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.