A De Novo Aneurysm of the Anterior Cerebral Azygos Artery Following a Middle Cerebral Arterial Aneurysm with Subarachnoid Hemorrhage

• Published in: NMC Case Report Journal Vol. 8; no. 1; pp. 309 - 314
• Main Authors: HONDA, Eiichiro, OHISHI, Tsuyoshi, MARUIWA, Hikaru, TANAKA, Tatsuya
• Format: Journal Article
• Language: English
• Published: Japan The Japan Neurosurgical Society 2021
• Subjects: arachnoid hemorrhage; arterial stress; azygos artery; Case Report; de novo intracerebral aneurysm; middle cerebral arterial aneurysm; middle cerebral arterial aneurysm; arachnoid hemorrhage; de novo intracerebral aneurysm; arterial stress; azygos artery
• ISSN: 2188-4226; 2188-4226
• DOI: 10.2176/nmccrj.cr.2020-0120

A de novo aneurysm of a cerebral artery, defined as a newly growing aneurysm after aneurysmal clipping, but not close to a previously clipped one, is relatively rare. Five studies have reported that the annual incidence of de novo aneurysm formation ranged from 0.3% to 1.8%. A 56-year-old man presented with headache. Magnetic resonance angiography (MRA) and computed tomography (CT) showed an aneurysm with arachnoid hemorrhage located at the left middle cerebral artery (MCA) associated with an azygos anterior cerebral artery (ACA). Eight years later, the patient complained of dizziness, and MRA demonstrated no visualization of the MCA on the left due to metal artifact, but a new lesion, an azygos ACA aneurysm, 9 mm in diameter, was seen. Clipping was performed using multiple clips through the interhemispheric space. Late follow-up examination with MRA or three-dimensional CT to detect de novo aneurysms should be considered in a patient with this vascular anomaly after subarachnoid hemorrhage.