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Since the introduction of endovascular aortic repair (EVAR) for treatment of abdominal aortic aneurysms (AAAs), progressive improvements in results have been achieved. However, conventional bifurcated stent grafts have been proven to have a nonnegligible risk of failure and secondary intervention, principally due to the lack of adequate proximal sealing. The unique AFX 2 Endovascular AAA System (Endologix, Irvine, CA) unibody device, which provides different sealing and fixation features compared with conventional devices, seems to overcome these limitations.
The aim of this study is to evaluate intraoperative, perioperative, and postoperative results in patients treated with the AFX 2 Endovascular AAA System endografts for elective AAA repair in a large cohort of consecutive patients.
All eligible EVAR patients will be included in this observational, multicenter, prospective, nonrandomized study. The number of patients to be enrolled is 500.
The primary endpoint of the study is to evaluate the technical and clinical success of EVAR with unibody endografts in short- (90-day), mid- (1-year), and long-term (5-year) follow-up periods. The following secondary endpoints will also be addressed: operative time, intraoperative radiation exposure, contrast medium usage, AAA sac shrinkage at 12-month and 5-year follow-up, and any potential role of patients’ baseline characteristics and device configuration on primary endpoint. The actual start date of the investigation was November 2019. The final patient is expected to be treated by the end of December 2020, and the estimated study completion date is December 2025.
This study will provide verified real-world data on AAAs treated by AFX 2 endografts and followed for a long-term interval.
PRR1-10.2196/16959
In recent years, endovascular aortic repair (EVAR) has emerged as a safe and valid option for treatment of abdominal aortic aneurysms (AAAs) (
The AFX 2 Endovascular AAA System is essentially composed of two distinct elements: the bifurcated stent graft and the proximal and iliac limb extension stent grafts.
The bifurcated element is the primary component that is delivered into the patient’s aorta. All bifurcated stent grafts consist of a unibody configuration (an aortic main body with two attached iliac legs). The main body and each iliac leg are constructed from a single wire. The main body is manufactured in sizes ranging from 22 mm to 28 mm. The iliac legs are 13 mm to 20 mm in diameter for all sizes of bifurcated stent grafts.
The proximal and iliac limb extension stent graft components are used to extend the lengths of implanted bifurcated components. The AFX 2 Endovascular AAA System proximal extensions (Vela) are available in suprarenal and infrarenal configurations and use a circumferential radiopaque marker for identification of the proximal graft fabric line.
According to current instructions for use, the following anatomical criteria are required.
Adequate iliac or femoral access compatible with the required delivery systems (diameter 6.5 mm)
Nonaneurysmal aortic neck between the renal arteries and the aneurysm with a length 15 mm, a diameter ≥18 mm and ≤32 mm, and a neck angle ≤60° to the body of the aneurysm
Aortic length ≥1.0 cm longer than the body portion of the chosen bifurcated model
Common iliac artery distal fixation site with a distal fixation length ≥15 mm, ability to preserve at least one hypogastric artery, a diameter ≥10 mm and ≤23 mm, and an iliac angle ≤90° to the aortic bifurcation
Extension stent grafts must have the ability to overlap the bifurcated stent graft by at least 30 to 40 mm proximally and at least 15 to 20 mm distally
Some elegant papers have been published on this unique device [
Similar results were reported by Qu and Raithel [
Moreover, Silingardi et al [
The promising data from these studies should be confirmed by prospective data collecting in a large consecutive cohort of patients using the latest generation unibody device implantation. Therefore, this study aims to evaluate intraoperative, perioperative, and postoperative results in patients treated with AFX 2 Endovascular AAA System endografts for elective AAA repair in a large cohort of consecutive patients.
The aim of this study is to evaluate intraoperative, perioperative, and postoperative results in patients treated using the latest generation AFX 2 Endovascular AAA System endograft for elective AAA repair in a multicentric study.
A total of 46 south European high-volume centers across Italy and Spain were involved in the Less Invasive and Faster Endovascular Aortic Repair Study. In a 12-month period from October 2018 to October 2019, mean EVAR procedures per center were 49.56 (range 20-140), while mean AFX procedures per year per center were 14.54 (range 10-57).
All consecutive eligible patients submitted to EVAR by AFX 2 Endovascular AAA System implantation will be included in the analysis. Patients will be submitted to EVAR procedures on the basis of their own preferences, anatomical features, and the operator’s experience.
