Nelly Rocío Fabiani HurtadoAlexandra Heath‐FreudenthalInge von AlvenslebenGabriel EchazúFranz FreudenthalAbraham Rothman2026-03-222026-03-22202510.1017/s1047951125001726https://doi.org/10.1017/s1047951125001726https://andeanlibrary.org/handle/123456789/77101A 3-year-old girl with a large ductus arteriosus had increased pulmonary vascular resistance at cardiac catheterisation. Test occlusion of the ductus arteriosus with a Nit-Occlud PDA-R device and hyperoxia decreased the pulmonary arterial pressure to < 50% of systemic level. The ductus was closed with the same device. Two years later, an echocardiogram showed normal pulmonary arterial pressure.enDuctus arteriosusMedicineCardiologyInternal medicineVascular resistancePulmonary arterial pressureCardiac catheterizationOcclusionBlood pressurePulmonary arteryUse of a ductal occluder device as a test and then permanent closure of a large ductus arteriosus with increased pulmonary vascular resistance: a case reportarticle