[Endovascular treatment of basilar artery aneurysms associated with proximal fenestration--report of two cases].

Fenestration refers to the localized duplication of a vessel. This developmental anomaly has tendency to form aneurysms caused by the defect in the media of the arterial wall. We present two cases of successful endovascular treatment of a saccular aneurysm associated with fenestrated basilar artery at its proximal end. One of these aneurysms was firstly partially embolized with mechanically detachable coils and then, after one year follow-up, a stent implantation was performed. The second patient underwent a complete, one step embolization with mechanically detachable coils.