Comparative Effectiveness of Surgical, Endovascular, and Conservative Strategies for Unruptured Intracranial...

This study compares microsurgical clipping, endovascular coiling, and conservative management strategies for unruptured intracranial aneurysms using network meta-analysis to generate a treatment hierarchy that supports evidence-based decision-making.

The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Network Meta-Analyses guidelines. Eligible studies included randomized controlled trials and comparative observational cohorts of adults with unruptured intracranial aneurysms treated by clipping, coiling, or conservative observation. Primary outcomes were all-cause mortality and poor functional outcome (modified Rankin Scale score >2). Secondary outcomes included morbidity, complete aneurysm occlusion, and retreatment. A comprehensive search of PubMed, Embase, and the Cochrane Library through May 2025 identified 7 eligible studies, of which 4 provided sufficient data for network analysis.

The 4 included studies, 1 randomized trial and 3 observational cohorts, encompassed >500 patients. All compared clipping and coiling, and 2 also evaluated conservative management. Endovascular coiling ranked most favorable for reducing mortality and poor functional outcomes, though estimates were imprecise. Clipping was associated with higher morbidity than coiling but demonstrated trends toward superior anatomic durability, including higher occlusion rates and fewer retreatments. Conservative management was linked to worse survival and functional outcomes, with limited data on anatomic end points. Subgroup analyses of anterior and posterior circulation aneurysms yielded similar patterns.

Endovascular coiling appears to offer the best short- to intermediate-term outcomes, whereas microsurgical clipping provides more durable long-term protection despite greater procedural risks. Conservative observation remains the least favorable strategy and may be reserved for highly selected low-risk patients. Further large-scale trials are needed, particularly in posterior circulation aneurysms and for patient-centered outcomes such as quality of life and cognition.