Comparison of flow diverter alone versus flow diverter with coiling for large and giant intracranial aneurysms: systematic review and meta-analysis of observational studies

BACKGROUND: Large and giant intracranial aneurysms pose treatment challenges. The benefit-risk balance of flow diverters (FDs) alone versus FDs with coiling remains unclear. This study aimed to compare these two strategies. METHODS: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search of PubMed, Embase, Scopus, Cochrane, and Web of Science was performed up to October 2024. Studies comparing FDs with or without adjunctive coiling in large/giant intracranial aneurysms were included. The primary outcome was complete aneurysm occlusion, defined by the Raymond-Roy Occlusion Classification. Additional outcomes included procedural and postprocedural complications. Data were analyzed using a random effects model. RESULTS: 15 studies with 1130 patients were analyzed, with 557 in the FD alone group and 573 in the FD+coiling group. The meta-analysis revealed that FD+coiling significantly improved complete aneurysm occlusion rates (OR 1.59, 95% CI 1.06 to 2.40, P=0.03). While overall ischemic complications were significantly lower in the FD alone group, a sensitivity analysis showed no significant difference (OR 0.49, 95% CI 0.20 to 1.23, P=0.13). Subgroup analysis of fusiform aneurysms showed no significant difference in complete aneurysm occlusion rates (OR 1.10, 95% CI 0.50 to 2.40, P=0.82). Procedural and hemorrhagic complications did not differ significantly, and no publication bias was detected in the results. CONCLUSIONS: Combining FDs with coiling improved complete aneurysm occlusion rates in large and giant saccular intracranial aneurysms, although the impact on complications remains controversial. Further investigation into the benefit-risk ratio of this combined approach is warranted.