angle formed between patent ductus arteriosus and descending thoracic aorta in a beating heart: a helpful study to design a better device for occluding patent ductus arteriosus

Background: the percutaneous transcatheter closure of patent ductus arteriosus (pda) has been a widely used treatment method. however, pda device closure in neonates or patients with specific pda morphology has been difficult due to the protrusion of the device into the descending aorta. the right angle between the disc and plug causes some degree of protrusion of the disc into the descending aorta because normal pda forms an acute angle with the descending aorta. objectives: there have been limited data about the angles of pda since mancini’s study in 1951, and new studies are required in this regard. this study measured the angles between pda and descending aorta through angiography in a beating heart. methods: within december 2008 to november 2016, 190 patients undergoing percutaneous pda occlusion were included in this study. retrospectively, the mean angle of pda was measured by three cardiologists between the longitudinal axis of the descending aorta and the longitudinal axis of the pda through an aortogram. the patients were divided into three groups according to age (group a: under 1, group b: 1 - 6, and group c: over 6 years of age) and pda morphology based on krichenko’s classification (type a: conical pda, type b: window pda, type c: tubular pda, type d: complex pda, and type e: elongated pda). results: of 190 study patients, 135 patients were female, and the median age of the patients was 7 years (range: 75 days to 60 years). the mean angle of pda was 48.2±12.0°. there were no statistical differences regarding pda angle among the groups classified by age and pda morphology. conclusions: the authors are hopeful that the obtained data will help develop a better device for the percutaneous transcatheter closure of pda.