It also helps to exclude other causes of airway obstruction, to confirm and to grade the severity of airway compression. īronchoscopy usually occurs pre-operatively to evaluate airway anatomy. 30 to 45 minutes required for a sedated MRI), the fact that CT scans are relatively insensitive to motion and metal and also the reconfiguration of the CT scan as a three-dimensional image, CT is largely preferred over MRI for the diagnosis of DAA. So due to the increasing speed of CT scans (10 to 20 seconds vs. It points the exact locations and extent of airway and esophageal obstructions, and can provide a comprehensive picture of arterial branching patterns. Using this technique, the exact anatomy of the aortic arch malformation and its relationship with adjacent structures can be precisely defined, which can assist the cardiovascular surgeon in planning surgical management. Computed tomography angiography with three-dimensional reconstruction is an excellent non-invasive imaging technique that is used to diagnose and characterize vascular rings. However, advanced imaging using computed tomography (CT) or magnetic resonance imaging (MRI) has become the diagnostic procedure of choice. It shows esophagus left- and right-sided indentations from the vascular compression. Esophagography or barium swallow used to be the gold standard for diagnosis. Chest X-ray can reveal loss of aortic knob, lateral/posterior indentation of the trachea. Electrocardiographic studies are normal unless intra-cardiac structural anomalies are co-existent. In addition, it can identify other intra-cardiac anomalies that may also be present. It may reliably image the aortic arch and its branches. Imaging remains the mainstay of investigationĮchocardiography is a readily available non-invasive technique that has proven useful in investigation of the heart. Sometimes it can include evidence of poor growth and feed intolerance, non-positional stridor, respiratory distress, and features of a lower respiratory infection such as bronchial breath sounds and crackle. Physical examination may often be entirely normal. Life-threatening episodes of reflex apnea with cyanosis have being described. In addition to airway symptoms, and related to esophageal compression, patients may experience swallowing difficulties, which manifests as vomiting and feeding intolerance. ĭue to the anatomic nature of the lesion, DAA may manifest with symptoms of stridor, dyspnea, cough, and recurrent respiratory infections. Often, patients are identified as an incidental finding during routine imaging for other indications, and in some studies some patients are diagnosed after foreign body ingestion, and in an adult with aortic dissection. Children with DAA tend to present earlier than those with the other vascular ring pathology. In accordance with its anatomic characteristics, DAA has been divided into three types : (1) large right posterior arch and small left anterior arch (right dominant aortic arch), accounting for 75% (2) small right rear arch and large left front arch (left dominant aortic arch), accounting for approximately 20% (3) and equal diameter DAA (balanced type aortic arch), accounting for 5%.Ĭlinical presentation depends largely on the existence of hemodynamic instability. The aortic arches give rise to the ipsilateral subclavian and common carotid arteries ( Figure 3), and the innominate artery is absent. The formation of a DAA originates from a failed regression of the right-sided arch with the persistence of the left-sided arch. In week five of gestation, the right-sided arch regresses and the left-sided arch remains, leaving a normal left-sided aortic arch. The third branch forms the common carotid arteries and a small portion of the internal carotid arteries, and the bilateral aortic arches emanate from the fourth pair of arches. In early weeks, the first two arches regress, leaving the maxillary, hyoid, and stapedial arteries. Aortic arch development is a complex process that occurs between weeks two and seven of gestational life. Six pairs of arches appear and disappear at different times, leaving remnants that form important vessels.

Aortic arch ct