Reliability of Bony Landmarks to Predict Intradural Location of Paraclinoid Aneurysms.

Abstract

When dealing with paraclinoid carotid aneurysms, the distinction between intradural and extradural location is amajor component for decision-making as only intradural aneurysms carry arisk of subarachnoid hemorrhage (SAH). The aim of this study was to test the accuracy and reliability of computed tomography (CT) bony landmarks for the distinction between intradural and extradural paraclinoid aneurysms. All patients referred to this institution for asingle paraclinoid aneurysm were retrospectively identified. The study included only the patients who presented with diffuse SAH, thus proving the intradural location of the aneurysm. The preoperative images were assessed by two physicians in order to locate the aneurysms using the tuberculum sellae (TS) and the optic strut (OS) landmarks. A total of 15 patients were included in the study. There were 4cases (27%) of disagreement with the OS bony landmark and no cases of disagreement with the TS landmark. No aneurysm was consensually considered as extradural by both readers with both bony landmarks; however, five aneurysms (33%) were considered to be extradural by at least one of the physicians with at least one of the two bony landmarks. The results of the study showed several disagreements when using the OS landmark. More importantly, several aneurysms were considered as extradural with at least one of these two CT bony landmarks, even though they were all associated with an SAH. More reliable and accurate landmarks are warranted.