Endovascular treatment of unruptured aneurysm arising from duplicate origin of the middle cerebral artery – A case report and literature review

Duplicate origin of the middle cerebral artery (MCA) is a rare variation of MCA, often mislabeled as the fenestration of the M1 segment of MCA. The authors treated an unruptured aneurysm, 8 mm in diameter, associated with a duplicate origin of MCA in a 42-year-old woman who underwent magnetic resonance imaging for transient vertigo. Clipping surgery was inapplicable due to the lack of space to insert clip blades between the neck and two origins of MCA. Under stent-assisted maneuver, the aneurysm sac was successfully obliterated using three coils, resulting in Raymond-Roy class 1 occlusion status. Digital subtraction angiography performed 3 months after the embolization showed complete obliteration of the aneurysm. So far, only 11 patients with aneurysms associated with duplicate origin of MCA have been reported. We performed a literature review of this very rare combination. The size of aneurysms ranged from 2 to 8 mm, with a mean of 5.2 mm. The neck of the aneurysm is mainly located at the corner between the inferior limb and the internal carotid artery. Ours is the youngest and has the largest aneurysm. Aneurysm can arise from duplicate origin of MCA, for which stent-assisted coiling may be an appropriate treatment modality.