Background: Open repair remains the gold standard for fit patients with complex AAA. In the
      past decade, an evolution of devices, design, components, and delivery systems expanded the
      application of EVAR in these challenging anatomies. Fenestrated stent-grafts are now
      commercially available for the repair of complex AAA in the United States and Europe. Initial
      reports have demonstrated a high technical success rate, low renal dysfunction rate, and low
      morbidity and mortality, with promising short- and long-term results. Other reports have
      shown excessive morbidity and mortality with fenestrated EVAR (FEVAR). Studies comparing
      endovascular and open repair are sparse, especially when it concerns long-term outcomes.
      There are till nowadays only two propensity score-matched studies, one showing worse
      short-term and another long-term clinical outcome for fenestrated-branched EVAR (F/BEVAR)
      over open surgical repair (OSR).

      Aim: The aim of this study will be to compare F/BEVAR versus open AAA repair on short- and
      long-term clinical outcomes for the treatment of juxta- and pararenal AAA.

      Methodology: This is a prospective cohort study from the four high-volume AAA repair centers:
      Belgrade/Serbia, Bologna/Italy, Milan/Italy, Dijklander/Netherland, Amsterdam/Netherland, and
      Helsinki/Finland. Data will be collected on demographics, baseline comorbidities, AAA
      parameters (diameter and localization), laboratory values, intra-, and postoperative data.
      Follow-up examinations (clinical visits and color duplex ultrasonography, CT scans) will be
      performed 1, 6, and 12 months after the intervention, and annually thereafter. Propensity
      score analysis will be performed by matching open repair patients to endovascularly treated
      controlling for demographics and baseline comorbidities.

      Endpoints: Primary endpoints are all-cause mortality and the freedom from aortic-related
      reintervention. The secondary endpoint is the 30-day complication rate, especially acute
      kidney injury according to the RIFLE criteria.

Comparison of Outcomes of Complex Abdominal Aortic Aneurysm Treatment

Juxtarenal Aortic Aneurysm

Pararenal Aneurysm

Background Endovascular abdominal aortic aneurysm repair (EVAR) has gained widespread
      acceptance in the treatment of patients with abdominal aortic aneurysms (AAA). Prospective
      randomized trials (RCTs) have demonstrated several short-term advantages over open repair
      such as less blood loss, operative time, hospital stay, morbidity, and mortality. The
      applicability of EVAR is limited by the presence of inadequate neck or involvement of the
      visceral arteries. Thus consequently open AAA repair is now being performed primarily for
      complex aortic anatomies, such as juxtarenal and pararenal aneurysms. Open repair remains the
      gold standard for fit patients with complex AAA. In the past decade, an evolution of devices,
      design, components and delivery systems expanded the application of EVAR in these challenging
      anatomies. Fenestrated stent-grafts are now commercially available for the repair of complex
      AAA in the United States and Europe. Initial reports have demonstrated a high technical
      success rate, low renal dysfunction rate and low morbidity and mortality with promising
      short- and long-term results. Other reports have shown excessive morbidity and mortality with
      fenestrated EVAR (FEVAR). Studies comparing endovascular and open repair are sparse,
      especially when it concerns long-term outcomes. There are till nowadays only two propensity
      score-matched studies, one showing worse short-term and another long-term clinical outcome
      for fenestrated-branched EVAR (F/BEVAR) over open surgical repair (OSR). Vascular surgeons
      are therefore left with a paucity of data to guide decision-making.

      Study objectives:

        1. Primary aim: Compare Kaplan-Meier freedom from aortic related reintervention and
           all-cause mortality rate between endovascular and open repair group Primary endpoint:
           Kaplan-Meier survival rate and Kaplan-Meier aortic related reintervention rate after the
           patient recruitment ends

        2. Secondary aim: compare short term outcomes in terms of 30-day complications rate,
           especially acute kidney injury according to the RIFLE criteria Secondary endpoint:
           30-day complications rate, especially acute kidney injury according to the RIFLE
           criteria

      Inclusion criteria:

        -  All patients (over 18 years of age) with a history of juxta- and pararenal AAA repair
           from January 2011 to January 2021

        -  All management strategies will be included (endovascular and open)

      Exclusion criteria:

        -  Patients who are pregnant

        -  Patients who are under 18 years of age

        -  Patients who have ruptured AAA

        -  Patients with thoracoabdominal aortic aneurysm (ThAAA)

        -  Patients who have a mycotic AAA

        -  Patients with connective tissue disorder

      Sample size To ensure sufficient statistical power to answer hypothetical questions,
      approximately 700 subjects will be entered into the database. Aortic-related reintervention
      rate is the primary endpoint being used to calculate the sample size. Assuming a difference
      of 7% in the late reintervention rate between endovascular and open repair, 221 patients
      would be required in each arm to achieve a statistical power of 85% at p=0.05. With two arms
      (endovascular versus open), assuming a 20% rate of missing data, a total N of 550 patients is
      required.

