Risk factors for growth of unruptured intracranial aneurysms: follow-up study by serial 0.5-T magnetic resonance angiography.

OBJECTIVE

The independent risk factors for aneurysm growth were retrospectively investigated in 130 patients with unruptured aneurysms who were followed up by 0.5-T serial magnetic resonance angiography with stereoscopic images.

METHODS

Age, sex, site of aneurysm, size of aneurysm, multiplicity of aneurysms, type of circle of Willis, length of follow-up period, cerebrovascular event, hypertension, diabetes, hyperlipidemia, smoking habit, and family history of subarachnoid hemorrhage were investigated using multiple logistic analysis.

RESULTS

Fourteen patients (16 aneurysms) among the 130 patients (159 aneurysms) showed aneurysm growth (10.8%) during follow-up of 10 to 69 months (mean 29.3 +/- 10.5 mo). Multiple logistic analysis disclosed that location on the middle cerebral artery (odds ratio [OR] 0.08, P < 0.01), multiplicity of aneurysms (OR 68.5, P < 0.01), aneurysm size of 5 mm or larger (OR 1.17, P = 0.05), and family history of subarachnoid hemorrhage (OR 10.9, P < 0.01) were independent risk factors.

CONCLUSION

Location on the middle cerebral artery, multiplicity, aneurysm size of 5 mm or larger, and family history of subarachnoid hemorrhage are independent risk factors for aneurysm growth. These results may help to determine the treatment choice for unruptured aneurysms.