Successful surgical palliation with the Fontan procedure allows survival into adulthood for many patients born with single ventricle (SV) physiology, but the limited studies reported incidence of perioperative and long-term complications including thromboembolic events. Chronic pulmonary embolism is a common complication in patients with Fontan circulation, and may have serious consequences. Percutaneous intervention may be less invasive option for such a high-risk population than surgery is. We described two patients who developed complete thrombosis of the left pulmonary artery following catheter placement of a stent in this vessel shortly after Fontan surgery. Percutaneous catheter aspiration thrombectomy was successfully performed. Percutaneous catheter aspiration thrombectomy may be considered as a viable option in acute thrombus in children with SV physiology after Fontan surgery. (c) 2014 Wiley Periodicals, Inc.