Multiple and mirror intracranial aneurysms: study of prevalence and associated risk factors

Abstract

Objective

Multiple intracranial aneurysms (MIA) account for 30% of all intracranial aneurysms, while mirror aneurysms, a subgroup of MIA, are present in 5% of all patients with cerebral aneurysms. We investigated the risk factors associated with the presence of multiple and mirror intracranial aneurysms.

Methods

1404 patients, 314 males (22.4%) and 1090 female (77.6%) were enrolled for this study. Diagnosis was performed with a digital subtraction angiography (DSA). Multiplicity was defined as the presence of two or more aneurysms and mirror aneurysms as one pair of aneurysms involving bilateral corresponding arteries. Patients were followed-up from September 2009 till August 2018. Individuals’ characteristics such as sex, age, smoking, hypertension and use of contraceptives were evaluated.

Results

Five hundred and twelve patients (36.4%) were diagnosed with MIA, approximately 4%/year. We observed 203 pairs of mirror aneurysms, accounting for 406 aneurysms (13% of the population). There was an increased frequency of females with multiple (p < 0.001, OR = 1.883, 95% CI = 1.386–2.560) and mirror aneurysms (p < 0.001, OR = 2.828, 95% CI = 1.725–4.636). Smoking was associated with multiplicity (p< 0.001, OR = 1.458, 95% CI = 1.160–1.833), as well as advanced age (p < 0.001, OR = 1.938, 95% CI = 1.438–2.611), but there was no significant relation with presence of mirror aneurysms. We observed higher frequency of baby aneurysms (<3mm) in the group of patients with MIA, while giant aneurysms (>25 mm) were most found in patients with only one aneurysm (p < 0.001). No differences between patients who used contraceptives against patients who did not use were found (p = 0.600).

Conclusions

Gender and smoking, known risk factors to the development of a single intracranial aneurysm, are proportionally increased in patients with MIA. Hypertension and oral contraceptives were not associated with multiplicity.

Keywords:

• Multiple
• mirror
• intracranial
• aneurysms

Disclosure statement

The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article. All authors certify that they have no affiliations. The authors declare have no conflicts of interest.

This work has been accepted as an oral presentation abstract at the AANS Annual Meeting, April 2019, San Diego, CA, USA, entitled Multiple Intracranial Aneurysms: Incidence and Risk Factors.