Radiology Quiz Case 1—Diagnosis

The normal anatomy of the central mediastinal great artery system derives from several complex steps of embryonic differentiation, subsequent involutions, and remaining patencies of primary vascular arches.¹ Abnormal embryological differentiation of the aortic arch and central pulmonary arterial system may lead to complex pathologic relationships between these vessels and the tracheobronchial tree. Because of the considerable topographic variability of their origin and course in the mediastinum, some of these vascular malpositions can cause significant compression of the trachea, mainstem bronchi, or esophagus.² These malformations are rare, accounting for 1.0% to 1.6% of all congenital cardiac anomalies.² The disarranged patterns of the great arteries all share a common form of a complete ring or a sling with subsequent tracheal compression.² Approximately 20% of children with symptomatic vascular rings have other associated congenital heart anomalies.³ The anomalies that most often cause airway compression are a double aortic arch or a right aortic arch with an aberrant left subclavian artery and a left ligamentum arteriosum.⁴