A double aortic arch is a form of vascular ring that typically presents with airway compromise or dysphagia. Embryologically, the arch results from the persistence of the fourth aortic arch. Although both arches typically remain patent, atresia of a portion of one arch can occur. Four subtypes of double aortic arches with left atresia are described (Fig 1).1
We report two patients presenting to our institution with near identical double aortic arches, left arch atresia subtype 2. Subtype 2 occurs when the segment between the ligamentum arteriosum and left subclavian artery becomes atretic. Patient 1 was a 5-year-old male who presented with recurrent upper respiratory infections, occasional wheezing, and mild dysphagia. Patient 2 was a 1-year-old female with an intermittent raspy voice through her first year of life and frequent upper respiratory infections. Prior imaging raised concerns for a vascular ring. Cardiac magnetic resonance imaging in both patients revealed a double aortic arch with distal left arch atresia (white arrow) and a persistent diverticulum of Kommerell (Fig 2). The findings are consistent with subtype 2 double aortic arch atresia (Audio Video Interleave).
The presence of the diverticulum of Kommerell helps distinguish between subtypes 1 and 2. If the atretic arch alone is divided, a vascular ring will remain because of the persistent ligament.
Figure 3depicts the division of the atretic arch and ligamentum performed through a left thoracotomy.