ARTERIAL DILATIVE

Inclusion Criteria for FEVAR

• Juxta- or pararenal aneurysm (thoracoabdominal aneurysms are not treated at our center)
• Infrarenal neck of at least 4 mm
• Patent ostia of renal arteries (4-8 mm), SMA, and celiac trunk (6-10 mm)
• ZFEN requires at least 15 mm proximal sealing zone – small fenestration
• >12 mm from the proximal edge and necessary SMA scallop
• Supra- and/or infrarenal angulation <45 degrees
• Iliac diameter ≥9 mm ipsilateral, ≥7 mm contralateral

• Multiple small renal arteries or early bifurcation of the renal artery
• Severe angulation (> 45 degrees)
• Shaggy aorta
• Inadequate access (minimum 7-8 mm)

Consider planning proximal sealing further upstream if it does not lead to overstenting of extra-lumbar/intercostal arteries, improving long-term outcomes.

A CTA thorax-abdomen must be performed. If only a CTA abdomen is available, an additional CTA thorax (including proximal carotid and left subclavian artery imaging) is required.
Length measurements:

• Proximal – center of each visceral branch
• Proximal – aortoiliac bifurcation
• Proximal – iliac bifurcation
• Landing zone length for target vessels

• Aorta (proximal, at fenestrations, aortoiliac bifurcation)
• Visceral target vessels
• Iliac and femoral access
• Diameter of IMA and lumbar arteries to be overstented

• Each visceral origin
• Lumbar arteries

• Adequate proximal sealing – if it does not require overstenting extra-lumbar arteries, consider extending the sealing zone proximally.
• 4-fenestration vs. 2-fenestration configurations: Longer, healthy sealing zones improve long-term outcomes. If disease progression occurs, there is a risk of stent migration and kinking in target vessels.
• Avoid brachial access if possible (higher complication risk and increased radiation exposure for the operator).

• Discontinue clopidogrel perioperatively and switch to aspirin in case spinal drainage is required.
• Ensure 2 cross-matched blood units are available.
• Confirm sedation team availability.
• Hemoglobin >6 mmol/L – correct if lower.
• Patient admission fasting on the day of surgery.
• Antibiotic prophylaxis: Cefazolin 2000 mg IV once, repeat 1000 mg if procedure >4 hours, continue for 24 hours (3x 1000 mg/day).
• Urinary catheter placement.
• No prophylactic cerebrospinal fluid drainage.
• Monitor connection (ECG, BP).
• Ensure two functional IV lines
• 2000 mg Kefzol

• Check anticoagulation
• Check allergies
• Imaging and EVAR measurement on wall/monitor
• Check ordered grafts tents

• Chlorhexidine
• Standard angiography set
• Lidocaine 10 ml x 2
• Bupivacaine 10 ml x 2
• Contrast
• Heparinized saline and flushing syringes
• 6F Introducer x 2

• Terumo wire 260
• 2x Lunderquist 260
• Rosen wire per renal artery
• Amplatz short DP for SMA/celiac trunk

• 7F, 55 cm (1 per fenestration)
• 20F guiding sheath (for 7F sheaths to pass through)
• Use 22F for 4-fenestration cases

• CODA balloon
• PTA balloon (flare balloon)

• ZFER
• Zenith Flex bifurcation
• Ipsilateral and contralateral leg components

• Manta 14F (up to 14F)
• Manta 18F (15-20F)

• Supine position, arms behind the head or alongside the body (2 fenestrations).
• Skin disinfection and exposure of the groin, abdomen from xiphoid to symphysis, and axillary/brachial region.
• Anesthesia position: head end on the right side.
• C-arm and monitor position: left side of the patient.
• Team position: right side of the patient (assistant may be opposite the operator).

Preparation

• TOP
• Antibiotics
• Imaging and EVAR measurements on the monitor
• Check prostheses
• Position the patient: table cranially, left arm alongside the body, peripheral pulses
• Drape according to protocol
• Pressure line to syringe pump and flush

• Local anesthesia in the groin
• Ultrasound-guided puncture of the CFA, measure for Manta closure device and place 7Fr sheaths
• 5000 IU heparin, repeat 2500 IU every hour

• Insert stiff guidewire via Terumo/angiocatheter on the main side
• Check markers outside the patient

• Insert fenestrated endoprosthesis (ZFEN) ipsilaterally
• Perform angiography to visualize renal arteries from the contralateral side
• Check markers (in AP position, optionally cranio-caudal, proximal, fenestrations, anterior/posterior, tick marker, and distal) (Figure 3)
• Partially deploy ZFEN to "diamond shape" and check fenestrations, then continue deployment

• Engage the prosthesis from the left, insert Terumo guidewire with catheter into the graft
• Exchange catheter over stiff guidewire for a 20F sheath within the graft
• Puncture this sheath (eccentrically) and insert two short 7F sheaths
• Engage renal artery with Terumo/catheter (e.g., Berenstein), place Rosen wire via the catheter
• Advance a long 7F sheath (ANL) over it
• Engage the other renal artery
• Replace short sheath and catheter on this side as well with a long 7F sheath into the renal artery
• Advance stents into the renal arteries via the 7Fr sheaths
• Fully deploy ZFEN (reducing ties) and top stent after retracting angiocatheter
• Release stent from delivery device and retrieve top cap
• Balloon dilation with Coda balloon
• Align renal artery (markers in line) and retract 7Fr sheath
• Place stents in the sheaths, then retract the sheaths
• Deploy stent and flare with tip PTA balloon (10 or 12 mm)
• Repeat for the other renal artery
• Reintroduce sheaths into renal arteries and perform bilateral angiography with apnea; check aneurysm filling from renal arteries
• Remove both renal artery guidewires and 7F sheaths

