The rupture risk factors of mirror intracranial aneurysms: A systematic review and meta-analysis based on morphological and hemodynamic parameters

OBJECTIVE: Intracranial aneurysms (IAs) are a prevalent form of vascular disease that can lead to fatal outcomes upon rupture. Mirror intracranial aneurysms (MIAs) are a specific type of multiple aneurysms situated symmetrically on both sides of the parent arteries. The factors contributing to the risk of MIA rupture, based on morphological and hemodynamic parameters, are currently controversial. Thus, we conducted a systematic review and meta-analysis to investigate the risk factors for MIA rupture. METHODS: The study performed an electronic search of Chinese and English databases, including China national Knowledge Infrastructure (CNKI), WanFang, VIP, PubMed, Embase, Web of Science, Scopus, and the Cochrane Library databases, and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The morphological parameters (IA size, aspect ratio [AR], size ratio [SR], bottleneck factor [BNF], height-width ratio [HWR], irregular shape) and hemodynamic parameters (wall shear stress [WSS], low WSS area [LSA], oscillatory shear index [OSI]) were analyzed for their significance in determining the risk of MIA rupture. RESULTS: The analysis comprised 18 retrospective studies involving 647 patients, with a total of 1294 IAs detected, including 605 ruptured and 689 unruptured. The meta-analysis revealed that IA size, AR, SR, and irregular shape exhibited significant differences between the ruptured and unruptured groups, but HWR did not. In terms of hemodynamic parameters, WSS, OSI, and LSA were found to have significant differences between the two groups. CONCLUSIONS: Our results demonstrate that larger IAs, higher AR, SR, and BNF are associated with a higher risk of rupture in patients with MIAs, regardless of their location. there is no significant difference in HWR between the ruptured and unruptured groups. These preliminary findings offer valuable insights for clinical decision-making and a more comprehensive comprehension of the current MIA status. Nevertheless, larger and multi-center studies are indispensable for corroborating these findings. Systematic review registration: https://www.crd.york.ac.uk/prospero/ identifier: CRD42022345587.