High resolution MRI in treatment decision of anterior communicating artery aneurysm accompanied by visual symptoms: Endovascular treatment or surgical clipping? A report of two cases and literature review.

Anterior communicating artery (AComA) aneurysm accompanied by visual symptoms is rarely reported. The first case is an asymptomatic 65-year-old woman who presented with an AComA aneurysm, and the pre-procedure high-resolution magnetic resonance imaging (MRI) revealed an AComA aneurysm compressed the left optic nerve and the chiasma with a size of 8.3 × 9.2 mm. She suffered a sudden onset of left eye visual loss and the temporal hemianopia of the right eye after endovascular embolization. She had a light sensation of the left eye and minor enlargement of the visual field in the right eye at the six-month follow-up. The second case is a symptomatic 55-year-old woman suffering a visual loss in the left eye and inferior nasal quadrantanopsia in her right eye. Pre-operative high-resolution MRI found an AComA aneurysm compressing the left part of the chiasma with a size of 7.1 × 8.3 mm. Her visual symptoms improved after surgical clipping. High-resolution MRI could depict the anatomic relationship between the AComA aneurysm and the surrounding optic pathways. Endovascular treatment of an AComA aneurysm may result in visual deterioration due to the mass effect or ischemia after the procedure. Surgical clipping of the AComA aneurysm could relieve the compression symptoms.