True posterior communicating artery aneurysm associated with arteriovenous malformation: first report and literature review with special focus on flow alterations.

Introduction & True posterior communicating artery (PCoA) aneurysms represent extremely rare lesions, the precise frequency of which remains unknown. These aneurysms are located on the trunk of the PCoA and should be diff erentiated from common aneurysms, which involve the origin of the PCoA from the internal carotid artery (ICA). However, diagnosis of these aneurysms is diffi cult when they are located close to the ICA. In some of the previously reported cases, the correct diagnosis was only achieved during surgery [15, 17, 19, 38, 40] . Three dimensional (3D) reconstructions of digital substraction angiography (DSA) and / or computed tomography angiography (CTA) are needed for optimal preoperative evaluation and surgical treatment of these lesions.