Middle cerebral artery dissecting aneurysms: A systematic review of presentation, etiology, and prognosis

Dissecting aneurysms of the middle cerebral artery (MCA) are rare, under-recognized vascular lesions with diverse etiologies and complex management pathways. The current literature is fragmented, lacking a consensus on optimal treatment and outcome predictors. This study aims to systematically review and synthesize all reported cases of MCA dissecting aneurysms, analyzing clinical features, anatomical patterns, therapeutic strategies, and outcomes.

A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Comprehensive literature searches were performed across PubMed and Scopus databases up to June 2024. Crude estimates are reported, and meta-analysis is also performed.

From 878 records, 65 studies (1964-2025) met criteria, totaling 114 MCA dissecting aneurysm/pseudoaneurysm patients (mean age ≈42.8 years; pediatric 8.8%; female 54%). Hypertension (12.3%) and prior head trauma (9.6%) were common. Aneurysms most often involved M1 (38.6%), then M2 (29.8%), and M3-M4 (31.6%); right-sided 34.2%. Management was endovascular in 59 (51.8%), microsurgical in 38 (33.3%), bypass in 12 (10.5%), and conservative in 17 (15%). Overall, good outcome (modified Rankin scale: 0-2) occurred in 56 (49.1%); complete occlusion in 73 (64%); and rebleeding and mortality each 11 (9.6%). Meta-analysis showed higher occlusion with endovascular therapy (62%, 95% confidence interval [CI]: 0.46-0.77; P < 0.001) versus surgery (36%, 95% CI: 0.08-0.64; P = 0.012), with markedly higher surgical rebleeding (55%) and mortality (45%).

Reported outcomes of MCA dissecting aneurysms show that aneurysm occlusion is achievable with both endovascular and surgical strategies, but interpretation is limited by heterogeneity and mostly case-based data evidence.