Comparison of Long and Short Stent Retrievers in Mechanical Thrombectomy for Acute Ischemic Stroke Due to Large Vessel Occlusion: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES: Longer stent retrievers (SRs) may improve clot integration and increase first-pass reperfusion in large vessel occlusions. However, their association with higher complication rates, including intracranial hemorrhage (ICH), remains uncertain. This study evaluated the impact of SR length on angiographic and clinical outcomes in acute ischemic stroke patients undergoing mechanical thrombectomy. METHODS: A systematic search was conducted in PubMed, Scopus, and Web of Science to identify studies comparing short (≤20 mm) vs long (>20 mm) SRs in mechanical thrombectomy for large vessel occlusion. Efficacy outcomes included first-pass complete reperfusion, first-pass successful reperfusion, final complete reperfusion, and final successful reperfusion. Safety outcomes included good clinical outcome (modified Rankin Scale 0-2 at 90 days), any ICH, symptomatic ICH, subarachnoid hemorrhage, emboli to new territory, vasospasm, and 90-day mortality. Pooled risk ratios (RRs) with 95% CIs were calculated under a random-effects model. RESULTS: Eight retrospective cohort studies (4545 patients; 2280 short SRs, 2265 long SRs) were included. Long SRs increased first-pass complete reperfusion (RR 1.14; CI 1.02-1.26), first-pass successful reperfusion (RR 1.13; CI 1.02-1.24), and final complete reperfusion (RR 1.09; CI 1.01-1.17). No significant differences were observed for final successful reperfusion (RR 0.95; CI 0.81-1.12), good clinical outcome (RR 0.96; 95% CI 0.88-1.04), any ICH (RR 0.87; 95% CI 0.34-2.21), symptomatic ICH (RR 1.11; 95% CI 0.43-2.84), subarachnoid hemorrhage (RR 0.99; 95% CI 0.62-1.56), emboli to new territory (RR 0.55; 95% CI 0.16-1.85), vasospasm (RR 0.84; 95% CI 0.50-1.42), or mortality (RR 1.08; 95% CI 0.88-1.32). CONCLUSION: Longer SRs improve angiographic efficacy, particularly first-pass reperfusion, without increasing overall complication rates. Their use should be tailored to thrombus burden and vascular anatomy, while future trials must refine criteria for optimal SR selection.