BACKGROUND AND PURPOSE:The endovascular treatment (EVT) of cerebral aneurysms has experienced a revolution since 1991 with the introduction of platinum coil technology. During the past 10 years, there has been significant study of the feasibility of this technique, and clinical results of EVT have been published. The long-term durability of Guglielmi detachable coil (GDC) embolization of cerebral aneurysms still remains unknown. The purpose of this study was to evaluate the stability of anatomic occlusion of aneurysms and to assess the rate of recanalization and retreatment of these aneurysms.