novel endovascular technique developed to expand the use of the Ovation endograft while avoiding these issues.

METHODS

We conducted a retrospective review of all patients who underwent EVAR with the Ovation endograft at our institution between March 2019 and December 2020. "Aortic Balloon Molding" or ABM is a novel endovascular technique in which the graft is pre-cannulated and a compliant aortic balloon is inflated at the site of the graft's sealing rings during polymer administration. The technique was preferentially performed in patients with hostile neck anatomy (HNA) defined as any or all of angulation>60°, reverse taper configuration, ≥50% circumferential thrombus or calcification. Patients undergoing traditional deployment were compared to those in whom ABM was performed. Endpoints included neck-related adjunctive procedures, technical success, type Ia endoleak at completion angiogram and 1-year freedom from type Ia endoleak and migration.

RESULTS

A total of 43 patients were included in the study, of which, 26 (60.5%) were treated with the ABM technique. Mean follow-up was 7.9±6 months. Patients in the ABM group were more likely to have a reverse taper neck (61.5% vs. 41.2%, P=0.1), to have significant circumferential thrombus or calcium (23.1% vs. 5.9%, P=0.1) and to be treated outside of the Ovation IFU regarding anatomic characteristics (65.4% vs. 41.2%, P=0.1). Technical success was achieved in 100% of cases. However, patients in the ABM group were less likely to require a neck-related adjunctive procedure (7.7% vs. 23.5%, P=0.1). Only one type Ia endoleak was observed at completion angiogram in a patient treated without ABM. At one-year, freedom from type Ia endoleak or migration was 100% for both groups.

CONCLUSIONS

Aortic Balloon Molding proves to be a safe and effective adjunctive technique for the treatment of AAAs with hostile neck anatomy using the Ovation stent-graft. This may allow optimal endograft sizing to achieve adequate seal in complex aortic anatomies. Further research is warranted to evaluate the long-term outcomes of this technique.

Endovascular Juxtarenal Aortic Aneurysm Repair Using the ALTO Abdominal Stent Graft System: The First Case Series

The ALTO abdominal stent graft system (Endologix Inc., Irvine, CA, USA) is a latest-generation polymer-based device used to treat patients with abdominal aortic aneurysms. The present study describes the first case series of patients with abdominal aortic aneurysms, including two patients with juxtarenal aneurysms, treated using the ALTO stent graft system. Six males were treated using the ALTO device at a single public center. All procedures were uneventful, and the dosimetric results recorded in terms of kerma-area product and fluoroscopy time were similar to those reported in previous studies. At the 1-month follow-up, computed tomography angiography showed no evidence of endoleak, device migration, thrombosis, or structural graft failure. This clinical series demonstrates that the use of the ALTO stent graft system is associated with promising patient outcomes. Lifelong postoperative imaging surveillance may highlight possible late failures and suggest potential graft improvements.

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.

Multicenter Mid-term Results After Endovascular Aortic Aneurysm Repair with the Incraft® Device

OBJECTIVES

Durability after endovascular aortic aneurysm repair (EVAR) is considered an ongoing topic of investigation and was always a point of concern with smaller profile devices. Recently released five-year clinical trial results using the Incraft® ultralow profile device are encouraging. However, additional real-life experience will need to assist these initial findings. Herein, we investigated the outcomes after EVAR, in real world practice using the Incraft® endograft (EG).

MATERIAL AND METHODS

Seventy-seven patients with infrarenal abdominal aortic aneurysms (AAA) ≥50 mm in diameter treated with the Incraft® device in three vascular centers were enrolled from November 2015 to July 2018. Follow-up was completed in August 2020. Selection of EVAR using the Incraft® device was individualized according to aorto-iliac morphologic features, comorbidities, history of previous abdominal surgery and preference of the patient. At the early phase of the study, we specifically opted for preferential use of this low profile EG mainly in cases of small and tortuous iliac vessels (more challenging access routes). At later stages, it was used according to surgeon preference and not specifically in complex anatomies (real-world conditions). End-points included technical success, perioperative complications, 30-day survival, endoleg patency, presence of endoleaks, sac enlargement >5 mm and clinical success.

