A comparative study of 43 patients with mirror-like intracranial aneurysms: risk factors, treatment, and prognosis

Figures & data

Table 1 Demographic characteristics according to the type of intracranial aneurysm

Characteristic		MirAn, n (%)	nMirAn, n (%)	SingAn, n (%)	P-value
Sex	M	7 (16.3)	24 (34.3)	561 (43.9)	0.0005*
	F	36 (83.7)	46 (65.7)	717 (56.1)
	M:F	1:5.1	1:1.9	1:1.3
Age (years), mean ± SD		51.4±9.2	51.3±9.9	46.7±11.5	0.0002*
Age groups	<30	0	0	98 (7.7)	0.0022*
	30–39	7 (16.3)	9 (12.9)	208 (16.3)
	40–49	10 (23.3)	17 (24.3)	442 (34.6)
	50–59	16 (37.2)	32 (45.7)	363 (28.4)
	≥60	10 (23.2)	12 (17.1)	167 (13.1)
Marfan syndrome		0	0	1 (0.07)
Presentation	SAH	40 (93.0)	58 (80.0)	1,203 (89.2)
	Neurologic symptoms#	3 (7.0)	8 (11.4)	68 (5.3)
	Incidental finding	0	6 (8.6)	7 (5.5)

Notes:

* Significant difference, P<0.05.

# Including oculomotor nerve palsy, diminution of vision, and visual field defect.

Abbreviations: MirAn, mirror-like intracranial aneurysms; nMirAn, non-mirror-like multiple aneurysms; SingAn, single aneurysms; M, male; F, female; SAH, subarachnoid hemorrhage; SD, standard deviation.

Figure 1 Relative prevalence of risk factors by age. (A) In patients with MirAn. (B) In nMirAn patients.

Note: Smoking refers to cigarette smoking.
Abbreviations: HBP, high blood pressure; MirAn, mirror-like intracranial aneurysms; nMirAn, non-mirror-like multiple aneurysms; NRF, no known extrinsic risk factors.

Table 2 Hunt and Hess grade and aneurysm sites in patients with SAH

Clinical feature	N (%)
Patients with SAH	40 (100)
Hunt and Hess grade, n (%)
I	19 (44.2)
II	12 (27.9)
III	6 (14)
IV	3 (7)
Ruptured aneurysms, n (%)
One	35 (81.4)
Two	5* (11.16)
Aneurysm site, n (%)
Undetermined	1 (2.5)
Left hemisphere	20 (50)
Right hemisphere	18 (45)
Both hemispheres	1 (2.5)
Artery, n (%)
Posterior communicating arteries	26 (65.0)
Artery bifurcations	14 (35.0)

Notes:

* In four of these patients, the rupture occurred again because they refused to undergo operation or interventional therapy. The fifth patient underwent open surgery after the first rupture of the left posterior communicating aneurysm, but refused to undergo surgery for the contralateral aneurysm; therefore, the right-side aneurysm ruptured and the patient underwent another surgery.

Abbreviation: SAH, subarachnoid hemorrhage.

Figure 2 DSA images of both the left and right internal carotid arteries before clipping. DSA suggests that the aneurysms arise from the branches of the bilateral middle cerebral artery (indicated by arrow).

Notes: (A) Right internal carotid artery (normal position); (B) right internal carotid artery (lateral position); (C) left internal carotid artery (normal position); (D) left internal carotid artery (lateral position).
Abbreviation: DSA, digital subtraction angiography.

Figure 3 DSA images of the left and right internal carotid arteries after clipping. Both aneurysms from the bilateral middle cerebral artery branches are completely occluded (normal position, indicated by the arrow).

Notes: (A) Left aneurysms; (B) right aneurysms.
Abbreviation: DSA, digital subtraction angiography.

Table 3 Treatment and follow-up for the patients with MirAn

Treatment or follow-up	Patients with MirAn, n (%) N=43
Total number of patients treated	43 (100)
Aneurysmal clipping	39 (90.7)
Embolization	4 (9.3)
Additional intervention via aneurysmal clipping	19 (44.2)
Follow-up and further assessment	39 (90.7)

Abbreviation: MirAn, mirror-like intracranial aneurysms.