Natural history and treatment of asymptomatic unruptured carotid cavernous aneurysms: a systematic review and meta-analysis

Background: The management of asymptomatic carotid cavernous aneurysms (CCAs) is debated. While their rupture risk is low, the potential for growth and symptom development creates a clinical dilemma, particularly with the evolution of advanced endovascular treatments. This study aims to synthesize the evidence on the natural history of asymptomatic CCAs and the outcomes of intervention. Methods: A systematic review of PubMed and Scopus was conducted per PRISMA guidelines. We included retrospective studies reporting on the management of asymptomatic CCAs with five or more patients. A proportional meta-analysis was performed to calculate pooled outcomes for conservative and active management cohorts separately, as the observational nature of the included studies precluded direct comparative analysis. Results: Eleven studies met the inclusion criteria, encompassing 557 patients. Conservative management was the initial strategy in 75.0% of cases (n=418), while 25.0% (n=139) underwent active treatment. In the conservatively managed cohort, 8.1% of patients developed new neuro-ophthalmic symptoms. Radiologically, 91.5% of followed aneurysms remained stable. Aneurysm size was the strongest predictor of progression, with large aneurysms (≥12 mm) showing a 19.2% annual growth risk. Active treatment achieved a pooled aneurysm occlusion rate of 85.7% but was associated with complications, including a 2.9% rate of ischemic events. Conclusion: The natural history of asymptomatic CCAs is largely benign, but progression is strongly linked to aneurysm size. Our findings support a risk-stratified approach: conservative management with serial imaging for small (<12 mm) aneurysms and consideration of intervention for larger or growing lesions.