Posterior communicating artery aneurysms demonstrate faster interval growth than other growing aneurysms.

Background Posterior communicating artery aneurysms are often associated with a high rupture risk. This study compares the differences in the rate of growth and morphological characteristics between growing posterior communicating artery aneurysms and other types of growing aneurysms. Materials and methods Thirteen patients with growing internal carotid artery aneurysms were scanned using Siemens 64 slice computed tomography scanners. Three patients had ophthalmic aneurysms, three had superior hypophyseal aneurysms and seven had posterior communicating artery aneurysms. Each aneurysm case had three distinct time points, with an average separation time of 1.3 ± 0.6 years. Annual aneurysm dimensional growth, annual volume growth, annual increase in surface area, size ratio, aspect ratio, and non-sphericity index were analysed. Results Posterior communicating artery aneurysms demonstrated significantly higher annual increases in dimensional growth, volume and surface area when compared to other internal carotid artery aneurysms. Posterior communicating artery aneurysms also demonstrated a significantly higher increase in aspect ratio, size ratio and lower non-sphericity index. Discussion Posterior communicating artery aneurysms had significantly greater growth per year when compared to other types of internal carotid artery aneurysms, and had different morphological characteristics.