中大脳動脈瘤の塞栓術は必要か？ ─未破裂中大脳動脈瘤塞栓術の適応と有用性について─

抄録

For treating middle cerebral artery (MCA) aneurysms, clipping is given more priority than coiling due to easier accessibility during craniotomy. We reviewed patients with unruptured MCA aneurysms treated with coil embolization in our hospital and investigated its safety and usefulness.

In total, 1, 386 patients with unruptured aneurysms were treated for 12 years. 86 patients (6.2%) with MCA aneurysms were included in this study. We focused on 53 patients (34 females; mean age, 66 years) who were treated after 2010, when various adjunctive techniques were established. Clinical results and complications were examined and compared with those patients in the early period before 2010.

All aneurysms with a maximum diameter of 3-10 mm (mean, 5.3 mm) were successfully treated with coil packing with the following: single microcatheter (22 patients), balloon-assisted technique (3 patients), stent-assisted technique (9 patients), and double catheter technique (19 patients). Angiographic results showed complete occlusion (24 patients, 45.3%), neck remnant (24 patients, 45.3%), and body filling (5 patients, 9.4%). We encountered two procedure-related complications due to branch occlusion, and one affected patient showed symptoms. Morbidity and mortality rates were 1.9% and 0%, respectively. Endovascular treatment was selected due to the following: patient preference (28 patients), poor general condition (8 patients), single-session treatment for multiple aneurysms (17 patients), and retreatment of a clipped aneurysm (1 patient). Compared with the results obtained during the early period, the rates of complete occlusion and favorable outcomes were higher in the latter period.

Generally, most unruptured MCA aneurysms have an extremely broad neck and direct branching pattern from the dome. This makes clipping difficult even for highly skilled surgeons. Additionally, unique situations require less invasive treatment, such as poor general condition, multiple aneurysms requiring multiple craniotomy sessions, and strong patient preference. Since results of endovascular treatment have improved owing to new adjunctive methods, its demand may increase.