Abstract 301: Definitive Flow Diversion vs. Staged Flow Diversion After Temporizing Coil Embolization for Ruptured Intracranial Aneurysms: A Propensity Score‐Matched Analysis

Introduction Management of ruptured intracranial aneurysms has been largely shaped by the ISAT, BRAT and CARAT studies, which primarily compared microsurgical clipping with simple coil embolization (CE). These studies established coil embolization as the mainstay endovascular approach for ruptured aneurysms. Although a range of intraluminal and intrasaccular devices have since been developed, their use in the setting of rupture remains relatively underexplored; they are typically reserved for staged, definitive management following initial dome protection with conventional CE. We compared complication profiles and rates of complete aneurysm occlusion between upfront definitive flow diversion (UFD) and staged flow diversion (SFD) following initial temporizing CE in ruptured aneurysms. Methods We retrospectively reviewed an institutional flow diversion database. Following logistic regression, confounding variables were addressed through propensity score matching (PSM) without replacement, applying a match threshold of 0.1. Results Fifty‐three ruptured aneurysms underwent FD, 39 with UFD and 14 had SFD (Table‐1). SFD was performed in patients with larger subarachnoid bleeds (p<0.001) and symptomatic presentation (GCS, p=0.012; HH, p=0.007), mainly arising from large (dome height, p=0.002) saccular (morphology, p=0.001; higher DNR, p=0.004; fewer wide‐neck, p=0.019). After PSM, the UFD cohort housed a higher proportion of anterior (p=0.087) off‐label (p=0.087) aneurysm locations with comparable, complicated aneurysm morphologies as before PSM (fusiform and blister morphologies, p=0.003; low DNR, p=0.005). Before and after PSM, complication profiles or aneurysm occlusion rates were comparable, despite shorter DSA follow‐up in the UFD cohort. Post‐hoc comparison between just saccular variants showed that SFD had worser presentation and larger aneurysms (Table‐2). Conclusion UFD and SFD were utilized for divergent cohorts, with UFD rarely employed for clinically severe, large ruptured saccular aneurysms. However, the effectiveness and safety of UFD in managing more complex aneurysm morphologies suggest its potential applicability to large saccular variants, particularly in the absence of severe subarachnoid hemorrhage. image image