693 Treatment Differences of Ruptured Versus Unruptured Wide Neck Aneurysms: Insights From the EVERRUN Registry

INTRODUCTION: Wide neck aneurysms (WNAs) are more challenging to treat compared to narrow neck aneurysms, requiring more advanced techniques. The Wide Neck / EVERRUN Registry compared endovascular versus microsurgical techniques for unruptured and ruptured aneurysms. METHODS: Saccular and not previously treated WNA were examined. WNA definition was aneurysm neck=4mm or dome-to-neck-ratio (DTNR)<2. Differences in treatment strategy (EVT vs. MS) and angiographic results were the primary outcomes. Angiographic outcome was assessed immediately following treatment and at last follow-up using the Raymond-Roy scale (core lab review, adequate occlusion: RR 1-2). Statistical significance set at p<0.05. All analysis performed using R(v.4.2.1). RESULTS: 310 WNA were included (87 ruptured (R) aneurysms vs. 223 unruptured (U)). There were no significant differences in the rate of EVT vs. MS between ruptured (R) vs. unruptured (U) aneurysms (Clipping, R: 36.8%, U: 37.7%). Amongst EVT, ruptured WNA were treated more with stand-alone coiling (R: 27.6%, U: 5.8%) and balloon-assisted coiling (R: 32.2%, U: 10.8%). Unruptured aneurysms were more commonly treated with flow diversion (R: 1.1%, U: 22.9%) and stent-assisted coiling (R: 2.3%, U: 21.5%) (p < 0.05 for all). Ruptured aneurysms had higher rates of adequate angiographic occlusion after initial treatment (R: 88.5%, U: 74.3%) (p < 0.05). There was no difference in final adequate occlusion at follow-up (R: 90.1%, U: 90.7%). Ruptured WNA had higher retreatment rates (R: 14.3%, U: 3.1%) (p < 0.05). Ruptured WNA had more procedural complications (R: 28.7%, U: 17%) (p < 0.05). Rates of good mRS (0-2) at one year were higher in unruptured WNA patients (R: 72.8%, U: 90.3%) (p < 0.05). CONCLUSIONS: WNA rupture status significantly influences the EVT choice, likely based on the need for DAPT. The lower initial adequate occlusion in the unruptured cohort is likely due to more flow diverter use. Ruptured WNAs were more difficult to treat as evidenced by higher rates of retreatment and procedural complications, however this did not impact the final angiographic outcomes.