Transcatheter occlusion of persistent patent ductus arteriosus (PDA) was attempted in 32 patients (22 female and 10 male, mean age 5.12 +/- 3.98 years, range 9 months to 19.2 years) using Rashkind's occluder device (USCI). Implantation of a second occluder device was attempted in three of the patients. Device embolization to a pulmonary artery occurred in three patients, all with the 12 mm occluder device; two of these devices were retrieved by grabber catheter and the last with thoracotomy without adverse sequelae. Embolization to the right atrium occurred in another patient during a second device implantation attempt because of fluoroscopy problems; this patient required open-heart surgery with sequala of 2 (+) tricuspid insufficiency. In another patient with a significant shunt after the implantation of a 17 mm occluder device, mechanical hemolysis developed, but surgical intervention was not required. The overall complication rate was five out of 35 implantation procedures (14.3%). Besides these, sublingual nifedipine was required for two patients whose systolic blood pressure exceeded 160 mmHg just after the implantation procedure. Sixteen 12 mm and fifteen 17 mm occluder devices were successfully and uneventfully implanted in the first procedure, except for two patients in whom a 17 mm occluder device was implanted after retrieval of an embolized 12 mm occluder. Overall early and mid-term complete occlusion was achieved in 24 patients (75%). Complete occlusion of PDA in the first days after the procedure was achieved in all patients, with the narrowest ductal diameter of less-than 3 mm with the 12 mm occluder device, and less than 6 mm with the 17 mm occluder device.(ABSTRACT TRUNCATED AT 250 WORDS)