Antiplatelet regimen following stent-assisted embolization for intracranial aneurysms

Abstract

Objective To investigate the efficacy and safety of one antiplatelet regimen following stent-assisted embolization for intracranial aneurysms. Methods Clinical data were analyzed retrospectively in 684 patients with intracranial aneurysms who underwent stent-assisted embolization from July 2014 to July 2016 at Wuhan General Hospital of the Chinese Liberation Army. Tirofiban hydrochloride was injected immediately after stent deploying and infused continuously by micro-pump for 24 hours. Dual antiplatelet therapy (aspirin 100 mg/d + clopidogrel 75 mg/d) started on the second day. Postoperatively, the platelet activation function was dynamically monitored by flow cytometry. The dose adjustment criteria of antiplatelet drugs were based on the platelet inhibition status (the positive rate of CD62P after adenosine diphosphate activation was below 20%) and specific postoperative conditions such as hemorrhage or ischemia for 486 cases (passive adjustment group) before June 2015, and those for 198 cases (active adjustment group) after June 2015 were only according to the platelet inhibition status regardless of hemorrhage or ischemia. Results Complications were reported in 67 out of 684 (9.8%) cases and included aneurysm rerupture (n=23, 3.4%), hydrocephalus requiring ventriculoperitoneal shunting (n=13, 1.9%), stent thrombosis (n=9, 1.3%), cerebral infarction (n=6, 0.9%), intracranial hemorrhage in remote areas (n=4, 0.6%), plaque shedding (n=2, 0.3%) cases, aneurysm recurrence (n=3, 0.4%) and death (n=26, 3.8%). The medication regimen was adjusted in a total of 221 (32.3%) patients including 147 (30.2%, 147/486) cases in the passive adjustment group and 74 (37.4%, 74/198) cases in the active adjustment group. There was significant difference in the complication rate of hemorrhage between passive and active adjustment groups (9.1% [44/486] vs. 3.5% [7/198], P<0.05). No significant difference was identified in the complication rate of ischemia between the two groups (0.2% [1/462] vs. 1.0% [2/196], P=0.19). Transient ischemic attack occurred in 3 (0.4%) cases during the process of dose reduction of clopidogrel which remitted following the dose increase. No case of resistance to antiplatelet therapy was found. Conclusion Antiplatelet therapy regimen guided by platelet activation assay could be useful for preventing thrombosis and hemorrhagic events following stent-assisted embolization for intracranial aneurysms. Key words: Intracranial aneurysm; Aneurysm, ruptured; Embolization, therapeutic; Stents; Platelet aggregation inhibitors; Coil