Site-Specific Relationship Between Intracranial Aneurysm and Aortic Aneurysm.

BACKGROUND AND PURPOSE The high prevalence of intracranial aneurysms (IAs) in patients with a bicuspid aortic valve or coarctation of the aorta suggests a link between IA and aortic pathology. However, studies reporting this link do not sufficiently address the heterogeneity of IAs arising from different anatomic locations. This study aimed to explore whether a location-specific relationship exists between the 2 kinds of aneurysms. METHODS Retrospective institutional analysis of patients aged ≥18 years with both IA and an aortic aneurysm (AA) was performed from 2005 to 2014. IAs were categorized based on their locations: internal carotid artery, other anterior circulation, and posterior arteries. AAs were classified as ascending, descending, infrarenal, or multiple. We analyzed the clinical characteristics and the distribution of IA in each AA group. RESULTS Of 2375 patients, 660 with available intracranial angiography were screened for IA. We identified 71 patients with 97 IAs. The frequency of both anterior circulation-IAs and internal carotid artery-IAs differed significantly among the AA groups (P=0.001 and P=0.01, respectively). Anterior circulation-IAs were most frequently observed in ascending AA group and least frequently in infrarenal AA group. In contrast, internal carotid artery-IAs were found mostly in infrarenal AA group, least in ascending AA group. Proportions of patients having anterior circulation-IA and internal carotid artery-IA were also highest in ascending AA group and infrarenal AA group, respectively. The number of posterior arteries-IAs was too small to characterize. CONCLUSIONS The differing distribution patterns of IA among AA groups suggest a site-specific sharing of pathomechanism between the 2 types of aneurysms.