Emergency reversal of Rivaroxaban with Andexanet alfa in a child with hemorrhagic brain metastasis from Wilms tumor

BACKGROUND: Central nervous system (CNS) metastases from Wilms tumor (WT) are exceedingly rare. Intracerebral hemorrhage secondary to metastatic WT is even less common, and the management of such cases is further complicated when patients are receiving a direct oral anticoagulant (DOAC) like Rivaroxaban, for which pediatric reversal guidelines are lacking. CASE PRESENTATION: We report on the case of a 5-year-old boy with relapsed stage IV Wilms tumor who presented with rapidly progressive neurological deterioration caused by brain metastases with extensive intraparenchymal and intraventricular hemorrhage while receiving Rivaroxaban due to prior thrombosis. An emergent craniotomy and tumor resection was safely performed after emergent reversal of anticoagulation with Rivaroxaban using Andexanet alfa, administered in this pediatric patient with off-label consent in the setting of a life-threatening intracranial hemorrhage requiring emergent neurosurgical intervention. No excessive intraoperative bleeding was noted. Treatment for relapsed WT according to the SIOP-UMBRELLA-Protocol was initiated. Three weeks after Andexanet alfa treatment, a thrombotic event in the left iliac veins occurred, requiring anticoagulation with unfractionated heparin. CONCLUSIONS: This case highlights the therapeutic challenges of managing intracranial hemorrhage in a pediatric patient requiring emergent neurosurgical debulking in the setting of Rivaroxaban anticoagulation. To our knowledge, this is the second case reporting on Rivaroxaban reversal through Andexanet alfa in children. Early multidisciplinary intervention, meticulous neurosurgical management and continuation of oncologic therapy can lead to favorable outcomes even in such complex presentations.