Intracranial Arterial Tortuosity According to the Characteristics of Intracranial Aneurysms

Objective Intracranial aneurysm (IA) is the leading cause of subarachnoid hemorrhage. The pathomechanisms of IA are poorly understood but can be related to arterial tortuosity resulting from underlying systemic factors leading to arterial wall weakening. We aimed to analyze the tortuosity of the intracranial artery in a cohort with IA, hypothesizing that the tortuosity of intracranial arteries differs depending on the characteristics of the IA. Methods Patients with saccular IA were consecutively enrolled. Clinical factors and vascular tortuosity of the right and left middle cerebral arteries and basilar artery (BA) of all patients with IA were compared according to the characteristics of the IA: 1) ruptured versus unruptured, 2) multiple versus single, and 3) large (>5 cm) versus small (≤5 cm). Unruptured IAs were comparatively analyzed according to aneurysm size and aspect ratio, whereas ruptured IAs were analyzed according to aneurysm size. Results Two hundred eighty-five patients were enrolled (mean age, 59 years; 71.2% women). The tortuosity of the BA was higher in the large IA group (5.63 ± 6.26; n  = 133; P  = 0.009), large unruptured IA group (6.64 ± 6.32; n  = 53; P  = 0.039), and large ruptured IA group (5.50 ± 6.52; n  = 80; P  = 0.033) compared with the small IA, small unruptured IA, and small ruptured IA group. In multivariate analysis, increased BA tortuosity was significantly associated with large IAs (β = 1.066; P  = 0.008), unruptured large IAs (β = 1.077; P  = 0.033), and ruptured large IAs (β = 1.086; P  = 0.025). Conclusions The BA tortuosity was higher in patients with large IAs, which may represent an imaging biomarker of aneurysm growth.