Late-onset infective endocarditis after transcatheter atrial septal defect device closure involving mechanical factors: a case report.

Late-onset infective endocarditis after transcatheter atrial septal defect device closure is uncommon, and in selected patients, mechanical factors related to adverse device-tissue interaction may contribute to the development of late device-related infection. A 15-year-old boy presented with fever and systemic embolic manifestations eight years after transcatheter atrial septal defect closure. Echocardiography demonstrated a mobile mass on the left atrial surface of the occluder device, and computed tomography revealed splenic infarction and a mass-like lesion adjacent to the right lower pulmonary vein orifice. Emergent surgical intervention revealed extensive vegetation and fibrotic thickening predominantly along the right lower pulmonary vein orifice-adjacent left atrial wall, rather than on the device surface. The device was removed, the defect was closed using an autologous pericardial patch, and the patient completed six weeks of antibiotic therapy with an uneventful recovery. This case suggests that incomplete endothelialisation and chronic device-related mechanical interaction may create a vulnerable endocardial environment that facilitates bacterial adherence and subsequent infective endocarditis. Careful patient selection, prudent device sizing, and long-term echocardiographic surveillance may help identify patients in whom consideration of antibiotic prophylaxis during exposure to transient bacteremia could reduce the risk of subsequent infective endocarditis.