• Replace main sheath with bifurcation prosthesis
• Maximum proximal marker height just below the bifurcation
• Deploy with contralateral limb above aortic bifurcation
• Engage contralateral limb and open the top of the bifurcation
• Insert Lunderquist
• Place contralateral limb according to standard EVAR procedure
• Complete ipsilateral limb and remove delivery device according to standard EVAR procedure
• Withdraw sheaths distally to the CIA bilaterally and perform ballooning (cuff overlap, not above bifurcation, and CIA bilaterally)

• Perform control angiogram, long series, to assess potential endoleak and patency of renal arteries and CIAs

• Remove devices/sheaths/catheters
• Hemostasis with Manta device bilaterally
• SOP

• When attaching the limb, it is possible to catheterize the cuff instead of the limb. To check this, place the catheter high in the roof of the bifurcated graft (which is still "closed"). If the catheter then bends back, it indicates that you are in the limb. An additional check is that when pulling back the black trigger wire, the catheter "pops" up.
• If you are still unsure, you can insert a Coda balloon and inflate it proximally in the limb, creating a "mushroom" shape.

Spinal Cord Ischemia (SCI)
A serious but uncommon complication after FEVAR (<2%). The risk increases when a larger portion of the aorta is covered (including lumbar and intercostal arteries), after previous aortic surgery, or in cases of occlusion of important collateral arteries supplying the spinal cord, such as the left subclavian artery and the internal iliac arteries. Significant blood loss is also a risk factor for SCI. In a large series of over 200 patients, no cases of SCI were observed in patients with a sealing zone <4 cm proximal to the celiac trunk (Juszczak 2019).

Management of SCI (Scali 2018):

• Transfer the patient to ICU/MC
• Target blood pressure: MAP 90–100 mmHg
• Initiate spinal fluid drainage (<1 hour; see below)
• Target hemoglobin >6 g/dL
• Methylprednisolone (hydrocortisone/dexamethasone also acceptable?) 1000 mg IV over 30 minutes (to reduce edema)
• Mannitol 12.5 g IV over 15 minutes
• Naloxone 1–1.5 mcg/kg/hour IV
• Avoid morphine (due to spinal cord metabolism), use fentanyl if pain relief is needed
• Involve ICU neurology team

• Draining spinal fluid lowers resistance to spinal cord perfusion according to the formula:
• Spinal Cord Perfusion Pressure = Blood Pressure – Cerebrospinal Fluid Pressure**
• In other words, by reducing cerebrospinal fluid pressure, spinal cord perfusion improves (see Figure 4).

• Insert a spinal drain using a 16G Tuohy needle
• Set the drain at 10 cm H₂O after placement
• If symptoms persist, lower to 5 mmHg (caution: do not drain more than 30 mL/hour)
• Warning: Rapid or excessive drainage may rupture anchoring veins, causing severe intracerebral hemorrhage
• Strict bed rest, avoid elevating the head to prevent increased drainage
• Check drain positioning every 4 hours
• If headache occurs, reduce drainage if the neurological status allows
• Keep the drain in place for 48 hours, then remove unless symptoms reappear after closure
• If bloody fluid drains, stop drainage temporarily, consult neurology, and perform CT brain or MRI myelography to rule out bleeding

• Complications include subarachnoid hemorrhage (SAH), spinal hematoma, stroke (bleeding), paresthesia during drainage, reflex hypotension, bloody cerebrospinal fluid, drain dysfunction, or infection. Prophylactic drainage is generally not performed except in high-risk patients, such as those with:
• Thoracic stenting >200 mm
• Stenting at T8–T12
• Extensive previous abdominal aortic surgery or TEVAR
• Chronic kidney failure, anemia, or perioperative MAP <70 mmHg, which may also contribute to spinal ischemia

• Suspected visceral stent occlusion → Urgent CT-Angio and consult vascular surgery
• Endoleak around fenestrations (Type 3) → Reintervention to restore seal
• Other complications** similar to standard EVAR (see AAA – Endovascular Treatment (EVAR))

Day of Procedure:

• Postoperative observation in IC/MC
• Hourly neurological checks of the legs (lifting both legs off the bed)
• Target systolic BP: 120–150 mmHg (MAP >80)
• Puncture sites covered with dressings
• 4 hours of bed rest (due to closure device), avoiding hip, abdominal, and neck flexion to prevent pressure on the groin
• Extended bed rest and SPICA dressing if indicated (e.g., minor ongoing bleeding despite proper closure device use)
• Early mobilization after initial short immobilization
• Unrestricted diet, IV fluids as needed

• Check groins for swelling and pulsations
• Lab tests: Hb, Creatinine
• Discharge if no complications

Pre-Discharge and Follow-Up Plan

• Pre-discharge CTA (CT angiography)
• 6-week follow-up with the operating surgeon, including a CTA, to be discussed in the vascular meeting
• Annual follow-up CTA

• Type 1 or 3 endoleak on first postoperative CTA → Refer to vascular meeting and plan reintervention
• Type 2 endoleak without aneurysm growth → Conservative management
• Type 2 endoleak with aneurysm growth (≥5 mm in 1 year) → Refer to vascular meeting and plan reintervention
• Target vessel occlusion or stenosis → Refer to vascular meeting

• Verify if the patient is on antiplatelet therapy or anticoagulation and a statin
• If not prescribed, initiate:
• Clopidogrel 75 mg once daily
• Atorvastatin 40 mg once daily