Internal carotid bifurcation aneurysms: anatomical features and outcome of endovascular treatment.

This study reports the anatomical presentation of internal carotid bifurcation aneurysms and the angiographic results of their endovascular treatment. We treated 17 patients with internal carotid bifurcation aneurysms by endovascular treatment using detachable coils. Follow-ups were conducted for three to 30 months. The pre- and postprocedural anatomical features of the aneurysms, procedural complications, and postprocedural angiographic outcomes were evaluated. The aneurysmal necks were located just above the internal carotid artery bifurcation or at the origins of anterior cerebral artery or the middle cerebral artery. Immediate angiography demonstrated complete occlusion, neck remnant, or residual aneurysms. Post-treatment, two aneurysms that were initially residual spontaneously progressed to complete occlusion, and two large aneurysms that initially demonstrated complete occlusion or neck remnants showed coil compaction and recanalization. Procedural complications occurred in two cases. Endovascular treatment is effective for ruptured and unruptured carotid terminal aneurysms with various anatomical features.