Two surgical cases of internal carotid-ophthalmic artery aneurysms: special reference to the usefulness of three-dimensional CT angiography.

Three-dimensional computerized tomography angiography (3D-CTA) is a noninvasive tool for the diagnosis of cerebral aneurysms. 3D-CTA is helpful in the evaluation of the configuration of aneurysms and their surrounding vessels and anatomical structures. The aim of this study is to assess the usefulness of 3D-CTA for patients with unruptured internal carotid-ophthalmic artery aneurysms. We pre-operatively obtained surgical simulation images using 3D-CTA and 3D reconstruction and then compared them with magnetic resonance angiography (MRA), conventional cerebral angiography and operative findings in the patients. Two patients with unruptured internal carotid-ophthalmic artery aneurysm were selected. These patients underwent direct neck clipping after the optic canal was unroofed through a combined epidural-subdural approach. The cerebral aneurysm was detected by 3D-CTA, MRA and conventional cerebral angiography in each case. Only by 3D-CTA, however, could we easily detect the relationships among the aneurysm neck, ophthalmic artery and optic canal. Based on this information, direct clipping operations were performed safely without any complications. 3D-CTA is an excellent noninvasive diagnostic method not only for detecting cerebral aneurysms, but also for evaluating the relationships between the aneurysms and surrounding structures.