Abstract 354: Outcomes in Severity‐Stratified Subarachnoid Hemorrhages using Endovascular Coiling and Microsurgical Clipping

Introduction/Purpose Non‐traumatic subarachnoid hemorrhage (SAH) is an emergent medical condition characterized by acute onset bleeding into the subarachnoid space. Rupture of a saccular or berry aneurysm is the primary cause (85%), but other etiologies include other cerebral aneurysms, arteriovenous malformation, aortic dissection, and other vascular abnormalities. Historically, aneurysm clipping was the primary modality of treatment. The standard of care changed when the ISAT study established endovascular coiling as a better, less invasive alternative. The objective of this study was to describe mortality following intervention for aneurysm rupture using real‐world data with extensive control for severity of the resulting hemorrhage. Materials/Methods This retrospective cohort study analyzed survival data from a cohort of patients with ruptured intracranial aneurysms and recorded GCS who underwent endovascular coiling (n=634) and microsurgical clipping (n=223). Data were pulled from the TriNetX Research Network. One‐year mortality was assessed and compared using Cox proportional hazard models. Propensity score matching was used to control for demographics, comorbidities, the National Inpatient Sample‐SAH Severity Scale (NIS‐SSS) criteria, and GCS. Results When not controlled for severity, an analysis of 3,647 patients matched on all criteria except for GCS, the hazard of mortality was significantly elevated for coiling (HR=1.16; 1.02, 1.33). The cumulative one‐year survival was 86.6% in coiling and 88.3% in clipping. However, when the severity was controlled for using GCS (n=106 of each), patients with mild‐moderate hemorrhages (GCS 9‐15) had one‐year cumulative survival rates of 87.8% for coiling and 93.4% for clipping. Survival analysis showed that coiling was not associated with increased hazard of one‐year mortality (HR=1.74; 95% CI: 0.68, 4.41). Among patients with severe hemorrhages (GCS 3‐8), the cumulative survival rates were 41.3% for coiling and 51.8% for clipping, after matching (n=56 of each). The one‐year mortality hazard associated with coiling was also not significant in this population (HR=1.40; 0.83, 2.37). Conclusions: There were no significant differences in one‐year mortality between clipping and coiling in both mild‐moderate and severe SAH after ruptured intracranial aneurysms. Further research is needed to establish the differences in severity between the two groups and understanding the true hazards with larger cohorts.