--- title: "Double Aortic Arch" docid: "0b68477f-f05a-4e4c-a1a8-02fe29c292db" authors: - key: "ee6ece9d-ad74-458c-a8df-11628ae7f879" value: "Arzu Canan, MD" - key: "10bb95ac-a27a-4ebe-833b-e59fea07734b" value: "Santiago Mart\u00ednez-Jim\u00e9nez, MD, FACR" breadcrumbs: - name: "Cardiac" slug: "cardiac" treeNodeId: "fa90100b-619c-430e-8074-b5b9789bab39" - name: "Diagnosis" slug: "diagnosis" treeNodeId: "5c92cf4f-e9d5-4059-9c13-22255c51c121" - name: "Aorta" slug: "aorta" treeNodeId: "4d206a6b-1a82-467c-9199-0df25ab749d7" - name: "Double Aortic Arch" slug: "double-aortic-arch" treeNodeId: null category: "Cardiac" documentVersionId: "3dc4caa1-09b8-4045-b792-da5ec170e56b" imageCount: 19 lastUpdated: "03/09/25" pageDescription: "Double Aortic Arch" pageKeywords: "Cardiac, Diagnosis, Aorta, Double Aortic Arch" pageTitle: "Double Aortic Arch | STATdx" enhancedTitle: "Double Aortic Arch" type: "DX" references: true breadcrumbs: - "Cardiac" - "Diagnosis" - "Aorta" - "Double Aortic Arch" --- # KEY FACTS - ## Terminology - Double aortic arch (DAA) - Persistent right and left aortic arches, each one giving rise to separate ipsilateral subclavian and carotid arteries - ## Imaging - Chest radiography - Frontal projection: Bilateral paratracheal opacities, bilateral tracheal indentations - Lateral projection: Posterior tracheal indentation - CTA - Right aortic arch - Larger and higher in most patients (right dominant) - Left aortic arch - Often smaller than right aortic arch - 4-artery sign: Symmetric take-off of 4 aortic branches on axial image at thoracic inlet (2 ventral carotids and 2 dorsal subclavians) - 1 descending aorta, usually contralateral to dominant arch (i.e., left) - Airway CT - Tracheomalacia: Tracheal collapse adjacent to vascular ring during expiration - Bronchomalacia: Left main bronchus collapse adjacent to midline descending aorta during expiration - ## Clinical Issues - Most common symptomatic vascular ring - Typically manifests in neonates - Children - Dyspnea, often during feeding - Stridor and wheezing (exacerbated by crying) - Tachypnea, apnea - Adults - May be asymptomatic - Treatment: Surgical division of smaller or atretic aortic arch and ligamentum arteriosus # TERMINOLOGY - ## Abbreviations - Double aortic arch (DAA) - ## Definitions - Persistent right and left aortic arches, each one giving rise to separate ipsilateral subclavian and carotid arteries - Variants - Both arches patent and functioning - Right arch patent, left arch atretic - Difficult to differentiate from right aortic arch mirror image branching # IMAGING - ## General Features - ### Best diagnostic clue - Chest radiography: Bilateral paratracheal opacities with concentric midtracheal narrowing - ## Radiographic Findings - ### Radiography - Frontal projection - Bilateral paratracheal opacities - Bilateral tracheal indentations - Lateral - Posterior tracheal indentation - ## Fluoroscopic Findings - ### Esophagram - Frontal projection: S-shaped, bilateral indentations on contrast-filled esophagus, right higher and larger than left - Lateral view: Large posterior indentation, often oblique - ## CT Findings - ### CTA - Right aortic arch - Larger in most patients (right dominant) - More cephalad than left - Courses behind esophagus - Left aortic arch - Often smaller than right aortic arch - Rarely same size (codominant) or larger (left dominant) - Left aortic arch atresia can be confused with right aortic arch - Inferior tethering of left subclavian artery - ± aortic diverticulum - Posterior course of proximal head and neck vessels - Focal narrowing of airway - **4-artery sign**: Symmetric take-off of 4 aortic branches on axial image at thoracic inlet (2 ventral carotids and 2 dorsal subclavians) - 1 descending aorta, usually contralateral to dominant arch (i.e., left) - Airway CT - Inspiration and expiration CT may help differentiate tracheomalacia from tracheal stenosis - Tracheomalacia: Tracheal collapse adjacent to vascular ring during expiration - Bronchomalacia: Left main bronchus collapse adjacent to midline descending aorta during expiration - ## MR Findings - As accurate as CT in assessing vascular anatomy and tracheal stenosis - Of value in young individuals due to lack of ionizing radiation - Same findings as CT - ## Echocardiographic Findings - ### Echocardiogram - Suprasternal notch view is most helpful, showing 2 separate aortic arches, each giving rise to separate carotid and subclavian arteries - Poor assessment of airway compression - ## Imaging Recommendations - ### Best imaging tool - MR and CT are equally accurate in assessing vascular and tracheal anatomy - ### Protocol advice - Multiplanar reformations are helpful in delineating arch anatomy and tracheal abnormalities # DIFFERENTIAL DIAGNOSIS - ## Right Aortic Arch With Aberrant Left Subclavian Artery and Kommerell Diverticulum - Kommerell diverticulum may mimic left aortic arch on frontal chest radiograph - Tracheal indentation on lateral chest radiograph - Differentiation usually requires cross-sectional imaging - ## Right Aortic Arch With Mirror Image Branching and Aortic Diverticulum - Lack of inferior tethering of left subclavian artery - Aortic diverticulum is more common in DAA with atretic left aortic arch - DAA with atretic left aortic arch and right aortic arch with mirror image branching and aortic diverticulum are part of spectrum of vascular rings and have similar clinical implications - ## Left Pulmonary Artery Sling - Anterior esophageal and posterior tracheal indentations - May be associated with tracheomalacia - [Innominate Artery Compression Syndrome](/document/innominate-artery-compression-synd-/bc9f2319-6c01-4218-b75b-3481b2461738) - Anterior tracheal indentation without esophageal compression - ## Mediastinal Mass - Mediastinal masses can cause tracheal compression # PATHOLOGY - ## General Features - ### Etiology - Persistence of right and left 4th aortic arches - ### Associated abnormalities - Often not associated with congenital heart disease - 20% associated with congenital heart disease - Tetralogy of Fallot (most common) - Ventricular septal defect - Aortic coarctation - Patent ductus arteriosus - Transposition of great arteries - Truncus arteriosus - Tracheobronchomalacia - May cause persistent airways symptoms after surgery - ## Gross Pathologic & Surgical Features - Tight vascular ring with tracheal and esophageal compression - Dominance: Right (~ 70%) > left (~ 20%) > codominant (~ 5%) - Smaller left arch may be partially atretic # CLINICAL ISSUES - ## Presentation - ### Most common signs/symptoms - Children - Dyspnea, often during feeding - Stridor and wheezing (exacerbated by crying) - Tachypnea, apnea - Recurrent respiratory infections - Dysphagia - Adults - May be asymptomatic - Esophageal obstruction (i.e., dysphagia) - ## Demographics - Most common symptomatic vascular ring - Typically manifests in neonates - Affects 0.05-0.3% of general population - ## Treatment - Surgical division of smaller or atretic aortic arch and ligamentum arteriosus af9c9eb2-551e-4968-a9d6-7738cac6154b ## References # Selected References 1. [Gikandi A et al: Outcomes of patients undergoing surgery for complete vascular rings. J Am Coll Cardiol. 84(14):1279-92, 2024](http://www.ncbi.nlm.nih.gov/pubmed/?term=39322321%5Bpmid%5D) 1. [Li S et al: Congenital abnormalities of the aortic arch: revisiting the 1964 Stewart classification. Cardiovasc Pathol. 39:38-50, 2018](http://www.ncbi.nlm.nih.gov/pubmed/?term=30623879%5Bpmid%5D) 1. [Hanneman K et al: Congenital variants and anomalies of the aortic arch. Radiographics. 37(1):32-51, 2017](http://www.ncbi.nlm.nih.gov/pubmed/?term=27860551%5Bpmid%5D) 1. [Newman B et al: Persistent fifth arch anomalies - broadening the spectrum to include a variation of double aortic arch vascular ring. Pediatr Radiol. 46(13):1866-72, 2016](http://www.ncbi.nlm.nih.gov/pubmed/?term=27669708%5Bpmid%5D) 1. [Ramos-Duran L et al: Developmental aortic arch anomalies in infants and children assessed with CT angiography. AJR Am J Roentgenol. 198(5):W466-74, 2012](http://www.ncbi.nlm.nih.gov/pubmed/?term=22528928%5Bpmid%5D) 1. [Dillman JR et al: Common and uncommon vascular rings and slings: a multi-modality review. Pediatr Radiol. 