Multiple intracranial aneurysms: An international consensus statement

Introduction: Multiple intracranial aneurysms (MIAs) pose diagnostic and therapeutic challenges, and widely used rupture-risk scores have not been validated for this subgroup. Research question: To develop expert-based recommendations for the diagnosis, rupture-risk assessment, treatment selection, and follow-up of patients with MIAs. Material and methods: A modified Delphi process was conducted. After topic generation from the literature, iterative questionnaires were administered anonymously online to invited experts. Consensus was prespecified as ≥70% agreement. Twenty-six of 35 invitees (74.3%) completed the survey. Results: Consensus identified the ruptured lesion in aneurysmal subarachnoid hemorrhage (aSAH) using computed tomographic angiography (CTA) and 3D rotational digital subtraction angiography (3D-DSA). Increased rupture risk factors included aneurysm size, irregular morphology, posterior circulation location, prior hemorrhage, smoking, and family history. Individualized management was endorsed, with decision drivers such as aneurysm characteristics, patient factors, and institutional expertise. For microsurgery, a unilateral fronto-lateral approach was preferred; for endovascular therapy, coiling was favored for unruptured lesions. Annual imaging for untreated MIAs was recommended, but no consensus was reached on a rupture-risk scale or follow-up protocols. Discussion and conclusion: This consensus emphasizes the importance of accurately identifying aneurysm sources in cases of aSAH and advocates for personalized, multidisciplinary care. While single-stage treatment is recommended when safe, gaps remain, such as the lack of MIA-specific risk score validation and the best practices for post-treatment surveillance. Further multicenter research is needed to address these issues.