Introduction A significant number of patients with acute ischemic stroke (AIS) due to medium vessel occlusion (MeVO) fail to achieve favourable functional outcomes despite the best medical treatment (BMT) currently available. The efficacy and safety of Endovascular treatment (EVT) in strokes with underlying MeVO remain uncertain, with recent randomized controlled trials (RCTs) showing no clear benefit. This meta-analysis evaluates the combined impact of these studies on efficacy and safety of EVT in MeVO patients.

Materials and methods A systematic review and meta-analysis was conducted of randomized controlled trials (RCTs) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A comprehensive search was conducted in five online databases, including PubMed, Scopus, EMBASE, MEDLINE and Google Scholar from inception until March 2, 2025. The primary efficacy outcome was the relative risk (RR) of excellent functional outcome, defined as mRS 0-1 at 90 days. Secondary outcomes encompassed functional independence, defined as mRS 0-2 at 90 days, alongside the primary safety outcome, which was the risk of symptomatic intracerebral hemorrhage (sICH). Other safety outcomes included serious adverse events (SAEs) and deaths.

Results We included two RCTs (DISTAL and ESCAPE MeVO) involving 1,073 participants (526, EVT+BMT-arm and 547, BMT-arm). The pooled RR implied no significant difference between the two treatment arms; RR for primary efficacy outcome (mRS 0-1) was 0.95 (95% CI: 0.81-1.10) I2= 0%; for secondary efficacy outcome (mRS 0-2) was 0.98 (95% CI: 0.88-0.09) I2= 10%. The EVT+BMT-arm demonstrated a higher risk of sICH (RR: 2.39, 95% CI 1.26-4.53) I2= 0% and SAE (RR: 1.32, 95% CI 1.11-1.56) I2= 0%, while mortality at 90 days (RR: 1.29, 95% CI 0.94-1.76) I2=16% showed no significant difference. Trial sequential analysis revealed that for primary efficacy outcome (mRS 0-1), the z line lies in the futility zone (acquired information size AIS 96%, 1069 patients).

Conclusion Our study showed that, in patients with AIS due to MeVO, EVT did not lead to better outcomes at 90 days when compared to BMT and was associated with a higher risk of sICH and SAEs compared to usual care, and this result was confirmed in a TSA analysis.

The authors have declared no competing interest.

This study did not receive any funding

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