Endovascular coil embolization of anterior choroidal artery aneurysms

Object. Anterior choroidal artery (AChA) aneurysms are difficult to treat, and the clinical outcome of patients is occasionally compromised by ischemic complications after clipping operations. The purpose of this study was to document the outcome and follow-up results of endovascular coil embolization in patients with AChA aneurysms. Methods. Between July 1999 and March 2008, 88 patients with 90 AChA aneurysms ( 31 ruptured and 59 unruptured aneurysms) were treated with endovascular coil embolization in 91 sessions. There were 87 small aneurysms (< 10 mm) and 3 large aneurysms, with a mean aneurysm volume of 60.9 +/- 83.3 mm(3). Preprocedural oculomotor nerve palsy associated with AChA aneurysms was noted in 8 patients. Efficacy and safety were evaluated based on the degree of initial occlusion, procedure-related complications, patient outcome based on the Glasgow Outcome Scale score, and follow-up results. Results. The degree of angiographic occlusion of the aneurysms was complete for 15 aneurysms (17%), near complete for 69 aneurysms (77%) and partial for 6 aneurysms (7%). There were 4 (4.4%) symptomatic procedure-related complications ( 3 thromboembolic events and 1 procedural hemorrhage). The procedural hemorrhage resulted in death; however, the thromboembolic events only caused transient deficits. A favorable outcome ( Glasgow Outcome Scale score of 5 or 4) was achieved in 90% ( 79 of 88) of the patients at the time of discharge. No patient showed signs of bleeding or rebleeding during the follow-up period ( mean 25 months). Major aneurysm recanalization occurred in 2 cases. The AChA aneurysm-associated oculomotor nerve palsy tended to become aggravated transiently after coil embolization and then completely recovered over the course of 2-9 months. Conclusions. Coil embolization is a safe and effective treatment modality in cases of AChA aneurysms. Coil embolization enables procedural recognition of arterial compromise and immediate reestablishment of flow, thus contributing to a favorable outcome. (DOI: 10.3171/2009.4.JNS08934)