Periprocedural (≤72 hours) safety of flow diverters versus alternative endovascular techniques for unruptured intracranial aneurysms

Background Flow diverters have expanded endovascular treatment options, yet large real-world data about their comparative periprocedural safety in the treatment of unruptured intracranial aneurysms are limited. This study aimed to compare the short-term safety of flow diverters with alternative endovascular techniques. Methods We analyzed 24 458 procedures for unruptured intracranial aneurysms recorded in the DEGIR (Deutsche Gesellschaft für Interventionelle Radiologie und minimal-invasive Therapie) endovascular registry between January 2018 and December 2025, across 154 German centers. A 1:1 propensity score-matched cohort was derived. The primary outcome was any periprocedural complication within 72 hours. Secondary outcomes were severe complications (permanent neurological deficit or death), hemorrhagic complications, and thromboembolic complications. Temporal trends were assessed using the interaction between flow diverter treatment and treatment year. ORs and 95% CIs are reported. Results We included 13 576 (6788 flow diverter, 6788 non-flow diverter) 1:1 propensity score-matched procedures in our analysis. Flow diverter treatment was not associated with a significant difference in overall (OR 1.09, 95% CI 0.94 to 1.26), thromboembolic (0.99, 0.81 to 1.21), hemorrhagic (1.30, 0.99 to 1.70), or severe complications (1.38, 0.94 to 2.02). No significant temporal trend was observed for any of the outcomes. Results were robust in sensitivity analyses comparing flow diverters with stent-assisted coiling and restricting the cohort to saccular aneurysms. Conclusions In a large national quality assurance registry, flow diverter treatment for unruptured intracranial aneurysms was not associated with a significant increase in periprocedural (≤72 hour) complication risk.