Changes in coil morphology following transcatheter coil occlusion of the patent ductus arteriosus using a modified snare technique.

We observed a decrease in length of the Gianturco coils following transcatheter occlusion of the patent ductus arteriosus (PDA). Coil length was measured on chest radiograph within 24 hr of coil placement and compared to the length at the time of follow-up. Echocardiograms were also reviewed for evidence of duct recanalization. Twenty-seven patients met inclusion criteria. The median time to follow-up was 5 months (1--12 months). Twenty-four out of 27 (89%) patients had a decrease in coil length by 1.9 +/- 1.1 mm (P < 0.01). This was an average decrease of 16%. One patient had an increase in length and two patients had no change in coil length. Nineteen out of 27 patients had echocardiograms. Despite the change in coil length, there was no evidence of flow acceleration in the pulmonary artery or descending aorta. No patients had evidence of duct recanalization.