The prevalence of intracranial aneurysms (IAs) is higher in patients with aortic aneurysms. However, there are lack of studies investigating prevalence of thoracic aortic aneurysms (TAAs) in patients with IAs. The objective of this study was to evaluate the prevalence and risk factors for thoracic aortic dilatations (TADs) and TAAs in patients with IAs.

We retrospectively reviewed data from 1777 patients with diagnosed IAs at our institution between 2006 and 2016. We included 411 patients with saccular IAs and available imaging studies (computed tomography or magnetic resonance imaging) of all thoracic aortic segments. TAD was defined according to age- and sex-matched normograms, and TAA as a diameter of greater than 4.0 cm.

A total of 83 patients (20%) had TAD or TAA. The prevalence of TADs and TAAs were 18% (n = 74) and 8% (n = 31) without significant difference between unruptured and ruptured IAs (P = .7). Of the 74 patients with TAD, 22 (30%) had multiple TADs and 66% of the TADs located in the aortic arch. Older age (odds ratio [OR], 1.04; P = .006), rheumatic disease (OR, 4.73; P = .009) and alcohol abuse (OR, 4.77; P = .01) were significant risk factors for TAD/TAA.

The prevalence of TADs and TAAs is considerably greater in patients with IAs compared with reports from the general population, suggesting that IAs might be associated with aortopathy and might share a similar pathogenetic background with TADs/TAAs. Especially patients with IAs and a history of rheumatic disease and/or alcohol abuse are at high risk for TADs/TAAs.