41(11):1440-54; quiz 1489-90, 2011](http://www.ncbi.nlm.nih.gov/pubmed/?term=21594540%5Bpmid%5D) 1. [Kanne JP et al: Right aortic arch and its variants. J Cardiovasc Comput Tomogr. 4(5):293-300, 2010](http://www.ncbi.nlm.nih.gov/pubmed/?term=20829147%5Bpmid%5D) 1. [Kellenberger CJ: Aortic arch malformations. Pediatr Radiol. 40(6):876-84, 2010](http://www.ncbi.nlm.nih.gov/pubmed/?term=20354848%5Bpmid%5D) 1. [Holmes KW et al: Magnetic resonance imaging of a distorted left subclavian artery course: an important clue to an unusual type of double aortic arch. Pediatr Cardiol. 27(3):316-20, 2006](http://www.ncbi.nlm.nih.gov/pubmed/?term=16565909%5Bpmid%5D) 1. [Chan MS et al: Angiography and dynamic airway evaluation with MDCT in the diagnosis of double aortic arch associated with tracheomalacia. AJR Am J Roentgenol. 185(5):1248-51, 2005](http://www.ncbi.nlm.nih.gov/pubmed/?term=16247144%5Bpmid%5D) ## Images ### Selected Images ![Composite axial CTA at contiguous levels in a patient with a double aortic arch (DAA) shows symmetric take-off of 4 aortic branches at thoracic inlet (i.e., 2 carotids and 2 subclavian arteries), the so-called 4-artery sign. This sign has been described in the setting of DAA. Note the right aortic arch (RAA) .](images/app.statdx.com_image_thumbnail_056bc355-630b-41fd-9627-13707c6b1cb7_annotated_true_size_900_quality_90_4a8ad8012ff039f3da2f357def2ebf31539879ae.jpg) *Composite axial CTA at contiguous levels in a patient with a double aortic arch (DAA) shows symmetric take-off of 4 aortic branches at thoracic inlet (i.e., 2 carotids and 2 subclavian arteries), the so-called 4-artery sign. This sign has been described in the setting of DAA. Note the right aortic arch (RAA) .* ![Composite axial CTA at contiguous levels in a patient with a double aortic arch (DAA) shows symmetric take-off of 4 aortic branches at thoracic inlet (i.e., 2 carotids and 2 subclavian arteries), the so-called 4-artery sign. This sign has been described in the setting of DAA. Note the right aortic arch (RAA) .](images/app.statdx.com_image_thumbnail_056bc355-630b-41fd-9627-13707c6b1cb7_size_174_quality_85_b8b3f5baa93dda62d3cca61179e8e131f3c8b76a.jpg) *Composite axial CTA at contiguous levels in a patient with a double aortic arch (DAA) shows symmetric take-off of 4 aortic branches at thoracic inlet (i.e., 2 carotids and 2 subclavian arteries), the so-called 4-artery sign. This sign has been described in the setting of DAA. Note the right aortic arch (RAA) .* ![Composite axial CTA in the same patient shows the larger RAA and smaller left aortic arch . Note the left descending thoracic aorta , which is typically contralateral to the dominant arch.](images/app.statdx.com_image_thumbnail_d6625d13-5661-4eaa-909b-c54700a844dc_annotated_true_size_900_quality_90_fcc456b67e7685a96d148062cb0e36e493adf02d.jpg) *Composite axial CTA in the same patient shows the larger RAA and smaller left aortic arch . Note the left descending thoracic aorta , which is typically contralateral to the dominant arch.* ![Coronal CTA in the same patient shows a cephalad, larger RAA and a more caudal, smaller left aortic arch . Note the mild tracheal impression of the RAA. A larger RAA is the most common variant seen in DAA.](images/app.statdx.com_image_thumbnail_28b91c1b-5929-4fe2-95c9-4ed4431c6f94_annotated_true_size_900_quality_90_e188af928beccaa9e9df2773527693007a11093a.jpg) *Coronal CTA in the same patient shows a cephalad, larger RAA and a more caudal, smaller left aortic arch . Note the mild tracheal impression of the RAA. A larger RAA is the most common variant seen in DAA.* ![Sagittal CTA in the same patient shows the distal RAA causing a posterior indentation of the trachea. Also note the ascending aorta (with slab artifact) and the proximal left aortic arch .](images/app.statdx.com_image_thumbnail_1175a3f3-3a9e-4ffa-ac1a-b05413b5eb40_annotated_true_size_900_quality_90_86d8f9bc2b76ed770570e909b0ac8bc662bd0063.jpg) *Sagittal CTA in the same patient shows the distal RAA causing a posterior indentation of the trachea. Also note the ascending aorta (with slab artifact) and the proximal left aortic arch .