Chapter30 Aorta

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Section V: Cardiac Radiology

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Figure 30.15.  Double Aortic Arch. PA chest radiograph in an adult ( A ) with mild dysphagia demonstrates two bilateral indentations on the lower trachea (*), a slightly larger and more superior right indentation ( red arrow ) and slightly smaller and more inferior left indentation ( white arrow ). Coronal CT image ( B ) shows that the indentations represent a larger and more superior right aortic arch ( red arrow ) and smaller and more inferior left aortic arch ( white arrow ). Axial MIP image ( C ) shows the double aortic arch. The right arch is larger than the left arch, which is common.

The left arch is typically hypoplastic and located inferior to the dominant right arch (Fig. 30.15), with a left-sided descend- ing thoracic aorta and ductus arteriosus. Since the right and left arches encircle the trachea and esophagus, patients present in childhood with findings of airway compromise, includ- ing wheezing and stridor (Fig. 30.16). Double aortic arch is uncommonly associated with congenital heart disease. Cervical Aortic Arch Cervical aortic arch is extremely rare, with case reports describ- ing a high location of the aortic arch above the level of the clav- icle (Fig. 30.17). It is most often associated with a right arch, although a left cervical arch can occur. While often presenting

as an asymptomatic pulsatile mass in the neck or supraclavicu- lar region, it can be associated with other aortic abnormalities, aneurysm formation, and congenital heart disease.

Interrupted Aortic Arch Interrupted aortic arch occurs in 2 of every 100,000 births, characterized by discontinuity of the aortic arch in which there is complete absence or a fibrous remnant of the inter- rupted segment. There are three main types of interrupted aortic arch (A, B, and C) depending on location of inter- ruption. Type A interruption occurs distal to the left subcla- vian takeoff at the isthmus, type B between the left common carotid and subclavian origins, and type C between the right

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Figure 30.16.  Double Aortic Arch. Axial MIP image in a 1-month-old baby with severe stridor and vomiting ( A ) shows a double aortic arch creating a vascular ring and causing compression of the trachea ( black arrow ). Additionally, lateral view from an esophagram ( B ) shows marked compression of the posterior wall of the esophagus ( black arrow ).