      Research Design

      This is a prospective study including patients treated for juxta- and pararenal AAA from 2011
      through 2021 treated at six different vascular surgery centers:

        1. Clinic for Vascular and Endovascular Surgery, Belgrade, Serbia

        2. Department of Vascular Surgery, Policlinico S. Orsola-Malpighi, Bologna, Italy

        3. Department of Vascular Surgery, San Raffaele Hospital, Milan, Italy

        4. Department of Vascular Surgery, Dijklander Ziekenhuis, Hoorn, Netherlands

        5. Department of Vascular Surgery, Amsterdam University Hospital, Amsterdam, Netherlands

        6. Department of Vascular Surgery, Helsinki Unversity Hospital, Helsinki, Finland

      Procedures Involved The study does not involve any patient contact and will not impact the
      care that patients receive. Data regarding the patients will be compiled and analyzed to
      accomplish the proposed study objectives. Data collection will include demographic
      information, patient-related factors, and comorbidities, diagnostic imaging information,
      laboratory data, surgical procedure information, complications of the surgery, and outcomes.

      Multi-Institutional research After the data has been collected at a participating
      institution, the data will be transmitted to a central analytic center located at the Clinic
      for Vascular and Endovascular Surgery/Clinical Center of Serbia/Medical Faculty, University
      of Belgrade.

      Risks to Subjects As this is a prospective observational study, there is no potential for
      physical risks to subjects. There is a minimal risk of breach of confidentiality that could
      occur when patient information is collected and analyzed for the proposed study. However,
      appropriate measures will be taken to minimize the risk as much as possible. All information
      recorded will be de-identified. This study will abide by all regulations related to
      protecting human subjects and protected health information.

      Potential Benefits to Subjects There is no direct benefit to the subjects. However, future
      patients with juxta- and pararenal AAA may benefit from improved care as a result of this
      study.

      Statistics and Data Analysis Continuous variables will be described using the median and
      interquartile range or mean and standard deviation. Categorical variables will be described
      using frequencies and percentages. Group comparisons will be performed by using the Student
      t-test or Mann-Whitney U test, as appropriate. Categorical data will be expressed as
      percentages and were compared using the chi-square test or Fisher exact test. Propensity
      score analysis will be performed by matching endovascular to open surgery group in a 1:1
      ratio controlling for demographics, baseline comorbidities, and AAA parameters. Differences
      will be considered statistically significant at p < 0.05. The cumulative incidences of
      all-cause mortality and aortic-related complications will be estimated using the Kaplan-Meier
      method. Differences between curves will be tested using the log-rank test. Analyses will be
      done with SPSS software, version 20.0 (SPSS, Chicago, IL, USA).

      Conflict of Interest The investigators have no conflict of interest to report.

      Funding Source There are no plans to apply for grants or additional funding. No funding is
      required for the completion of this study.

      Publication Plan All research personnel listed on this protocol will be eligible for
      authorship in any resulting abstracts and publications in accordance with the qualifications
      outlined by the International Committee of Medical Journal Editors. The order of authors will
      be determined prior to manuscript development and depend on each individual's contribution to
      the study.

Open surgery and complex EVAR due to AAA

Comparison of Endovascular and Open Repair of Juxta- and Pararenal Abdominal Aortic Aneurysm on Short- and Long-term Clinical Outcomes

In open surgery this will include patients who were reoperated due to: graft infection, graft thrombosis, pseudoaneurysm formation, secondary AAA rupture. In endovascular group reintervention will include different reasons: endoleak, migration, thrombosis, infection, fracture, secondary AAA rupture.

Medical Doctor

This will include patients with all kinds of complications such as: surgical and non-surgical bleeding, wound infection, lower limb ischemia, mesenteric and colon ischemia, ileus, acute coronary syndrome, stroke/TIA, prolonged intubation (more than 72h), acute kidney injury (RIFFLE criteria), deep venous thrombosis, mortality, aortic-related reintervention

Patients undergoing open surgery due to juxta/pararenal abdominal aortic aneurysm

Patients undergoing some form of endovascular abdominal aortic aneurysm repair: fenestrated, chimney, etc.

Comparison of Outcomes of Complex Abdominal Aortic Aneurysm Treatment

About this trial

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Placebo

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