Postoperative cytotoxic cerebral edema following surgical resection of a giant right atrial aneurysm in an infant: a rare case report.

This case report describes a rare case of a giant right atrial aneurysm (RAA) in a 7-month-old male infant admitted to Children's Hospital Affiliated to Zhengzhou University in July 2025. A RAA was detected during a physical examination at 2 months of age with no clinical symptoms present. Follow-up reexamination at 7 months of age revealed progressive enlargement of the RAA, and the infant thus underwent aneurysm resection plus atrial septal defect repair under cardiopulmonary bypass. Postoperative histopathological examination confirmed the diagnosis of RAA. On the second postoperative day, the infant developed neurological complications including lethargy, skew deviation, mild hemiplegia, and focal epilepsy. The hospital immediately implemented a multimodal intervention strategy involving mannitol for dehydration, glucocorticoids for anti-inflammation, antiepileptic medication, and strict fluid management. The infant achieved near-complete recovery of neurological function at discharge on the 21st postoperative day, with significant improvement in brain abnormalities on follow-up at 1 month postoperatively. This case highlights cytotoxic cerebral edema, a rare postoperative neurological complication following RAA resection in children, and emphasizes the importance of early identification and multimodal treatment for such complications, providing valuable clinical evidence for the perioperative management of pediatric cardiac surgery.