ShOrt neCK AAA RAndomized Trial - ESAR and FEVAR: SOCRATES
Physician-Initiated Trial Investigating ESAR (EVAR Plus Heli-FX EndoAnchors) and FEVAR for the Treatment of Aortic Aneurysms With Short Infrarenal Aortic Neck

Abdominal aortic aneurysms (AAA) with a short and hostile infrarenal neck
present higher risk independently from the technique used to treat them. The
morbidity and mortality after open surgery is high, especially in multimorbid
subjects (13, 14). Suprarenal or supravisceral clamping increased the risk of
renal function deterioration and cardiac failure.
Over the years, many different techniques have been used to manage AAA with
hostile proximal neck, including FEVAR (Fenestrated endovascular aortic repair)
and ESAR (endosuture aortic repair). However, for FEVAR renal catheterization
and stenting are required, and the procedure is technically demanding with high
radiation exposure and contrast media use. Additionally, FEVAR procedures
require custom made devices which increases case planning complexity and are
technically demanding. The postoperative mortality is low, but during the
follow up there is a risk of loss of target vessel patency with consequent
renal or mesenteric ischemia. ESAR consisting of standard EVAR in combination
with EndoAnchors evolved as an endovascular alternative to open surgery or
FEVAR for aneurysm with short and hostile necks. The rationale of this method
is to improve fixation of the endograft using the Heli-FX EndoAnchor System.
Mimicking the security of a hand-sewn aortic anastomosis, EndoAnchors are
intended to provide fixation and sealing between endovascular grafts and the
native aortic wall at the level of the proximal attachment site, with good
assistance in the prevention and management of type Ia endoleaks and
stent-graft migration in patients with challenging aortic necks. Compared to
FEVAR, ESAR does not require devices customized to a specific subject's anatomy
and is a less technically demanding procedure reducing radiation exposure and
contrast medium load. Additionally, the technique does not require cannuation
and stenting of the renal and visceral arteries. This technique is technically
easier and can be adopted also by centers not familiar with renal artery
catheterization and stenting. The risk of stent-related complications
(thrombosis, instent restenosis, fractures, secondary procedures) is also lower.

Studies showed that the Endurant II/IIs endograft in conjunction with Heli-FX
EndoAnchor implants appear to be a safe and effective treatment option with
procedural success rate of 97.1% and technical success rate of 88.6%.
However, to date, there is no head-to-head comparison between the FEVAR and the
ESAR treatment options for AAA with short and hostile infrarenal necks.

The aim of this randomized study is to compare the safety and performance of
EndoVascular Aneurysm Repair with ESAR using Endurant + Heli-FX EndoAnchor and
FEVAR using customizable grafts from Cook (Zenith Fenestrated Graft) and Terumo
(Fenestrated Anaconda Graft) for the treatment of aortic aneurysms with short
aortic neck (4 to 15mm). Both techniques and medical devices are currently
being used as standard of care in the treatment of abdominal aortic aneurysm.

Investigator-initiated, prospective, interventional, multi-center, randomized
(1:1), two-arm, open-label, non-inferiority postmarket study

The study will enroll at least 204 subjects randomized 1:1 to ESAR or FEVAR
procedure .

This study will utilize the CE marked/PMA approved Medtronic Endurant II/IIs
Stent Graft Systems in combination with Medtronic Heli-FX EndoAnchor system for
the ESAR procedures. For FEVAR procedures, this study will utilize CE
marked/PMA approved and/or custom made commercially available Cook Zenith
Fenestrated or Terumo Fenestrated Anaconda stent graft systems. All devices
will be used within intended use as described in the approved Instructions for
Use (IFU) for which CE mark/PMA approval has been obtained.

