Methods and resultsTo assess the safety and efficacy of the device, we performed a prospective clinical study between June, 2009 and December, 2010 in La Paz, Bolivia. In all, 29 – 22 female patients and 7 male patients – out of 59 patients were selected on the basis of inclusion criteria. The procedures were performed under sedation at an age and weight of 5.7 years and 22.7 kilograms, respectively, with 4–6 French arterial sheaths and 5–7 French venous sheaths. The minimal diameter of the duct was 3.5 millimetres. The procedure, fluoroscopy, and hospitalisation times were 96.4 minutes (55 to 145), 13.1 minutes (3 to 25.2), and 24 hours, respectively. The “Nit-Occlud® PDA-R” was successfully deployed in all patients. Immediate, 24-hour, 1-, 3-, and 6-month closure rates were 65.5%, 79.3%, 96.5%, and 100%, respectively. The systolic pulmonary pressure diminished from 37 millimetres of mercury (21 to 57) before the intervention to 31 millimetres of mercury (21 to 45) after the intervention. No early or late embolisation, haemolysis, left pulmonary artery, or descending aorta obstruction occurred.