Natural Course of Dissecting Vertebrobasilar Artery Aneurysms without Stroke

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Fig 1.
3D-CTA reconstruction on the TeraRecon workstation and stretch view evaluating enlargement of the aneurysm diameter. Initial findings show a maximum diameter, 10.2 mm (A). Follow-up findings after 2 years show an increased maximum diameter, 12.2 mm (B). a, Volume rendering image (arrow indicates an aneurysm). b, Translucent image. c, MIP image of the stretch view. d, Calculated diameter.

Table 1:

Patient characteristics stratified by clinical presentation at diagnosis

	Group 1: Asymptomatic (n = 52)	Group 2: Pain (n = 56)	Group 3: Mass Effects (n = 5)	P Value
Age (yr) (mean) (SD)^{^a}	59.3 (9.4)	51.1 (10.6)	54.0 (11.7)	.0002^{^a}
Male (No.) (%)	38 (73.1)	44 (78.6)	4 (80.0)	.78^{^b}
Hypertension (No.) (%)	35 (67.3)	19 (33.9)	2 (40.0)	.002^{^b}
Diabetes (No.) (%)	1 (1.9)	5 (8.9)	0 (0.0)	.23^{^b}
Hyperlipidemia (No.) (%)	7 (13.5)	14 (25.0)	2 (40.0)	.18^{^b}
Current smoker (No.) (%)	24 (46.2)	26 (46.4)	1 (20.0)	.51^{^b}
Initial size of aneurysm (mean) (SD)^{^a}	7.7 (3.3)	7.2 (3.2)	10.2 (3.5)	.12^{^a}
Aneurysm location (No.) (%)				.70^{^b}
Left VA	18 (34.6)	25 (44.6)	1 (20.0)
Right VA	26 (50)	26 (46.4)	3 (60.0)
Bilateral VA	5 (9.6)	5 (8.9)	1 (20.0)
BA	2 (3.8)	0 (0.0)	0 (0.0)
Both VA and BA	1 (1.9)	0 (0.0)	0 (0.0)
Radiologic changes				<.001^{^b}
Improved (No.) (%)	1 (1.9)	15 (26.8)	1 (20.0)	<.001^{^c}
Unchanged (No.) (%)	50 (96.2)	38 (67.9)	3 (60.0)	<.001^{^d}
Enlarged (No.) (%)	1 (1.9)	3 (5.4)	1 (20.0)	.15^{^e}
Clinical course				.048^{^f}
Stable (No.) (%)	51 (98.1)	55 (98.2)	4 (80.0)
Deteriorated (No.) (%)	1 (1.9)	1 (1.8)	1 (20.0)

Note:—VA indicates vertebral artery; BA, basilar artery.
↵a P value was calculated by analysis of variance.
↵b P value was calculated by the χ² test.
↵c P value was calculated by the χ² test between improved or not improved.
↵d P value was calculated by the χ² test between unchanged or changed, either improved or enlarged.
↵e P value was calculated by the χ² test between enlarged or not enlarged.
↵f P value was calculated by the χ² test between clinically stable or deteriorated.

Table 2:

Cases with radiologic and clinical deterioration

Patient No. (age [yr])/sex)	Initial Size (mm)	Maximum Size (mm)	Follow-Up Period (mo)	Clinical Deterioration	Treatment
48/M	21.2	27.5	91.1	Cerebellar ataxia	Endovascular trapping
59/F	17.7	25.9	19.2	Cerebellar ataxia, dysphagia	Endovascular trapping
43/F	16.1	18.3	20.4	Wallenberg syndrome, SAH	Endovascular trapping
35/M	9.1	12.3	35.4	None	Stent-assisted coiling
48/M	10.1	12	8.3	None	Stent-assisted coiling

Table 3:

Cox proportional hazards model to find factors associated with aneurysm reduction

	Single Cox Proportional Hazards Model			Multiple Cox Proportional Hazards Model^{^a}
	Hazard Ratio	95% CI	P Value	Hazard Ratio	95% CI	P Value
Age (yr)	0.93	0.89–0.98	.003	0.99	0.93–1.05	.63
Male sex	0.68	0.25–1.86	.46
Clinical presentation at diagnosis
Asymptomatic	Reference	–	–	Reference	–	–
Pain	14.7	1.94–111	.009	3.63	0.38–34.8	.26
Mass effect	7.94	0.50–127	.14	13.3	0.59–299	.10
Size
Maximum diameter (mm)	0.61	0.46–0.82	.001	0.58	0.41–0.84	.004
≥10 mm	0.29	0.04–2.26	.24
Hypertension	0.08	0.02–0.35	.001	0.12	0.02–0.70	.018
Diabetes^{^b}
Hyperlipidemia	0.47	0.11–2.08	.32
Smoking	0.78	0.29–2.13	.63
Location
Left	1.39	0.16–12.5	.77
Right	2.87	0.37–22.1	.31
Bilateral	Reference

Note:—CI indicates confidence interval.
↵a Variables that were statistically significant in single Cox proportional hazards models were used in the multiple Cox proportional hazards models. The cutoff point of the P value was set at <.05.
↵b All 6 patients with diabetes were excluded from this analysis because their aneurysms were unchanged.

Table 4:

Cox proportional hazards model to find factors associated with aneurysm enlargement

	Single Cox Proportional Hazards Model
	Hazard Ratio	95% CI	P Value
Age (yr)	0.93	0.85–1.01	.086
Male sex	0.54	0.09–3.22	.50
Clinical presentation at diagnosis
Asymptomatic	Reference	–	–
Pain	2.83	0.29–27.3	.37
Mass effect	9.38	0.56–156	.12
Size
Maximum diameter (mm)	1.30	1.11–1.52	.001
≥10 mm	18.0	1.95–167	.011
Hypertension	0.38	0.06–2.34	.30
Diabetes^{^a}
Hyperlipidemia	0.88	0.10–7.92	.91
Smoking	0.85	0.14–5.10	.86
Location
Left	0.13	0.01–1.65	.12
Right	0.19	0.02–1.57	.12
Bilateral	Reference