2085 Ruptured Versus Unruptured Aneurysm Treatment Varies Significantly by Location in a Multi-Center Aneurysm Registry

INTRODUCTION: Intracranial aneurysm location influences the risks of both rupture and treatment. Aneurysms at the anterior (ACOM) and posterior (PCOM) communicating arteries, as well as in the posterior circulation have been associated with a higher risk of rupture, while posterior circulation aneurysms have higher treatment risks. METHODS: Data from the NeuroVascular Quality Initiative-Quality Outcomes Database (NVQI-QOD) intracranial aneurysm registry were analyzed and compared for 4,056 consecutive ruptured and unruptured aneurysm treatments at 16 different centers, comparing aneurysm locations and sizes. RESULTS: Amongst 1,438 ruptured and 2,618 unruptured aneurysm treatments, the most common locations were the anterior communicating artery (ACOM, n=818), posterior communicating artery (PCOM, n=533), and internal carotid “other” (ICA “other”, n=510). The median (IQR) size of treated aneurysms was 6.0 mm (4.0-8.0) for ruptured aneurysms, and 6.0 mm (4.5-8.5) for unruptured aneurysms (p=0.046). For intradural aneurysms, the ratio of ruptured to unruptured treatments varied significantly by location (p<0.001), with the lowest ratios noted for aneurysms of the internal carotid artery including the carotid cave (0 ruptured/31 unruptured, ratio=0.0), superior hypophyseal (11 ruptured/96 unruptured, ratio = 0.11), ophthalmic artery (31 ruptured/225 unruptured, ratio = 0.13), and ICA “other” (76 ruptured/434 unruptured, ratio = 0.18). The highest ratios of ruptured to unruptured treatments were noted at the posterior inferior cerebellar artery (PICA, 85 ruptured/64 unruptured, ratio = 1.3), PCOM (289 ruptured/284 unruptured, ratio = 1.0), and ACOM (418 ruptured/400 unruptured, ratio = 1.0). CONCLUSIONS: Significant variation by location was noted in aneurysm treatment, with a greater than ten-fold difference in ruptured to unruptured treatment ratios at different locations. Targeting treatment of unruptured aneurysms to high-risk locations may prevent rupture while reducing unnecessary treatments.