In many cases of anterior choroidal artery aneurysms (IC-AChA An), anterior choroidal arteries (AChA) arise from the aneurysmal neck or dome. This is an important reason for a higher rate of surgical complications. We treated 29 cases of IC-AChA An between January 2006 and May 2010, and classified them based on the origin of AChA by retrospective investigation of preoperative 3D-DSA. Cases in which AChA mainly arose from internal carotid arteries were classified as Group 1, those from the aneurysmal neck were classified as Group 2, and those from the aneurysmal dome were classified as Group 3. Thare were 3 cases (10.3%) in Group 1, 21 cases (72.4%) in Group 2 and 5 cases (17.2%) in Group 3. The average of dome /neck ratio was 1.22. Clipping was performed with indocyanine green (ICG) videoangiography in 27 cases and motor evoked potential monitoring (MEP) in 18 cases. There were no ischemic lesions in MRI or neurological dysfunction after surgeries in any of the groups. In 3 of 18 cases with MEP—1 in Group 2 and 2 in Group 3—the amplitudes decreased. In 2 of the 3 cases, ICG videoangiography showed good blood flow. We should keep in mind that ICG videoangiography is not quantitative. ICG videoangiography is very useful, but MEP is routinely needed. Group 1 and Group 2 cases about 90% of all cases, require careful modification of the origin of AChA in clipping.
Understanding the origin of AChA using 3D-DSA before surgery is very important to realize good surgical results.