* ![Frontal radiograph in the same patient shows mild concentric narrowing of the midtrachea with more prominent right paratracheal nodular opacity.](images/app.statdx.com_image_thumbnail_bbe4fecd-7fd2-43a9-8472-51766eacb059_annotated_true_size_900_quality_90_04dc3b19a8629d6e02b16b5939691ee229dc864b.jpg) *Frontal radiograph in the same patient shows mild concentric narrowing of the midtrachea with more prominent right paratracheal nodular opacity.* ![Lateral radiograph in the same patient shows the posterior tracheal indentation from retrotracheal course of the RAA, a classic finding in DAA. This narrowing is often related to the distal portion of the RAA, as it courses posterior to the esophagus to join the RAA.](images/app.statdx.com_image_thumbnail_b334f1a2-e1b9-4fd6-9efc-ddea184b18ab_annotated_true_size_900_quality_90_5a2f37edec4d5c5569d5aa2ca50afa1c18b2b9be.jpg) *Lateral radiograph in the same patient shows the posterior tracheal indentation from retrotracheal course of the RAA, a classic finding in DAA. This narrowing is often related to the distal portion of the RAA, as it courses posterior to the esophagus to join the RAA.* ![Sagittal 3D reformation of chest CTA shows a patent RAA and smaller left aortic arch . There are 4 major symmetrical branches (2 ventral carotids and 2 dorsal subclavian arteries), each set arising form each aortic arch. This is known as the 4-artery sign. The trachea and esophagus (not shown) are completely surrounded by the vascular ring.](images/app.statdx.com_image_thumbnail_13267992-a377-4605-b624-a9c44c739b3d_annotated_true_size_900_quality_90_b86802c0e99268d35c29d57e1375e53a9807452e.jpg) *Sagittal 3D reformation of chest CTA shows a patent RAA and smaller left aortic arch . There are 4 major symmetrical branches (2 ventral carotids and 2 dorsal subclavian arteries), each set arising form each aortic arch. This is known as the 4-artery sign. The trachea and esophagus (not shown) are completely surrounded by the vascular ring.* ![Graphic shows a DAA with a complete vascular ring encircling and compressing the trachea and esophagus.](images/app.statdx.com_image_thumbnail_f59dfa0e-f5df-4b0f-8cf1-646bff997e13_annotated_true_size_900_quality_90_d711100d2830bc5ef0c6afe92c9e2bad14262831.jpg) *Graphic shows a DAA with a complete vascular ring encircling and compressing the trachea and esophagus.* ![Esophagram in a neonate with stridor shows right and smaller left indentations of the esophagus on frontal view due to a DAA. There is posterior indentation in the lateral view related to the RAA.](images/app.statdx.com_image_thumbnail_f7c5029c-3e36-4a53-9145-64350442f227_annotated_true_size_900_quality_90_328fa3582b77aae674a6b8e24fbe679b2000c8bd.jpg) *Esophagram in a neonate with stridor shows right and smaller left indentations of the esophagus on frontal view due to a DAA. There is posterior indentation in the lateral view related to the RAA.* ![Frontal 3D reformation from a chest CT in an asymptomatic patient with a DAA shows higher and larger right vs. left tracheal indentations on the AP reformation. Note posterior indentation related to the RAA in the lateral reformation.](images/app.statdx.com_image_thumbnail_8673a038-b499-4a88-80d2-6cba9e2018eb_annotated_true_size_900_quality_90_51d9e8302b8d7adcc678c63e518517b7c2dd9f64.jpg) *Frontal 3D reformation from a chest CT in an asymptomatic patient with a DAA shows higher and larger right vs. left tracheal indentations on the AP reformation. Note posterior indentation related to the RAA in the lateral reformation.* ![Lateral chest radiograph in a patient with a DAA shows abnormal posterior tracheal indentation . This can also be seen in the setting of other vascular rings, such as those with diverticulum of Kommerell or pulmonary artery sling.](images/app.statdx.com_image_thumbnail_f92ed5c6-4397-4aeb-9482-8674ab5fd873_annotated_true_size_900_quality_90_8ddbad3fb4322f740df4cf5f7bfaea12d315556b.jpg) *Lateral chest radiograph in a patient with a DAA shows abnormal posterior tracheal indentation . This can also be seen in the setting of other vascular rings, such as those with diverticulum of Kommerell or pulmonary artery sling.