Risk factors for spinal cord ischemia in frozen elephant trunk–induced upper spinal cord ischemia in patients with combination of degenerative arch aneurysms and peripheral artery diseases: a possible mechanism

The Cardiothoracic Surgeon

Table 4 Arterial calcification score and the number of collateral arteries

Variables	SCI (n=2) Patient A, B	No-SCI (n=12)
Arterial calcification score
Right SCA	1, 1	0.36±0.55 [0–2]
Left SCA	0, 1	0.68±0.67 [0–2]
Bilateral SCA	1, 2	1.04±1.05 [0–3]
Right HA	2, 1	1.48±0.94 [0–3]
Left HA	4, 1	1.56±1.13 [0–4]
Bilateral HA	6, 2	3.04±1.96 [0–6]
No. of collateral branches from HAs (range)
Right side	28, 45	16.5±4.4 [11–25]
Left side	38, 21	14.1±3.6 [10–23)
Total	66, 66	30.7±7.5 [21–47]
No. of patent SAs
Intercostal arteries (Th8–L2)	6, 6	6.0±0.0 [6]
Lumber arteries (L1–L5)	4, 5	3.66±1.97 [0–5]

The number of collateral branches of the hypogastric artery was greater in the SCI group than in the no-SCI group. There was no difference in the arterial calcification scores and the number of patent segmental arteries
Continuous data were presented as mean and standard deviation and categorical variables as numbers and percentages. The actual data for the two patients with spinal cord ischemia were presented
SCI spinal cord ischemia, SCA subclavian artery, HA hypogastric artery (internal iliac artery), SA segmental artery, NA not assessed