In light of the participating centers’ numbers and activity volumes, an estimated 500 patients submitted to EVAR with AFX 2 should be enrolled. The sample size is low enough to obtain statistically significative results, according to previous published studies [
Prior to enrollment in the clinical investigation, patients will be evaluated by their physician for the inclusion criteria. Each patient’s medical condition should be stable, with no underlying medical condition that would prevent them from performing the required testing or completing the study. Patients should be geographically stable, willing and able to cooperate in this clinical study, and remain available for a midterm follow-up. Patients who do not wish to participate in this study can obtain the best available EVAR therapy as indicated, that is refusal to participate in this study will in no way affect their care at the institution. Inclusion and exclusion criteria are detailed in
Elective abdominal aortic aneurysm patients that should be treated by standard abdominal endovascular aneurysm repair, according to Endologix AFX unibody device’s instructions for use
Patient is willing to comply with specified follow-up evaluations at the specified times for the duration of the study
Patient is >18 years of age
Patient, or their legal representative, understands the nature of the procedure and provides written informed consent prior to enrollment in the study
Abdominal endovascular aneurysm repair performed in urgent or emergent setting
Patients treated outside Endologix AFX unibody device’s instructions for use
Patients refusing treatment
Patients for whom antiplatelet therapy, anticoagulants, or antihypertensive drugs are contraindicated
Patients with a history of prior life-threatening contrast medium reaction
Life expectancy is less than follow-up period
This study respects all the principles reported in the current version of the Helsinki declaration (2013). According to the current International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use and Good Clinical Practice guidelines, each investigator is responsible for the regularity of the study. The aim of these standards is to assure the safety and comfort of all people recruited in the study. The study protocol and the written informed consensus form will be submitted to the local ethics committees for review.
AAA morphology will be assessed by OsiriX MD (PIXMEO, Geneva, Switzerland) on a regular Mac OS computer in one preoperative, contrast-enhanced, computed tomography angiography (CTA) [
A patient is considered enrolled in the study if there is full compliance with the study inclusion and exclusion criteria.
Clinical data will be collected at patient enrollment, the EVAR procedure, discharge, planned follow-ups (ie, 1-3 months and 12 months postprocedure, and yearly thereafter), unplanned or interim follow-ups, and patient death. CTAs are mandatory within 90 days and then at 1 and 5 years after the index procedure. The duplex ultrasound scan will be performed at the same follow-up interval and also at 24, 36, and 48 months. A new CTA will be performed in case of unexpected events during follow-up.
The primary endpoint of the study is to evaluate the technical and clinical success of EVAR with unibody endografts in short- (90-day), mid- (1-year), and long-term (5-year) follow-up periods.
Technical success was defined as the correct graft deployment without any unintentional occlusion of the aortic visceral branches or both hypogastric arteries, with aneurysm exclusion confirmed by the intraoperative angiography, no signs of type I or III endoleak, or conversion to open surgery.
Clinical success included successful deployment of the endovascular device at the intended location without death as a result of aneurysm-related treatment, type I or III endoleak, graft infection or thrombosis, aneurysm expansion (>5 mm), aneurysm rupture, or conversion to open repair (OR), as well as the presence of graft dilatation of 20% or more by diameter, graft migration, or a failure of device integrity [
The clinical and technical success were defined as assisted in cases of unplanned endovascular procedures, or secondary if unplanned surgery is necessary.
The following secondary endpoints will be also addressed: operative time, intraoperative radiation exposure, contrast medium usage, AAA sac shrinkage at 12-month and 5-year follow-ups, and any potential role of patients’ baseline characteristics and device configuration on primary endpoint.
Patient data will be captured electronically using a computer-based platform accessible to all investigators. Descriptive data summaries will be used to present and summarize the collected data. For categorical variables such as gender, frequency distributions and cross tabulations will be given. For numeric variables such as patient age, minimum, maximum, mean, median, and standard deviation will be calculated. For all variables, a 95% confidence interval for the relevant parameters of the underlying distribution will be calculated. For all time-dependent events, life tables will be calculated using the Kaplan-Meier estimate method for a period starting on the date of the procedure up to and including all follow-up visits. Stratification to risk factors will be performed and the logrank test will be used to compare the different outcomes; associated
All preoperative and follow-up CTAs were assessed and independently evaluated by two experienced vascular surgeons at core lab centers. Disagreements will be discussed and resolved by consensus.
All information and data concerning patients or their participation in this clinical investigation will be considered confidential. Only authorized personnel will have access to these confidential files. Authorized personnel of health authorities will have the right to inspect and copy all records pertinent to this clinical investigation. All data used in the analysis and reporting of this clinical investigation will be anonymized.
The actual start date of the investigation was November 2019. It is anticipated that 500 patients will be recruited to the study. The final patient is expected to be treated by the end of December 2020 and the estimated study completion date is December 2025. After data analysis, results will be shared with each investigator.
