Morphological irregularity of unruptured intracranial aneurysms is more related with aneurysm size rather than cerebrovascular atherosclerosis: A case-control study

Abstract

Objective: It remains unclear whether irregular morphological features of intracranial aneurysms (IAs) are associated with atherosclerosis. We investigated the effect of cerebro-vascular atherosclerosis stenosis (CAS) on irregular morphology of IAs. Patients and Methods: This single-center case-control study included consecutive patients with IAs at our institution from September 2011 to September 2018. Cases were patients with irregular IAs, and age-and location-matched controls were patients with regular IAs. Conditional logistic regression models were used to assess the relationship between angio-graphic variables of CAS and aneurysmal irregularity. Results: A total of 140 cases of irregular IAs and 140 controls were included in the analysis. Sixteen patients with irregular IAs (11.4%) and eleven patients with regular IAs (7.9%) had >50% parent artery stenosis; however, the differences were not statistically significant between these two groups. In addition, no significant between-group differences were observed in distributions of the cerebrovascular stenosis, number of arterial stenoses, and location of the stenosis. In the final adjusted conditional logistic regression model, only aneurysm size (≥7 mm) was significantly associated with irregular IA morphology (P = 0.022). Moreover, 89 cases of irregular IAs and 89 controls were included in the analysis of unruptured IAs (UIAs). In the final adjusted conditional logistic regression model, only aneurysm size (≥7 mm) was significantly associated with irregular UIA morphology (P = 0.020). Conclusion: Our findings indicate that the morphological irregularity of unruptured intracranial aneurysms is more related with aneurysm size rather than cerebrovascular athero-sclerosis. Further studies are needed to use prospective data to identify causative factors responsible for aneurysmal irregularity.