Abstract 365: Peri‐Procedural Complications, Clinical Outcomes and Recurrence/Retreatment Rates After Endovascular versus Microsurgical Treatment of Intracranial Aneurysms: A Real‐World Assessment from the NQVI‐QOD Cerebral Aneurysm Registry

Introduction Improved outcomes after endovascular treatment of ruptured aneurysms were shown in ISAT (N=2143), with improved functional independence over surgical clipping. Many acknowledge these data have been extrapolated to non‐ISAT and unruptured aneurysm populations in clinical practice, though some trials (e.g., BRAT) suggested that this may not be appropriate. Some studies do suggest fewer peri‐procedural complications with endovascular versus microsurgical treatment, although discrepancies exist in this literature. On the other hand, despite increasing adoption of endovascular treatments, there appear to be higher recurrence/retreatment rates compared to microsurgery. We report peri‐procedural complications, clinical outcomes, and retreatment rates from the NQVI‐QOD Cerebral Aneurysm Registry (N=6149) to demonstrate the real‐world practice of intracranial aneurysm treatment, providing important quality and performance benchmarks. Methods We analyzed 6149 aneurysm cases from the 2015‐2022 NQVI‐QOD database for demographic/risk factors, presentations, aneurysm characteristics, treatment types, peri‐procedural complications, angiographic and clinical outcomes at discharge and follow‐up, and recurrence/retreatment rates across 4 subsets: Ruptured‐Endovascular (N= 2087), Ruptured‐Surgical (N=348), Unruptured‐Endovascular (N=3220), and Unruptured‐Surgical (N=494). We performed descriptive analyses and inferential test of ordinal and categorical variables comparing endovascular and surgical treatment for unruptured and ruptured aneurysms. Results Intra‐operative complications occurred in 5.9% endovascular vs 4.5% surgical patients (p&lt0.05), with thrombus formation and aneurysm rupture the most common endovascular and surgical complications, respectively. Post‐operative complications occurred in 21.4% endovascular vs 27.3% surgical patients (p&lt0.01), with infection and ischemic stroke the most common among ruptured and unruptured aneurysms respectively, stroke being lower in endovascular patients compared to surgical (p&lt0.01). Although there was no difference for in‐hospital mortality, for ruptured aneurysms, 64% endovascular vs 49% surgical patients (p&lt0.01) were functionally independent at discharge, with 78% endovascular vs 76% surgical patients (p=0.4) discharged to home/rehab. For unruptured aneurysms, 94% endovascular vs 81% surgical patients (p&lt0.01) were functionally independent at discharge, with 97% endovascular vs 95% surgical patients (p=0.4) discharged to home/rehab. At follow‐up of patients with ruptured aneurysms, 87% endovascular vs 81% surgical patients (p=0.02) were functionally independent, with 94% endovascular vs 86% surgical (p=0.01) living at home. For unruptured aneurysms, 95% of endovascular vs 91% surgical patients (p=0.047) were functionally independent with 97% endovascular vs 97% surgical living at home. Post‐procedure angiographic outcomes were similar for ruptured and unruptured aneurysms. However, recurrence/retreatment occurred in 15% endovascular (21% ruptured, 11% unruptured) vs 7% surgical patients (p&lt0.01). Conclusion In our study, endovascular treatment of intracranial aneurysms was associated with better short term clinical outcomes than microsurgical clipping across both ruptured and unruptured aneurysms. Intraoperative complications were similar across techniques. Post‐operative complications were lower for the endovascular cohort regardless of presentation. Long term outcomes were similar, but there was higher recurrence/retreatment in the endovascular group. Overall, these data suggest pros and cons of various treatments of both ruptured and unruptured aneurysms, with likely more challenging recoveries but perhaps more durable results from microsurgery.