Double Aortic Arch Workup

Updated: Jan 12, 2015
  • Author: Doff B McElhinney, MD; Chief Editor: Stuart Berger, MD  more...
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Workup

Laboratory Studies

In differentiating double aortic arch from upper or lower respiratory infections, a WBC count and respiratory viral studies may be helpful. However, because patients with double aortic arch are predisposed to respiratory infections, the diagnosis of an infection does not exclude the possibility of double aortic arch.

As a result of the possible association between double aortic arch and band 22q11 deletion, practitioners may wish to obtain a karyotype and a fluorescence in situ hybridization (FISH) test for deletions within band 22q11. The diagnosis of band 22q11 deletions allows targeted evaluation and follow-up care for conditions frequently found in patients with this chromosomal anomaly.

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Electrocardiography

No characteristic ECG findings are associated with double aortic arch, and ECG findings are usually normal, except in patients with associated cardiovascular anomalies.

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Procedures

Diagnostic procedures are generally not necessary in the evaluation of patients with a double aortic arch.

Patients with a double aortic arch do not require a histologic tissue examination.

Bronchoscopy

Bronchoscopy may be obtained in the evaluation of a patient with a suspected airway pathologic condition but is not indicated in most patients. Pulsatile compression of the posterior and lateral walls of the trachea can be observed in patients with a double aortic arch, but the specific type of vascular ring cannot always be determined. Other imaging modalities, especially MRI and CT, permit characterization of the severity and location of tracheal obstruction while offering superior definition of vascular anatomy.

In some patients, depending on surgeon preference, bronchoscopy may be performed in the operating room before and after repair of the vascular ring to determine the efficacy of relief of tracheal compression. This is of particular value in young patients in whom persistent tracheomalacia is a concern.

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Chest Radiography

In patients with a double aortic arch, chest radiography may indicate the presence of a vascular ring. In some patients, lateral indentation of the tracheal air column may be revealed by anteroposterior or posteroanterior projection, usually in both the more superior right arch and the more inferior left arch. On lateral chest films, posterior indentation of the trachea by the right arch may be depicted.

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Echocardiography

In most patients, the diagnosis of double aortic arch can be made reliably based on echocardiography; helpful information is obtained with suprasternal, high parasternal, and subcostal imaging. However, because patients with a vascular ring typically present with respiratory symptoms, the diagnosis is usually made based on other imaging modes.

Echocardiography is important in the evaluation of associated cardiovascular anomalies. [6]

Double aortic arch may also be identified on prenatal ultrasonography.

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MRI and CT Scanning

Magnetic resonance imaging (MRI) and computed tomography (CT) scanning are the best single imaging studies for the diagnosis and characterization of vascular rings. MRI and CT scanning provide complete information with regard to the arterial branching pattern, clearly demonstrate the locations and extent of airway and esophageal obstruction, and can be used to delineate cardiac anatomy (see image below). In addition to tomographic images, three-dimensional reconstruction of the aorta and airways can be a useful tool for preoperative planning.

Transverse MRI images in a patient with double aor Transverse MRI images in a patient with double aortic arch. Both arches are patent; the right arch is dominant. Images A-F are arranged in a caudad to cephalad order. (A) Transverse image at the level of the pulmonary valve. The ascending aorta (AAo) and descending aorta (DAo), cephalad to the junction of the left and right arches, can be seen. (B) At the level of the pulmonary artery (PA) bifurcation, the distal confluence of the left and right arches forming the single descending aorta is depicted. (C) The distal portions of the left (L) and right (R) arches can be seen posterior and to the left and right sides of the trachea. Note the anteroposterior compression of the tracheal carina (anterior to and between the arches). (D) Moving cephalad, the dominance of the right arch can be seen. (E) At the level of the proximal/transverse aortic arches, the origin of the left and right arches from the rightward ascending aorta can be seen. (F) The left and right common carotid and subclavian arteries arise from the left and right arches, respectively. The common carotid arteries are the dark round structures anterior to and to either side of the trachea. The subclavian arteries are the dark round structures posterior to and to either side of the trachea.

A study by Chen et al indicated that multislice spiral CT (MSCT) scanning is an effective means of diagnosing double aortic arch and associated complications. In a study of 15 patients with double aortic arch, MSCT scanning identified all 15 cases and also revealed the presence of malformation and tracheobronchial stenosis. The investigators also found that ultrasonography successfully diagnosed only nine of the 15 cases. [7]

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Cardiac Catheterization

This is not usually indicated in patients with double aortic arch. Although angiography was once the criterion standard for the diagnosis of this anomaly, MRI is both less invasive and diagnostically superior. Angiograph findings may be somewhat confusing because of the overlapping projection of the various vascular structures. This problem may be somewhat ameliorated by the use of digital subtraction angiography or countercurrent brachial angiography, which provide sequential information that can help clarify the aortic branching pattern.

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Barium Esophagography

Frequently, the diagnosis of a vascular ring is made initially with barium esophagography. In patients with a double aortic arch, bilateral indentation of the esophagus is observed on the anteroposterior view, with the right-sided indentation superior to the left, and posterior indentation is observed on the lateral view.

Although this test is not necessary to make the diagnosis of double arch, it often is obtained in the preliminary evaluation of patients with symptoms of an upper airway and/or an esophageal pathologic condition. If a ring is strongly suspected on the basis of chest radiography or echocardiography findings, barium esophagography is not indicated. Rather, if additional imaging is desired, a more thorough diagnostic study, such as MRI, should be performed.

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