Management of Abdominal Aortic Aneurysm with Eccentric Thrombus

Initial Assessment and Imaging

The European Heart Journal recommends obtaining contrast-enhanced CT (CCT) as the optimal pre-operative imaging modality to assess the complete aorto-iliac system, measure true aneurysm diameter, and evaluate thrombus burden 1
CCT is mandatory for determining EVAR feasibility and sizing the aorto-iliac system for endovascular planning 1
The European Heart Journal suggests performing duplex ultrasound (DUS) of the femoro-popliteal segment since femoro-popliteal aneurysms commonly coexist with AAA 1

The European Heart Journal recommends surveillance intervals based solely on maximum aneurysm diameter, with AAA 45-50 mm (women) or 50-55 mm (men) requiring every 6 months with DUS 2, 3
For AAA 25-29 mm, every 4 years with DUS is recommended 3
For AAA 30-39 mm, every 3 years with DUS is recommended 3
For AAA 40-44 mm (women) or 40-49 mm (men), annual surveillance with DUS is recommended 3

The European Heart Journal recommends elective repair when AAA diameter reaches ≥55 mm in men or ≥50 mm in women, regardless of thrombus configuration 2, 1
Rapid growth ≥10 mm per year or ≥5 mm in 6 months is a trigger for intervention, even if below size threshold 1, 3
Saccular morphology ≥45 mm may be considered for repair due to higher rupture risk 1

The European Heart Journal suggests considering EVAR as preferred therapy based on shared decision-making for patients with suitable anatomy and reasonable life expectancy (>2 years) 1
EVAR reduces peri-operative mortality to <1% compared to open repair 1
In ruptured AAA with suitable anatomy, endovascular repair is recommended over open repair to reduce peri-operative morbidity and mortality 2, 1

The European Heart Journal recommends optimal cardiovascular risk management for all AAA patients to reduce major adverse cardiovascular events 2, 3
Avoiding fluoroquinolones unless compelling indication with no alternative is recommended 3

The European Heart Journal recommends 30-day imaging with CCT plus DUS/CEUS to assess intervention success 2, 1
Follow-up at 1 and 12 months post-operatively, then yearly until fifth post-operative year is recommended 2, 3
Re-intervene for type I or type III endoleaks to achieve seal 2, 1

Mural thrombus is associated with increased aneurysm expansion rates, and should be documented during imaging evaluation, according to the American College of Radiology 4, 5
Extensive mural thrombus (>90% circumference) in the proximal neck increases risk of type I endoleak and stent graft migration if endovascular repair is planned, as noted by the American College of Radiology 6
The presence of mural thrombus does not preclude endovascular repair, but rather affects technical considerations for the procedure, as stated by the American College of Radiology 6

Contrast-enhanced CT angiography (CTA) provides critical information about aneurysm size, thrombus presence, and dissection flap that determines intervention planning, according to the American College of Radiology 4
Multiplanar reformatted images with centerline 3-D software should be used to accurately measure diameter in tortuous aneurysms, as recommended by the American College of Radiology 4

Extensive mural thrombus covering >90% of proximal neck circumference warrants careful evaluation of EVAR feasibility due to increased endoleak and migration risk, as noted by the American College of Radiology 6
Open surgical repair remains appropriate for patients with unsuitable anatomy for EVAR or those with failed prior EVAR, according to the American College of Radiology 6

The European Society of Cardiology recommends that stent-graft diameter should be oversized by 10-20% relative to the aortic diameter at the proximal neck in patients with abdominal aortic aneurysm and mural thrombus 7, 8
Bifurcated stent-grafts are used in most cases of endovascular aneurysm repair for patients with abdominal aortic aneurysm and mural thrombus, as recommended by the European Heart Journal 7, 8
Fixation may be suprarenal or infrarenal depending on device and thrombus location in patients with abdominal aortic aneurysm and mural thrombus, according to the European Heart Journal 7, 8
Completion angiography must confirm absence of endoleak and patency of all components in patients with abdominal aortic aneurysm and mural thrombus undergoing endovascular aneurysm repair, as recommended by the European Heart Journal 7, 8

The European Society of Cardiology recommends re-intervention for type I or type III endoleaks to achieve seal in patients with abdominal aortic aneurysm and mural thrombus who have undergone endovascular aneurysm repair 7