aortopulmonary space aortopulmonary space the aortopulmonary space is a small space between the aortic arch and the pulmonary artery. it contains the ligamentum arteriosum, the recurrent laryngeal nerve, lymph nodes, and fatty tissue. the space is bounded anteriorly by the ascending aorta, posteriorly by the descending aorta, medially by the left main bronchus, and laterally by mediastinal pleura. for the congenital heart defect, see aortopulmonary window. on a lateral chest radiograph, the aortopulmonary space is normally seen as the "aortopulmonary window". the presence of radiodensity in this space on radiography may indicate lymphadenopathy. on a posteroanterior chest radiograph like this one, the left margin of the aortopulmonary space is normally seen as the "aortopulmonary angle".