Morphological Irregularity of Unruptured Intracranial Aneurysms is More Related with Aneurysm Size Rather Than Cerebrovascular Atherosclerosis: A Case-Control Study

Figures & data

Table 1 Distribution of Age, Sex and Locations of Cases and Controls

Characteristics	Cases	Controls
Number	140	140
Female, n(%)	93(52.0%)	86(48.0%)
Male, n(%)	47(46.5%)	54(53.5%)
Rupture aneurysm	37(26.4%)	50(35.7%)
Age(years)
Mean ± SD	60.2±12.4	59.0±10.2
< 50	25(17.9%)	25(19.9%)
50–70	92(65.7%)	92(65.7%)
≥70	23(16.4%)	23(16.4%)
Locations of aneurysms, n(%)
ICA	43(30.7%)	43(30.7%)
ACOM	23(16.4%)	23(16.4%)
PCOM	32(22.9%)	32(22.9%)
ACA	2(1.4%)	2(1.4%)
MCA	22(15.7%)	22(15.7%)
PC	18(12.9%)	18(12.9%)

Abbreviations: SD, standard deviation; PCOM, internal carotid-posterior communicating artery; ACOM, anterior communicating artery; MCA, middle cerebral artery; ICA, internal carotid artery; PC, basilar tip and basilar-superior cerebellar artery and vertebral artery-posterior inferior cerebellar artery and vertebrobasilar junction; ACA, anterior cerebral artery.

Table 2 Distribution of Age, Sex and Locations of Cases and Controls in Unruptured IAs

Characteristics	Cases	Controls
Number	89	89
Female, n(%)	57(64.0%)	51(57.3%))
Age(years)
Mean ± SD	59.8±11.7	60.2±12.4
< 50	15(16.9%)	15(16.9%)
50–70	61(68.5%)	61(68.5%)
≥70	13(14.6%)	13(14.6%)
Locations of aneurysms, n(%)
ICA	31(34.8%)	31(34.8%)
ACOM	15(16.9%)	15(16.9%)
PCOM	18(20.2%)	18(20.2%)
ACA	1(1.1%)	1(1.1%)
MCA	13(14.6%)	13(14.6%)
PC	11(12.4%)	11(12.4%)

Table 3 Frequency and Odds of Vascular Risk Factors in Cases Compared to Controls

Characteristics	Controls	Cases	P-value	OR (95% CI)
Number	140	140
Smoking status
Nonsmoker	115(82.1%)	106(75.7%)	Reference	Reference
Former smokers	22(15.7%)	30(25.4%)	0.564	1.4(0.5–4.1)
Current smokers	3(2.1%)	4(2.9%)	0.7	0.7(0.3–6.5)
Alcohol use	11(8.0%)	19(13.5%)	0.117	1.9(0.8–4.1)
Hypertension	91(65.0%)	93 (66.4%)	0.801	1.1(0.7–1.7)
Hyperlipidemia	27(19.3%)	34(24.3%)	0.311	1.3(0.2–2.4)
Diabetes mellitus	12(8.1%)	14(10.0%)	0.680	1.2(0.5–2.7)
Cerebral ischemic comorbidities	23(16.4%)	24(17.3%)	0.852	1.1(0.6–2.0)
Cardiac comorbidities	18(13.2%)	12(8.7%)	0.229	0.6(0.3–1.4)
Previous SAH	9(6.4%)	6(4.3%)	0.426	0.7(0.2–1.9)
Multiplicity	84(60.0%)	68(48.6%)	0.055	0.6(0.4–1.0)
Aneurysm size≥7mm	25(17.9%)	51(36.4%)	<0.001	1.5(1.1–2.2)
Bifurcation	79(56.4%)	93(66.4%)	0.086	1.5(0.9–2.5)
Cerebrovascular stenosis stenosis, n(%)	20(9.4%)	12(8.7%)	0.799	1.1(0.5–2.3)
No or less than 50%	107(76.4%)	102(72.9%)	Reference	Reference
50–70%	16(11.4%)	18(12.9%)	0.750	1.1(0.7–1.8)
≥ 70%	17(12.1%)	20(14.3%)	0.676	1.1(0.7–1.8)
Parent artery stenosis
No or less than 50%	129(92.1%)	124(88.6%)	Reference	Reference
50–70%	6(4.3%)	9 (6.4%)	0.509	1.5(0.5–4.8)
≥ 70%	5(3.6%)	7(5.0%)	0.086	2.5(0.9–7.0)
Number of stenosis cerebral arteries artecerebralvascular
No or less than 50%	107(76.4%)	102(72.9%)	Reference	Reference
Single	24(17.1%)	20(14.3%)	0.771	0.9(0.6–1.5)
Multiple	9(6.4%)	18(12.9%)	0.222	1.4(0.8–2.3)
Location of cerebralvascular stenosis
No or less than 50%	107(76.4%)	102(72.9%)	Reference	Reference
Anterior circulation	16(11.4%)	16(11.4)	0.928	1.0(0.6–1.7)
Posterior circulation	10(7.1%)	10(7.1%)	0.942	1.0(0.5–2.0)
Anterior and Posterior circulation	7(5.0%)	12(8.6%)	0.398	1.3(0.7–2.4)

Notes: ORs show results of Cochran-Mantel-Haenszel test for cases vs controls or unadjusted conditional logistic regression results. The P-values are results of Pearson chi-square tests.