RESULTS

The primary technical success rate was 97.4% before the addition of an aortic cuff and iliac extension for a type Ia and type Ib endoleak respectively, and the repair of a maldeployment iliac component (primary-assisted and secondary technical success, 100%). Intraoperative small type II endoleaks (visible in final angiogram) were noted in 19 patients (24.7%). There were no intraoperative deaths from AAA rupture, primary conversions or conversions to aortounilateral grafts. Two complications occurred, necessitating hybrid techniques for repair (replaced of a dislodged endoleg and distal external iliac artery hemostasis). No deaths were reported within 30 days. Occlusion of an endoleg, was observed in two patients, 6 and 14 months respectively after implantation (2.6%), and were treated by femoral-femoral PTFE bypass after unsuccessful endovascular recanalization. The latter required open conversion, 3 mo later, to repair compromised flow to the inflow iliac axis. Three patients (3.9%) experienced sac enlargement >5 mm in diameter compared with the 1-month CT scan. All of these had type II endoleaks and two received embolization procedures. Eleven patients died from causes unrelated to AAA repair. Clinical success was 97.3%, 92.8% and 89.4% through 1, 2 and 3 years respectively.

CONCLUSIONS

EVAR with the Incraft® device might be considered a reliable option in real-world conditions and not specifically only in complex iliac anatomies.

Retroperitoneal Hematoma Caused by Suprarenal Stent Perforation Two Years after Ovation Abdominal Stent-Graft Implantation

Retroperitoneal hematoma due to late perforation of aortic wall endograft deployment is a rare but, potentially, fatal event. We report a case of symptomatic retroperitoneal hematoma due to aortic perforation by free flow barbs of Ovation Prime stent graft. The patient was successfully treated by celiac trunk embolization and aortic cuff placement. The patient was discharged with no further treatment. At 3-month follow-up, no complications were detected.

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.

Type 2 Endoleak Incidence and Fate After Endovascular Aneurysms Repair in a Multicentric Series: Different Results with Different Devices?

BACKGROUND

The aim of this work is describing incidence and fate of type 2 endoleaks (T2ELs) in a multicentric cohort of patients treated by endovascular aneurysms repair using the Ovation device (Endologix) and comparing them with a group treated using the Excluder (W. L. Gore & Associates).

METHODS

This is a retrospective study conducted on 261 patients treated using the Ovation device and 203 using the Excluder. Outcomes were intraprocedural, 30-day, 12-month, and mean time follow-up T2EL incidence and related reinterventions. Patent inferior mesenteric artery (IMA), ≥3 lumbar arteries (LAs), intrasac thrombus volume, the mean diameter of common and external iliac arteries, external iliac artery stenosis (>70%), diameter ≤5 mm, iliac tortuosity ratio ≤0.5, thrombosis, and calcification were noted and considered as potentially influencing outcomes.

RESULTS

Patients of the Ovation group presented significantly more thrombosed, calcified, and tortuous iliac vessels than those in the Excluder group. No significant differences were noted in sac thrombosis, IMA, and LA patency. At completion angiography, T2EL was evident in 57 Ovation and 46 Excluder patients (P = 0.832). At 1 month, it was evident in 33 Ovation group and 28 Excluder group patients (P = 0.726). At 12-month and mean time (30.14 months) follow-up, no differences were evident between the 2 groups (P = 0.940 and 0.951, respectively). The log-rank test showed that the rate of T2EL-related reintervention was not different between the 2 groups (P = 0.46). Regarding anatomical characteristics, a statistically significant difference was not observed between patients presenting or not with T2EL (P > 0.05).

CONCLUSIONS

Data showed no significant differences in terms of T2EL incidence between the 2 study groups. None of preoperative anatomical features were found to be significantly associated with the appearance of T2EL.