C53 Ticagrelor-induced thrombocytopenia complicating flow diversion of a cerebral aneurysm in a pediatric patient

<h3>Introduction</h3> Dual antiplatelet (DAPT) strategies following intracranial flow diversion procedures are recommended for preventing thromboembolic and hemorrhagic complications. Ticagrelor is an oral and reversible P2Y12 antagonist, generally well tolerated and commonly used, particularly in patients with Clopidogrel resistance, due to the higher risk of ischemic events. Ticagrelor-induced thrombocytopenia is a rare but potentially life-threatening complication that requires prompt recognition and management. <h3>Case Description</h3> We report the case of a 15-year-old male with history of sickle cell disease, chronic anemia and G6PD deficiency. Due to headache and crural right hemiparesis, brain MRI and MRA revealed sequelar ischemic lesions of the left lenticular nucleus and a right carotid cave saccular aneurysm (4x4mm). After a 5-day DAPT regimen with Aspirin and Ticagrelor, the right carotid cave aneurysm was treated with a flow-diverter stent. DAPT was prescribed for 3 months. On the day prior to the procedure, mild neutropenia and thrombocytopenia were noted and hydroxyurea was suspended. During the following days, neutrophil count returned to normal, but platelet count gradually decreased, reaching a nadir of 14x10⁹/L on the third day post-procedure. Antiplatelet-induced thrombocytopenia was considered, and Ticagrelor was switched for Clopidogrel. Platelet transfusion and high-dose prednisolone was started to suppress a potential immune-mediated process. Platelet count increased on the next days to normal values. <h3>Conclusions</h3> This case emphasizes thrombocytopenia as a rare side effect of Ticagrelor and asserts its implications in the management of patients submitted to intracranial flow-diverter treatment. <h3>Conflict of Interest</h3> No