Abbreviation: OR, odds ratio.

Figure 1 The distribution of the severity of atherosclerosis stenosis in the irregular and regular groups.

Figure 2 The distribution of number of arteries with stenosis, and location of the stenosis in the irregular and regular groups.

Figure 3 The distribution of location of the stenosis in the irregular and regular groups.

Table 4 Frequency and Odds of Vascular Risk Factors in Cases Compared to Controls in Unruptured IAs

Characteristics	Controls	Cases	P-value	OR (95% CI)
Number	89	89
Smoking status
Nonsmoker	115(82.1%)	106(75.7%)	Reference	Reference
Former smokers	22(15.7%)	30(25.4%)	0.770	0.9(0.6–1.4)
Current smokers	3(2.1%)	4(2.9%)	0.704	1.1(0.7–1.7)
Alcohol use	6(6.7%)	12(13.4%)	0.136	2.2(0.8–6.0)
Hypertension	91(65.0%)	93 (66.4%)	0.630	1.2(0.6–2.2)
Hyperlipidemia	21(23.6%)	28(31.5%)	0.240	1.5(0.8–2.9)
Diabetes mellitus	9(9.1%)	13(14.6%)	0.362	1.5(0.6–3.8)
Cerebral ischemic comorbidities	19(21.3%)	11(12.5%)	0.117	0.6(0.2–1.2)
Cardiac comorbidities	18(13.2%)	12(8.7%)	0.229	0.6(0.3–1.4)
Previous SAH	6(6.7%)	4(4.5%)	0.515	0.7(0.2–2.4)
Multiplicity	54(60.7%)	44(49.4%)	0.132	0.6(0.4–1.1)
Aneurysm size≥7mm	15(16.9%)	38(42.7%)	<0.001	3.7(1.8–7.4)
Bifurcation	47(52.8%)	55(61.8%)	0.225	1.4(0.8–2.6)
Cerebralvascular stenosis stenosis, n(%)	20(9.4%)	12(8.7%)	0.799	1.1(0.5–2.3)
No or less than 50%	71(79.8%)	63(70.8%)	Reference	Reference
50–70%	4(4.5%)	12 (13.5%)	0.750	1.1(0.7–1.8)
≥ 70%	12(15.7%)	12(15.7%)	0.676	1.1(0.7–1.8)
Parent artery stenosis
No or less than 50%	85(95.5%)	78(87.6%)	Reference	Reference
50–70%	3(3.6%)	6 (6.7%)	0.434	1.4(0.6–3.2)
≥ 70%	1(1.1%)	5(5.6%)	0.229	1.7 (0.7–4.3)
Number of stenosis cerebral arteries artecerebralvascular
No or less than 50%	71(79.8%)	63(70.8%)	Reference	Reference
Single	10(11.2%)	11 (12.4%)	0.741	1.1(0.6–2.1)
Multiple	8(9.0%)	15(16.9%)	0.255	1.4(0.8–2.4)
Location of cerebrovascular stenosis
No or less than 50%	71(79.8%)	63(70.8%)	reference	reference
Anterior circulation	6(6.7%)	9(7.9%)	0.494	1.3(0.6–2.6)
Posterior circulation	6(6.7%)	7(10.1%)	0.733	1.1(0.5–2.5)
Anterior and Posterior circulation	6(6.7%)	10(11.2%)	0.403	1.3(0.7–2.6)

Notes: ORs show results of Cochran-Mantel-Haenszel test for cases vs controls or unadjusted conditional logistic regression results. The P-values are results of Pearson chi-square tests.

Abbreviation: OR, odds ratio.

Figure 4 (A) A 49-year-old female was found to have an intracranial aneurysm located in the left internal carotid artery. No obvious stenosis was found in parent artery. The diameter of the aneurysm was more than 7 mm, and the aneurysm was found to be irregular in shape with daughter sac. (B) A 60-year-old man was found to have an intracranial aneurysm located in the left internal carotid artery. The parent artery had obvious stenosis. The diameter of the aneurysm was more than 7 mm. It was found that the aneurysm was irregular in shape with daughter sac.