Background Endovascular treatment of middle cerebral artery (MCA)
aneurysms has traditionally been considered difficult due to complex branching patterns, frequent involvement of parent vessels within the
aneurysm neck, and a high incidence of thromboembolic complications. Methods The cases of 93 MCA
aneurysms treated with endovascular intervention at our institution between 2003 and 2015 were retrospectively reviewed. Demographic, clinical, and radiographic variables were recorded and analyzed. Results Immediate complete or near-complete occlusion was achieved in 81 (90%) cases. At the longest follow up of 6 months or greater, 83.3% of the
aneurysms were stable-to-improved in the Raymond occlusion classification, 8.3% were found to have minor recanalization not requiring
retreatment, and 8.3% required
retreatment due to significant recanalization. Thromboembolic events occurred in 18 (19.3%) of cases, but only 1 resulted in permanent vessel occlusion and only 1 resulted in permanent neurologic impairment.
Thrombus was resolved with intra-arterial thrombolysis or mechanical
thrombectomy in 17 of the 18 cases. There were only two cases resulting in morbidity (2.15%). There was no statistically significant correlation between
aneurysm location, size, morphology, or use of adjuvant device with radiographic outcome or thromboembolic event. Conclusions While the rate of thromboembolic events in our series was 19%, the overall morbidity was only 2%. This highlights the fact that even complex MCA
aneurysms can safely and effectively be treated by endovascular means with or without the use of balloon or
stent assistance, as long as the interventionalist is astutely aware of the possibility of
thrombus formation and acts accordingly with
thrombolytic therapy when necessary.