Antiplatelet Therapy after Endovascular Intracranial Aneurysm Surgery: Comparative Effectiveness and Safety Insights from Systematic Review and Meta-Analysis

INTRODUCTION: Endovascular treatment of intracranial aneurysms - particularly stent-assisted coiling and flow diversion (FD) - requires antiplatelet (AP) therapy to prevent thromboembolic complications. However, standard fixed-dose regimens may not account for individual variability in drug response or device-specific thrombogenicity. This systematic review and meta-analysis evaluate the comparative effectiveness and safety of tailored AP protocols versus standard regimens. METHODS: A comprehensive search of PubMed, Embase, and Cochrane Library identified 27 eligible studies (n = 8,452 patients) comparing tailored AP strategies - including platelet function testing (PFT)-guided adjustments, potent P2Y12 inhibitors, and surface-modified device protocols - with standard dual AP therapy. Primary outcomes were thromboembolic events and major hemorrhage within 30 days. Meta-analysis was performed using a random-effects model with a 2× scaling factor and 1.0 continuity correction to address zero-event cells ("Khanafer effect"). Subgroup and trial sequential analyses (TSAs) were conducted to assess robustness and certainty. RESULTS: Tailored AP protocols significantly reduced thromboembolic events (RR 0.45; 95% CI: 0.37-0.54; p < 0.001), with TSA confirming adequate information size. Major hemorrhage was also reduced (RR 0.52; 95% CI: 0.32-0.83; p < 0.05), though heterogeneity was high (I2 = 77.5%). Subgroup analysis revealed the greatest benefit in surface-modified FD using single antiplatelet therapy (SAPT) (RR 0.06 for ischemia; RR 0.11 for hemorrhage). Tailored clopidogrel (PFT-guided) and potent P2Y12 inhibitors (prasugrel/ticagrelor) both demonstrated superior ischemic protection without increasing bleeding risk. Efficacy was consistent across ruptured and unruptured aneurysm cohorts. CONCLUSIONS: Tailored AP therapy significantly improves ischemic outcomes without compromising safety in patients undergoing endovascular aneurysm treatment. Surface-modified devices enabling SAPT offer a promising evolution in neurointerventional care. These findings support a shift from fixed-dose regimens toward personalized protocols informed by platelet biology and device technology. Further large-scale trials are warranted to standardize individualized AP strategies into clinical guidelines.