Impact of Aneurysmal Neck Position in Endovascular Therapy for Anterior Communicating Artery Aneurysms.

Anterior communicating artery (ACoA) aneurysms have a complex architecture and many variations, making endovascular therapy more difficult in some cases. The aim of this study was to investigate whether the neck position of an aneurysm was identifiable for determining the immediate angiographic success and procedural complications in the coiling of the ACoA aneurysms. We conducted a retrospective case review of 40 patients with ACoA aneurysms treated by endovascular therapy from 2008 to 2015. The mean age was 66.8 years. Thirty-five aneurysms were ruptured; five were unruptured. For the analysis, the patients were divided into two groups according to the neck position of aneurysms: the true ACoA group, 9 patients with the neck located on the ACoA itself; and the other ACoA group, 31 patients with the neck at the junction of the A1 and A2 portions of an anterior cerebral artery. Morphological characteristics (dome size, dome direction, rate of wide neck, and angulation of aneurysms in relation to the parent artery) were analyzed along with immediate angiographic results, volume embolization ratio (VER), and procedural complications. Small aneurysms with superior dome projection and acute angulation of the aneurysm direction occurred more often in the true ACoA group. The rates of complete obliteration, VER, and procedural complications were 33.3%, 32.3%, and 22.2% in the true ACoA group and 54.8%, 36.3%, and 6.5% in the other ACoA group, respectively. True ACoA aneurysms could present an anatomical difficulty in endovascular coiling. Aneurysmal neck position should be accurately assessed to achieve successful embolization of the ACoA aneurysms.