Atherosclerotic changes of the parent artery associated with ruptures in small (<7 mm) anterior communicating artery aneurysms.

Background: Small unruptured aneurysms are usually considered low-risk lesions and are typically managed conservatively. However, recent evidence indicates that small aneurysms account for a substantial proportion of ruptured intracranial aneurysms. Objective: To determine which morphology- and hemodynamics-related parameters are associated with the rupture status of small (<7 mm) anterior communicating artery (ACoA) aneurysms. Methods: We retrospectively reviewed 332 consecutive patients with ACoA aneurysms who were treated at our institute. Clinical data, imaging data, and intraoperative video recordings were reviewed and analyzed. Results: In total, 317 patients with small (<7 mm) ACoA aneurysms were included in the study, among whom 220 (69.4%) presented with ruptured aneurysms and 97 (30.6%) with unruptured aneurysms. The ruptured aneurysms showed a significantly higher height-to-width ratio, aspect ratio, and size ratio than the unruptured aneurysms ( Conclusion: Our study demonstrated that the rupture of small (<7 mm) ACoA aneurysms may be associated with the parent artery and aneurysmal neck atherosclerosis, the hemodynamic environment, and adverse morphological characteristics.