Three-dimensional/four-dimensional spatiotemporal image correlation morphology of the ductus arteriosus in fetuses with pulmonary atresia undergoing neonatal ductal stenting.

Background: The value of prenatal identification of morphology of ductus arteriosus in fetuses with congenital heart defects (CHD) with pulmonary atresia and duct-dependent pulmonary circulation (DDPC) in planning neonatal ductal stenting procedure is untested. The aim of the study is to analyze the utility of three-dimensional/four-dimensional (3D/4D) spatiotemporal image correlation (STIC) fetal echocardiography in delineating the morphology of ductus arteriosus in fetuses with DDPC undergoing neonatal ductal stenting.

Methods: In this retrospective study (2017-22), prenatal imaging of pulmonary artery (PA) anatomy, aortic arch sidedness, and morphology of ductus arteriosus (ductal origin was classified as vertical/horizontal and ductal course as tortuous/straight) was done using 3D/4D STIC imaging and volume datasets. Prenatal findings were correlated with angiographic findings during stenting and the degree of agreement was calculated.

Results: We included 27 fetuses with a prenatal diagnosis of CHD with DDPC who underwent neonatal ductal stenting. The accuracy of prenatal assessment of PA anatomy, branch PA stenosis, and arch sidedness was 100%, 92.6%, and 88.9%, respectively. The accuracy of prenatal assessment of ductal origin and course, compared with angiography, was 85.2% and 88.9%, respectively. Prenatal imaging had a diagnostic accuracy of 100% for vertical straight and horizontal tortuous ducts, 84.6% for vertical tortuous, and 67% for horizontal straight ducts. Duct stenting was successful in 25 (92.6%) babies; two died after the procedure from stent occlusion.

Conclusion: Fetal echocardiography using 3D/4D STIC imaging enables accurate delineation of the morphology of ductus arteriosus in fetuses with DDPC, thereby aiding parental counseling and planning neonatal ductal stenting.