Endovascular treatment (EVT) for acute ischemic stroke due to M2 segment middle cerebral artery occlusion remains technically challenging and underrepresented in randomized trials. The relative efficacy and safety of different EVT techniques, such as the stent retriever (SR), direct aspiration (DA), and combined techniques (DA+SR), are not well understood.
A systematic review and NMA were conducted following PRISMA-NMA guidelines. We searched databases through March 2025 for eligible studies comparing angiographic, functional, and safety outcomes between different EVT techniques. We performed a frequentist NMA using the “netmeta” package in R v4.4.1. Risk ratios (RR) along with 95% CIs were pooled using a random effects model. Treatment rankings were performed using surface under the cumulative ranking (SUCRA) probabilities. Network consistency was assessed using node-splitting and Gelman-Rubin diagnostics. Heterogeneity and consistency were evaluated using standard metrics.
Twelve studies, including 2,741 patients, met the inclusion criteria. All models demonstrated good convergence with minimal inconsistency. SUCRA scores suggested potential advantages of DA+SR for successful and excellent recanalization, DA for first-pass effect and lower subarachnoid hemorrhage risk, and SR for complete recanalization and lower sICH risk. However, none of the pairwise comparisons reached statistical significance. Although SUCRA scores suggested a potential disadvantage of DA (26.6%) for achieving functional independence at 90 days (mRS 0–2) when compared to SR (61.7%) and DA+SR (61.6%), the pairwise comparison did not reveal statistical significance. No significant differences observed in safety outcomes, including parenchymal hematomas and 90-day mortality, across techniques.
This meta-analysis demonstrates that all techniques offer comparable efficacy and safety in the treatment of M2 occlusions. Given the potential time and cost savings of not using a combined technique, these results may encourage the use of SR or DA alone as first-line techniques for M2 thrombectomy.