A case of a patient with a true large unruptured posterior communicating artery (PCoA) aneurysm in a distal segment of PCoA, who was treated by interventional therapy via an ipsilateral occlusion of the internal carotid artery (ICA), is reported. Although the treatment went very well and the patient recovered very well, angiography 6 months after the operation showed that left PCoA had occluded and the aneurysm disappeared. The temporary recanalization of occluded ophthalmic segment of ICA can be a pathway for interventional therapy. Mechanism and preventive measures for spontaneous occlusion of the PCoA harboring an aneurysm still needs further study.
Keywords: Endovascular treatment; internal carotid artery occlusion; parent artery occlusion; posterior communicating artery aneurysm.