Secondary embolization of a Helex occluder implanted into a secundum atrial septal defect

We report on a 2-year-old patient with atrial septal defect with a stretched diameter of 11 mm. The defect was closed uneventfully by use of a 25 mm Helex device. There was only trivial residual shunting (1 mm at the cranial margin of the device). After 36 hr, routine postinterventional echocardiography confirmed device embolization into the pulmonary artery. The child was asymptomatic. Transcatheter device retrieval with snares of different sizes, bioptomes, and retrieval forceps failed due to the mismatch of the diameter of the device and the small diameter of the pulmonary artery. Therefore, the device was retrieved surgically and the ASD closed by primary sutures. Secondary embolization of a Helex device complicated the closure of an uncomplicated atrial septal defect with a device-to-defect ratio according to the manufacturer's suggestion due to a mechanism not yet understood.