In the last years, EVAR has become the standard of care for AAA treatment, and nowadays it represents the recommended modality of treatment according to the European Society for Vascular and Endovascular Surgery and the Society for Vascular Surgery guidelines [
However, the major randomized controlled trials (RCTs) on EVAR vs OR have not reached definitive conclusions. In 2004, the results of the first two RCTs were published [
The EVAR-1 trial described a clear advantage of EVAR compared to OR at 30 days. Greenhalgh and collaborators [
More enthusiastic conclusions came from the analysis of the Dutch Randomised Endovascular Aneurysm Management (DREAM) trial, reporting an operative mortality rate of 4.6% in the OR group (8/174 patients) and 1.2% in the EVAR group (2/171 patients) in a series of patients treated between 2000 and 2003, resulting in a risk ratio of 3.9 (95% CI 0.9-32.9). The combined rate of operative mortality and severe complications was 9.8% in the OR group (17/174 patients) and 4.7% in the EVAR group (8/171 patients), resulting in a risk ratio of 2.1 (95% CI 0.9-5.4). The authors concluded that EVAR was preferable to OR [
However, long-term follow-up was demanded to determine whether advantages persisted, and 1 year later, both trials published their midterm results [
The Open Versus Endovascular Repair (OVER) trial, which included patients treated between 2002 and 2007, was published in 2010. On the basis of a mean follow-up of 1.8 years, the OVER trial results showed that perioperative mortality was lower for EVAR than for OR (0.5% vs 3.0%;
A year later, a French RCT (ACE Trial) reported quite different results with no differences between EVAR and OR. Although only low to intermediate risk patients were enrolled, OR and EVAR offered no difference in survival (96.5% vs 95.2% at 1 year, and 86.7% vs 86.3% at 3 years) or in major and minor complications (95.9% vs 93.2% at 1 year, and 85.1% vs 82.4% at 3 years) [
These results led to a change in point of view: EVAR was considered as feasible as OR without any advantages, even in the short-term. The same year, a new US study, with a 6-year follow-up on 45,652 Medicare beneficiaries undergoing EVAR or OR in the period between 2001 and 2004, was analyzed to clarify the late results of endovascular procedures. Throughout follow-up, overall reintervention or readmission rates were similar with the two repair methods but slightly more common after EVAR than OR (7.6 vs 7.0/100 person-years;
In 2016, the long-term results of the EVAR-1 RCT were published. In a mean of 12.7 years for follow-up, Patel et al [
However, late results from the OVER trial were published. In Lederle’s [
Notably, all these trials reported only few data or none at all on patients treated by unibody stent graft implantation. As mentioned above, AFX 2 Endovascular AAA System endografts are completely different from a technical and philosophical point of view from all other modular devices, and it seems to also provide different results. In fact, different studies have already demonstrated the advantages of this endograft and its safety and efficacy in short and midterm follow-up periods [
Given the lack in current literature of effective data on unibody endograft results, the aim of our prospective study is addressing intraoperative, perioperative, and postoperative results in patients treated by the latest generation AFX 2 Endovascular AAA System endografts for elective AAA repair in a multicentric study.
EVAR Overview.
abdominal aortic aneurysm
computed tomography angiography
Dutch Randomized Endovascular Aneurysm Management
endovascular aortic repair
hazard ratio
open repair
Open Versus Endovascular Repair
randomized controlled trial
The LIVE Study Collaborators are as follows: Giancarlo Accarino; Dimitri Apostolou; Guido Bajardi; Stefano Bartoli; Filippo Benedetto; Franco Briolini; Stefano Camparini; Emidio Costantini; Giovanni Credi; Ruggiero Curci; Raffaello Dallatana; Gianmarco de Donato; Carlo Dionisi; Vittorio Dorrucci; Leonardo Ercolini; Gianfranco Fadda; Mauro Ferrari; Loris Flora; Andrea Gaggiano; Roberto Gattuso; Franco Grego; Sabrina Grimaldi; Giovanni Impedovo; Arnaldo Ippoliti; Antonio Jannello; Sergio Losa; Nicola Mangialardi; Isaac Martinez; Javier Martinez; Stefano Michelagnoli; Giancarlo Palasciano; Vincenzo Palazzo; Domenico Palombo; Raffaele Pulli; Sonia Ronchey; Giovanni Rossi; Antonino Scolaro; Gianantonio Simoni; Francesco Spinelli; Francesco Talarico; Maurizio Taurino; Marco Trogolo; Nicola Tusini; Gianfranco Veraldi; Pier Francesco Veroux; Gennaro Vigliotti; and Pietro Volpe.
None declared.