脳動脈瘤コイル塞栓2年以後の塞栓状態の画像上変化

Abstract

In this study, we evaluated the embolic state based on imaging findings two years after embolization, and divided our patients into groups to examine postoperative changes in imaging findings. We studied 61 patients with cerebral aneurysms who underwent embolization in our hospital. There were 23 males and 38 females (mean age 60.6 y) with 66 aneurysms (16 ruptured and 50 unruptured). Embolic state was evaluated two years after treatment, and subsequent imaging-based follow-up with MR angiography was continued for six months or more. The follow-up period ranged from 30 to 146 months after embolization (median: 49, mean: 63). Based on the embolic state two years after coil embolization, the aneurysms were divided into three groups: complete occlusion (C group), neck remnant (N group), and body filling (B group) groups. Changes in the embolic state at the final evaluation point were investigated. Two years after embolization, 39 aneurysms were assigned to C group, 21 to N group, and six to B group. According to the final results, complete occlusion was noted in 37 aneurysms (94.8%) in C group, neck remnants in 18 (85.7%) in N group, and body filling in six (100%, additional treatment: 1) in B group; there were no changes in comparison with the results two years after embolization. We compared the results between ruptured and unruptured groups. In the former, there were no changes in 13 aneurysms, improvement was achieved in one, and deterioration was noted in two. In the latter, there were no changes in 47 aneurysms, improvement was achieved in two, and deterioration was noted in one (additional treatment: one aneurysm); there were no differences. With respect to the aneurysmal size, there were no differences in the results among three groups with a capacity of ＜100 mm3 (41 aneurysms), 100 to 200 mm3 (nine aneurysms), and ≧200 mm3 (nine aneurysms). With respect to the volume embolic ratio (VER), there were also no differences among three groups with a VER of ＜20% (14 aneurysms), 20 to 30% (25 aneurysms), and ≧30% (21 aneurysms). There were no changes in imaging findings two years or more after the coil embolization of cerebral aneurysms. The long-term result was very favorable regardless of the presence or absence of rupture, aneurysmal capacity, and VER. However, long-term follow-up was possible in only a small number of patients in specific groups, consisting of body filling or ruptured aneurysms; a larger number of patients should be investigated in the future.