Evolving role of endovascular treatment for MCA bifurcation aneurysms: case series of 184 aneurysms and review of the literature

Objective: This study evaluates the role of endovascular therapy for middle cerebral artery (MCA) aneurysms and its evolution over time. We are reporting a large case series of 184 MCA aneurysms and comparative analysis of the literature. Methods: This was a retrospective review of a prospectively maintained database including all patients with MCA bifurcation aneurysms embolized between 2000 and 2013. There were 184 aneurysms in 166 patients, with 71 ruptured and 113 nonruptured aneurysms. Results: Stent assistance was required in 70 cases (38.0%) and 3 cases (1.6%) required 'Y' stenting. The initial rate of total aneurysmocclusion was 59.8% and at delayed follow up was 90.1%. Seven embolizations resulted in thrombo-embolic complications (3.8%), with no cases of aneurysm re-bleeding, wire perforations, or other hemorrhages. Three patients with ruptured aneurysms died of causes unrelated to the embolization, and none with nonruptured aneurysms died in the follow-up period (total mortality 1.6% at 30 days post-procedure). A total of seven aneurysms (3.9%) required retreatment with an average follow up of 41 months. Prior to dedicated aneurysm stents, 68.8% of patients underwent embolization with the remainder surgically treated. Following the introduction of aneurysm stents in 2002, 92.0% of MCA aneurysms treated were embolized. Conclusions: During the past decade we have seen a treatment paradigm shift in MCA aneurysm treatment from surgical treatment to endovascular treatment. Developments in 3D angiography, more compliant balloons, dedicated aneurysm stents, complex coils, and antiplatelet therapy regimes have led to this transition for safe and effective management of these patients.