Endovascular Treatment of a Ruptured Distal Anterior Choroidal Artery Aneurysm Associated with Ipsilateral Posterior Cerebral Artery Occlusion

Abstract

This report describes a rare case of a ruptured aneurysm in a branch of the distal anterior choroidal artery (AChA), occurring after occlusion of the ipsilateral posterior cerebral artery (PCA). A 69-year-old male who had been monitored for a thrombosed PCA aneurysm presented 2 years later with sudden severe headache and nausea. Computed tomography (CT) revealed subarachnoid and intraventricular hemorrhage, and digital subtraction angiography identified an aneurysm in a branch from the AChA cisternal segment. Owing to difficult catheter access and high risk of reflux with N-butyl cyanoacrylate (NBCA) embolization, parent artery occlusion (PAO) using detachable coils was performed. Postoperative magnetic resonance imaging (MRI) showed a small right posterior limb of the internal capsule infarction, but no worsening of neurological deficits occurred. The patient was transferred for rehabilitation with a modified Rankin Scale score of 4. Distal AChA aneurysms are extremely rare, especially those arising from the cisternal segment, and typically develop due to hemodynamic stress from collateral circulation. This case highlights PAO with coils as an effective and feasible endovascular treatment. Further accumulation of such cases is necessary to establish optimal treatment strategies.