There was no statistical difference (p<0,05) in linear parameters and volumes of aneurysmal sac comparing data from CTA and DSA (axial scans and 3D images).
But in 28,6% of cases involving CTA images,
aneurysmal neck wasn’t clearly visualized ( Fig. 4 ) and in 21,4% of cases it wasn’t visible efferents less than 1 mm in diameter originating from the aneurysmal sac.
( Fig. 5 ).
Statistically significant increases of aneurysmal sack volume up to 106,8% were revealed on DSA images ( Fig. 6 ).
Before embolization mean volume of aneurysms was 37 mm3 (21,5 mm3; 68,7 mm3),
after embolisation – 76,5 mm3 (55,4 mm3; 117,8 mm3).
Mean coil volume,
needed for total embolization,
was 17,5 mm3 (11,9 mm3; 26,2 mm3).
Mean embolization percentage (coils volume to aneurysm volume ratio) - 39,4% (24,1%; 53,2%).
For aneurusms less than 5 mm it was higher 50,6% (35%; 62,3%) than for aneurysm from 5 to 15 mm - 33,7% (22,8%; 50,6%) p=0,26.
Embolization percentage for aneurysms which were embolized with bare metal coils was 44,6% (23,4%; 67,9%), р=0.46,
and with for coils with hydrogel polymer coating - 35% (26,1%; 39,4%).
Also all patients were randomized by aspect-ratio (H/N) and dome to neck-ratio (D/N) indexes and embolization percentages were compared in these groups.
A point of division for aspect-ratio index was chosen 2 and dome to neck-ratio was 1.6.
It was estimated that aneurysms with greater D/N index needs less coils for total embolization aneurysmal sack – if D/N>1,6 embolization percentage was 29,9% (22%; 57,7%),
in the opposite group – 41,2% (35%; 50,6%),
р=0,6.
In the patient group with H/N>2 embolization percentage was 42,2% (24,4%; 67,9%) and for the opposite group - 35% (24,1%; 48,1%) correspondingly,
р=0,55 ( Fig. 7 ).
Mean angle between aneurysm long axis and parent vessel was 132,25±20° (chosen as a division point).
There was no influence on embolization percentage when compared two groups above and beyond this point (p<0,05).