* ![Composite axial CTA at contiguous levels shows the RAA and left aortic arch similar in size. Note, however, the lack of the 4-artery sign (i.e., lack of symmetry of the 4 head/neck vessels at the thoracic inlet ). There is a left descending thoracic aorta .](images/app.statdx.com_image_thumbnail_9df559d5-3e22-4a42-af0c-6a651e73fb64_annotated_true_size_900_quality_90_2e8b6f3f75e35c582651e19e190426237ad1f195.jpg) *Composite axial CTA at contiguous levels shows the RAA and left aortic arch similar in size. Note, however, the lack of the 4-artery sign (i.e., lack of symmetry of the 4 head/neck vessels at the thoracic inlet ). There is a left descending thoracic aorta .* ![Frontal chest radiograph in a patient with a DAA with an atretic left arch shows right paratracheal opacity related to the RAA with marked tracheal indentation . The same imaging finding can also be seen in an isolated RAA.](images/app.statdx.com_image_thumbnail_a646ed03-fa6c-490c-9f4a-dd130b060949_annotated_true_size_900_quality_90_8d5487382c80fda52d3613a10f7be33e6fdfa551.jpg) *Frontal chest radiograph in a patient with a DAA with an atretic left arch shows right paratracheal opacity related to the RAA with marked tracheal indentation . The same imaging finding can also be seen in an isolated RAA.* ![Composite axial CTA at contiguous levels in the same patient shows symmetric take-off of 4 aortic branches at the thoracic inlet (i.e., 4-artery sign). Note the presence of a large RAA , which is mildly deviating the trachea to the left.](a1a9d5fe-921b-45d4-b0f4-9b8bd0247413) *Composite axial CTA at contiguous levels in the same patient shows symmetric take-off of 4 aortic branches at the thoracic inlet (i.e., 4-artery sign). Note the presence of a large RAA , which is mildly deviating the trachea to the left.* ![Composite axial CTA at contiguous levels in the same patient shows an atretic left aortic arch with a posteriorly tethered left subclavian artery . The later is helpful to differentiate from an RAA with mirror image branching in which the take-off of the left subclavian artery tends to be more anterior.](9a5931aa-0995-4dc5-bbdc-86e458db3405) *Composite axial CTA at contiguous levels in the same patient shows an atretic left aortic arch with a posteriorly tethered left subclavian artery . The later is helpful to differentiate from an RAA with mirror image branching in which the take-off of the left subclavian artery tends to be more anterior.* ![Sagittal oblique SSD CTA in the same patient shows the posterior tethering of the left subclavian artery and the atretic left aortic arch , resulting in a vascular ring.](9485c0d0-62fe-4473-9ee1-bc5c89351396) *Sagittal oblique SSD CTA in the same patient shows the posterior tethering of the left subclavian artery and the atretic left aortic arch , resulting in a vascular ring.* ### Additional Images ![Axial chest CTA in an asymptomatic adult patient with a DAA with areas of partially atretic left aortic arch (cephalad to caudad progression) demonstrates a RAA and a left aortic arch .](9ea814dd-fd87-4b88-8fa9-062792a51014) *Axial chest CTA in an asymptomatic adult patient with a DAA with areas of partially atretic left aortic arch (cephalad to caudad progression) demonstrates a RAA and a left aortic arch .* ![Axial chest CTA in the same patient shows that the RAA and left aortic arch have joined into 1 descending thoracic aorta . The trachea remains slightly narrowed.](89ce61a7-77a7-4aac-b2d6-6d023455daf9) *Axial chest CTA in the same patient shows that the RAA and left aortic arch have joined into 1 descending thoracic aorta . The trachea remains slightly narrowed.* ![Axial chest CTA more inferiorly shows a common left descending thoracic aorta . The trachea now resumes a normal diameter.](821f397b-209a-4b7a-9fcc-21e71b8c4384) *Axial chest CTA more inferiorly shows a common left descending thoracic aorta . The trachea now resumes a normal diameter.*