Endovascular treatment of 346 middle cerebral artery aneurysms: results of a 16-year single-center experience.

The endovascular treatment of middle cerebral artery (MCA) aneurysms has been controversial because of the frequency of complex anatomy and the relative ease of surgical clipping in this location. To present a large single-center experience with the endovascular treatment of MCA aneurysms. The neurointerventional database at our institution was reviewed for all endovascular treatments of MCA aneurysms. Demographics, aneurysm characteristics, treatment modality, intraprocedural hemorrhagic and thromboembolic events, 30-day neurological events, and follow-up angiographic studies were recorded. From December 1996 to April 2013, 292 patients underwent endovascular treatment of 346 MCA aneurysms. Of these, 341 (98.6%) were successfully completed. Balloon neck remodeling was used in 230 procedures (66.5%). Ninety-five procedures (27.4%) were for ruptured aneurysms. The rate of intraprocedural hemorrhage was 2.6% (9 of 346). The overall rate of intraprocedural thromboembolic events was 13.6% (47 of 346), significantly more common in patients with acute subarachnoid hemorrhage (27.4%; P < .001). The 30-day major (modified Rankin Scale score > 2) neurological event rate was 2.9% (10 of 346), significantly more common in patients with subarachnoid hemorrhage (8.4%) compared with those without (0.8%; P < .001). The rate of complete or near-complete aneurysm occlusion at was 90.6% ≥ 6 months and 91.8% at ≥ 2 years, with an average of 24 months of follow-up available for 247 procedures. Endovascular treatment of MCA aneurysms can be safe and effective. However, it is associated with a high asymptomatic thromboembolic event rate that is more frequent in the setting of acute subarachnoid hemorrhage.