Relationship Between Intracranial Aneurysms And Internal Carotid Artery Stenosis

Background: Intracranial aneurysm in general population is pretty common. But the aneurysm rupture and subsequent subarachnoid hemorrhage is associated with a mortality rate of 40-55%. The risk factor of Intracranial aneurysm include: female gender, increasing age, smoking, hypertension, alcohol use etc. While the carotid artery stenosis is associated with male gender, dyslipidemia, smoking, hypertension, diabetes mellitus. The treatment strategies must balance the risk of ischemic stroke with the risk of aneurysmal rupture, which will lead to higher mortality. According to this, it’s very important to investigate the pathogenesis of this tandem lesion. This research focused to explore whether the atherosclerotic disease and hemodynamic change play an important role in the patient concomitant with intracranial aneurysms and internal carotid artery stenosis.Methods: We performed a retrospective review of all patients with intracranial aneurysms and internal carotid artery stenosis who underwent CTA scan at our hospital between January 2011 and August 2015, for all patients, we determined the proportion of the aneurysms in all patient and stenosis patient. Medical records were reviewed for hospitalization patients’ demographic and clinical data. Patients were stratified into 2 groups: unilateral stenosis and bilateral stenosis, and then unilateral stenosis was divide into another two groups: aneurysms located at ipsilateral side and contralateral side.Results: we received 311 patients with intracranial aneurysms and internal carotid artery stenosis in all 13666 scanned patients. The prevalence of aneurysms was 11.9% in all patients and 12.3% in patients with stenosis, respectively. In 125 hospitalization patients, 154 aneurysms were detected. The average aneurysm size was 4.7±2.4mm, and the patients were mostly older than 60(68±10). Patients with bilateral stenosis were more likely associated with multiple intracranial aneurysms(P=0.047) and hyperlipemia(P=0.042). The laterality of aneurysms was evenly distributed between the ipsilateral and contralateral side of the carotid stenosis(P>0.05), but aneurysms were more prevalent in the contralateral side of the severe stenosis(P=0.041), and ipsilateral side of mild stenosis(P=0.034).Conclusion: Internal carotid artery stenosis seems to be a important factor in the formation and growth of aneurysms, it might explained by the atherosclerosis and hemodynamic change. In this research, we found that stenosis would influence the number and position of intracranial aneurysms.