Acute Mechanical Mitral Valve Thrombosis Treated by Endovascular Recombinant Tissue Plasminogen Activator in a 2-Year-Old.

BACKGROUND: Mechanical mitral valve thrombosis in early childhood is rare, and its acute management is challenging. CASE SUMMARY: A 2-year-old girl with Shone complex and multiple prior mitral valvuloplasties developed obstructive thrombosis 20 days after inverted Saint-Jude mechanical valve implantation (mean mitral gradient 26.75 mm Hg). Given multiple previous sternotomies and hemodynamic stability, catheter-directed, continuous low-dose alteplase was infused into the left atrium with a catheter positioned into the left inferior pulmonary vein (0.045 mg/kg/h; then 0.1 mg/kg/h) under uninterrupted heparinization. Leaflet mobility improved within 48 hours, with complete thrombus resolution and no hemorrhagic complications. DISCUSSION: This case illustrates that continuous, low-dose local thrombolysis with alteplase may be a safe and effective alternative for mechanical mitral valve thrombosis in pediatric patients, especially those with elevated surgical risks. TAKE-HOME MESSAGE: Catheter-directed, continuous low-dose alteplase can promptly restore prosthetic mitral valve function in stable pediatric patients, provided strict monitoring and anticoagulation stewardship.