Anterior Choroidal Artery Aneurysm: Basal Ganglia AVM, Supplied by the Anterior Choroidal Artery, with an Intranidal Aneurysm; Targeted Embolization Prior to Radiosurgery

Abstract

A 30-year-old male patient presented with a sudden headache, followed by a minor left hemiparesis. Diagnostic imaging revealed a circumscribed right sided thalamic hematoma und an underlying brain arteriovenous malformation (bAVM) supplied by the anterior choroidal artery and perforators of the basilar artery with deep venous drainage. The bAVM nidus consisted of several feeding arteries of small caliber and two draining veins. An aneurysm with a diameter of 3 mm was identified on the posterior aspect of the bAVM nidus. The bAVM was not considered suitable for microsurgical resection due to the location of the nidus. Therefore, stereotactic radiosurgery was considered the most promising treatment strategy. Given the expected latency of 2–3 years between irradiation and bAVM vessel obliteration, the intranidal aneurysm was a concern. It was therefore excluded prior to radiosurgery by embolization using nBCA. The selective catheterization of the bAVM feeding artery carrying the intranidal aneurysm was straightforward. nBCA (Glubran 2, GEM) diluted with ethiodized oil (Lipiodol Ultra-Fluid, Guerbet) was slowly injected through the microcatheter. The solidified polymer cast occluded the intranidal aneurysm as well as the arterial vessel proximal and the transitional vessel segment distal to the aneurysm. The patient tolerated this procedure well and underwent stereotactic irradiation of the bAVM 10 days later. The significance and management of intranidal aneurysms in bAVMs are the main topics of this chapter.