Anatomic Features of Paraclinoid Aneurysms: Computed Tomography Angiography Study of 144 Aneurysms in 136 Consecutive Patients

Abstract BACKGROUND Paraclinoid aneurysms are among the most challenging aneurysms to treat. Computed tomography (CT) angiography helps in evaluating the radiological characteristics of these aneurysms next to bony structures. OBJECTIVE To present the CT angiography characteristics of paraclinoid aneurysms in order to better understand such pathology. METHODS The study examined CT angiography-based anatomical characteristics obtained retrospectively from 136 patients with 144 paraclinoid aneurysms selected from single-defined catchment populations in Finland. We examined the diameters of the parent artery (internal carotid artery), the location of the aneurysm, its dimensions (width, height, neck), and aneurysm wall irregularity. RESULTS We analyzed 144 paraclinoid aneurysms in 136 patients admitted to the hospital during 2000-2014. Multivariable analysis reveals that rupture aneurysms have the following radiological features: aneurysm larger than 5 mm in diameter ( P = .006), irregular wall ( P = .046), superior location, larger aspect ratio ( P = .039), and neck wider than parent artery ( P < .001). CONCLUSION Smaller diameter of the internal carotid artery and superior location, as well as a large and irregular aneurysm wall, are radiological characteristics of ruptured paraclinoid aneurysms, which CT angiography can measure easily.