Risk Factors after Reduction to Single Antiplatelet Therapy for Postoperative Ischemia of Intracranial Stent-assisted Coil Embolization

Objective: There are concerns regarding ischemic events associated with stent-assisted coil embolization. It is important to evaluate the risk factors for delayed thromboembolic events. This study evaluated risk factors after reduction to single-antiplatelet therapy 140–365 days after embolization.Methods: We conducted a retrospective and cross-sectional study of patients who underwent stent-assisted coil embolization. Sixty eight aneurysms in 67 patients with unruptured intracranial aneurysms or the chronic phase of ruptured intracranial aneurysms between July 2010 and April 2014 were evaluated.Results: Dual-antiplatelet therapy was administered for 157 ± 65 days. Three patients who were administered the single-antiplatelet agent experienced postoperative ischemic events. One patient experienced cerebral infarction 143 days after the procedure. One patient with over 50% in-stent stenosis experienced cerebral infarction 194 days after the procedure. The final patient experienced transient ischemic attack (TIA) 223 days after the procedure, and re-embolization was performed 209 days after the procedure. Postoperative ischemic events occurred more frequently in severe in-stent stenosis patient (P