Endovascular thrombectomy for medium vessel occlusion stroke shows favorable outcomes in observational studiesEndovascular Thrombectomy Shows Potential for Medium Vessel Occlusion Stroke

BackgroundMedium vessel occlusions (MeVOs) account for 25–40% of acute ischemic strokes and present a significant therapeutic frontier. Despite high technical success rates of endovascular thrombectomy (EVT), recent randomized trial results have been nuanced, creating a paradox and underscoring the need for a precision-based approach.MethodsWe conducted a systematic review following PRISMA guidelines. After screening, 42 original studies were included (4 RCTs and 38 cohort studies). Evidence was synthesized and appraised using a three-tiered hierarchy. The GRADE framework was applied. Overall certainty of evidence ranged from moderate to very low.ResultsObservational studies, which often enrolled populations with higher baseline NIHSS scores and stricter imaging selection criteria, generally reported favorable functional independence rates (mRS 0–2 in 60–80% of EVT-treated patients). However, these rates may partly reflect selection bias rather than a purely treatment-related effect. Successful recanalization is frequently achieved (>85%), but safety concerns like symptomatic hemorrhage and vessel perforation require careful management. Success hinges on a precision strategy integrating advanced imaging (e.g., CT perfusion for “Target Mismatch”) with a tailored technical arsenal. This includes dedicated low-profile stent retrievers and aspiration catheters, selected based on occlusion site, thrombus burden, and anatomy. A “Eight Keys” framework interprets neutral trial results, highlighting patient selection heterogeneity. Future progress depends on refined imaging criteria, dedicated device development, and validated selection tools.ConclusionCurrent randomized evidence does not demonstrate an overall functional benefit of endovascular thrombectomy (EVT) for unselected MeVO stroke, while procedure-related hemorrhagic risk appears higher than with best medical therapy. EVT may be reasonable in carefully selected patients with disabling deficits, salvageable tissue, and favorable anatomy, when performed by experienced teams using distal-appropriate techniques. Future work should prioritize validated selection tools, standardized imaging definitions, distal-specific devices, and trial designs enriched for patients most likely to benefit.