Abstract Body: Introduction and Hypothesis: Unruptured intracranial aneurysms (UIAs) are prevalent and increasingly discovered through non-invasive imaging. Our understanding of the risks of treatment is guided predominantly by single-center retrospective series and administrative claims-based studies. The goal of this study was to identify factors associated with poor short-term functional outcomes in a multi-center registry of electively treated UIAs.

Methods: The NeuroVascular Quality Initiative-Quality Outcomes Database (NVQI-QOD) database was queried for all electively treated UIAs. Patient, aneurysm, and treatment characteristics were recorded and used to identify univariate predictors of poor short-term functional outcome (discharge mRS > 2). Factors significant on univariate analysis were used to construct a multivariate binary logistical regression model to identify independent predictors of short-term poor clinical outcomes.

Results: Among 1,929 aneurysm treatments for UIA, the median (Q1-Q3) patient age was 61 (51-69), 1,456 (75.5%) were women, and 1,283 (66.8%) were non-Hispanic whites. Treated aneurysm sizes included 258 (14.7%) < 4 mm, 744 (42.4%) 4-7 mm, 548 (31.2%) 7-12 mm, 176 (10.0%) 12-25 mm, and 28 (1.6%) > 25 mm. Anterior circulation aneurysms comprised 1,610 (83.5%) of treatments, and the median (Q1-Q3) aneurysm dome/neck ratio was 1.6 (1.3-2.2). Endovascular treatment was performed in 1,714 (88.8%) of patients. Microsurgery was used most commonly at the middle cerebral artery (36.2%) and anterior communicating artery (10.1%) locations. At discharge, poor functional status of mRS > 2 was noted in 95 (4.9%) of patients, with death in 13 (0.7%). Independent predictors of poor functional status included non-white race (OR 2.02, 1.14-3.52), aneurysm size < 4 mm (OR 2.3, 1.07-4.84, compared to 4-7 mm), aneurysm size 12-25 mm (OR 2.62, 1.1-5.94, compared to 4-7 mm), aneurysm size > 25 mm (OR 12.97, 4.03-38.9, compared to 4-7 mm), and microsurgical treatment (OR 4.29, 2.24-8.03).

Conclusions: In a large multi-center registry, mRS > 2 at discharge was noted in 4.9% of electively-treated UIA, with mortality in 0.7%. Independent predictors of poor short-term outcome included non-white race, small (< 4 mm), large (12-25 mm), and giant (> 25 mm) aneurysm size, and microsurgical treatment.