Group 1: ESAR procedure: Endovascular Aneurysm Repair (endograft) + Heli-FX
EndoAnchors
Medical devices used: Medtronic Endurant II and Endurant IIs Stent Graft
Systems with Heli-FX EndoAnchor system

Group 2: FEVAR procedure: Fenestrated EndoVascular Aneurysm Repair (fenestrated
endograft)
Medical devices used: Cook Zenith Fenestrated of Terumo Fenestrated Anaconda
stent graft systems

A more detailed description of both techniques used:
Endovascular aortic repair (EVAR) is a minimally invasive procedure by using a
stent to repair aortic aneurysms and dissections that occur in the abdominal
aorta. The fenestrated endograft is inserted into the femoral artery via an
incision in the groin percutaneously, or through the skin. It is then guided
through the blood vessel to the aneurysm. Advantages of endovascular treatment
of complex aneurysmas are: less invasive surgery, shorter hospitalization time
and less scar tissue. Disadvantages are: annual control visits and use of
radiation and contrast medium.

FEVAR technique: Traditional EVAR works when aneurysms are located far enough
from the renal (kidney) arteries, which branch off the aorta, that the stent
can be securely attached to the aorta. However, for approximately 10 percent of
patients with an abdominal aortic aneurysm, the aneurysm is too close to the
arteries that branch off to the kidneys for traditional EVAR to work. The
location of this aneurysm is complicated to treat and often requires open
surgery to repair the weakened wall. Until recently, the only option these
patients had was major abdominal surgery or no surgery at all. The unique
feature of fenestrated endografts (FEVAR) is that they can cover branch
arteries of the aorta (such as the renal arteries) because the graft has
fenestrations, or holes, that correspond to the position of the branching
arteries within the aorta to allow for blood to flow through the graft into the
branch vessel. This FEVAR procedure will be applied in one of the 2 study
groups. FEVAR procedures often require custom made devices and are technically
demanding. the production takes 8-12 weeks. In some cases its remains
impossible to produce a stent that fits due to anatomical or technical reasons.

ESAR technique: ESAR uses standard (non-fenestrated) endografts or stents in
combination with a Heli-FX* EndoAnchor* system from Medtronic, which improve
fixation of the endograft to the aortic wall thereby reducing the risk f stent
migrationand endoleaks. This technique will be applied in the other study
group.

Patients will be randomized to a 'standard of care' treatment (FEVAR or ESAR)
and will undergo the same treatment as those who does not participate in this
study. After 1, 12, 24 and 36 months a CT angiography will be performed to
follow up the result of the procedure which is not different from the follow-up
protocol of patients undergoing ESAR or FEVAR not participating in this trial.
As such, the patient will not be exposed to additional radiation by
participating in this trial. For patients with renal insufficiency during
follow-up who should not be given contrast medium will have an MRI or a CT
without contrast with duplex ultrasound imaging, in order to monitor the stent
and the aneurysm.

The risks listed below are thus inherent to the 'standard of care' treatment
for this patient population.
During ESAR or FEVAR procedures a vessel or the aorta can be injured
(perforation or dissection), or embolization can occur. Based on the
literature, these findings occur in <1% of subjects. During FEVAR procedure,
occlusion of the BSG (Bridging Stent Graft) can lead to organ ischemia, which
can lead to death in a worst-case scenario. During FEVAR, occlusion of the
renal artery can lead to renal function impairment and dialysis if left
untreated.
In both ESAR and FEVAR procedures, endoleaks could lead to aneurysm sac
enlargement and eventually rupture. These are expected to be found in <3% of
subjects and should be treated accordingly to avoid further sac enlargement.

The use of both ESAR and FEVAR procedures is a safe and effective technique.
All study products are CE marked/PMA approved and/or custom made and will be
used according to their applicable IFUs. Furthermore, the indications and
contraindications are provided in the instructions for use of the respective
devices. For a complete list of possible risks we refer to the IFU of the
medical devices used in the trials:

ESAR procedure: Medtronic Endurant II/IIs Stent Graft Systems in combination
with Medtronic Heli-FX EndoAnchor system
FEVAR procedure: Cook Zenith Fenestrated or Terumo Fenestrated Anaconda stent
graft systems