Maeda et al reported the Shaggy Aorta Scoring System to describe the appearance of the aorta not involved by aneurysm. The severity of changes in non-aneurysmal aorta impacts the risk of embolic complications. The authors are from the Jikei University in Tokyo.
Patient selection: aortic aneurysm, with thoracic endovascular aneurysm repair (TEVAR)
Outcome: embolic complications
Examination: CT angiography of the aorta with straight multiplanar reconstruction, with axial slices taken at 5 mm intervals
The aorta is divided into 3 zones:
(1) A1: from aortic valve to just after left subclavian artery
(2) A2: between A1 and A3
(3) A3: from just above celiac artery to iliac bifurcation
For each zone:
(1) determine total length in mm
(2) measure length of aneurysm
(3) residual aorta after removal of aneurysm is (total length) - (aneurysm length)
(4) number of slices to cover residual aorta is (residual length) / 5
(5) each slice is then scored based according to point assignment (below)
(6) the score for the zone is the sum of points for residual aorta
1 point was assigned for an axial slice with (presumably) all of the following:
(1) ulcer like thrombus
(2) maximal thrombus thickness >= 5 mm
(3) mural thrombus occupying more than two-thirds of the circumference of the aortic diameter
total score for entire residual aorta =
= (points for A1) + (points for A2) + (points for A3)
Interpretation:
• minimum score: 0
• maximum score: dependent on severity of atherosclerosis
• The higher the score the greater the risk of embolic complications.
• A patient with embolic complications has a worse prognosis.
• In patients without embolic complications the shaggy score was 2.0 +/- 5.3.
• In patients with embolic complications the shaggy score was 7.9 +/- 7.1.
Performance:
• The area under the ROC curve is 0.77.
