Figure 1
Chest PA x-ray
Note the enlarged superior mediastinum with a rounded morphology (arrowhead)
An incidental finding: Mediastinal enlargement found to be an anatomic aortic arch variant
SectionCardiovascular
Case TypeClinical Cases
Authors
José Juan Molina Najas
Connected authors
57 years, female
Clinical History
A 57-year-old woman visited the family doctor after finding a lump in her neck. Blood test results were normal. Chest x-ray showed mediastinal abnormalities, so a chest CT scan was ordered preferential to rule out lymphoma.
Imaging Findings
The chest x-ray showed an enlargement of the superior mediastinum with a rounded morphology.
A chest CT scan demonstrated a right-sided aortic arch which presented a protrusion in the origin of the left subclavian artery. This outpouching of the aorta is called Kommerell's diverticulum and is located posterior to the esophagus.
The left and right carotid arteries emerged from the ascending aorta; the right subclavian artery arose from the aortic arch's proximal segment, and the left subclavian artery appeared distally from the retro-esophageal diverticulum. The diverticulum compressed the esophagus at this level.
No cervical, supraclavicular or mediastinal adenopathies were found.
Discussion
The right aortic arch with aberrant left subclavian artery arising from a retro-esophageal diverticulum is the second most common congenital variant of the aortic arch after a double aortic arch [1,2]. Its reported prevalence is 0.04-0.4% [3].
The primitive aorta has a ventral and a dorsal segment connected by six pairs of arches. Archs progressively regress in a caudal direction.
The aortic arch variant of our case derives from the regression of the arch between the left common carotid and subclavian arteries. Kommerell's diverticulum is a remnant of the dorsal left fourth arch [2].
This anatomic variant is commonly asymptomatic, with generally no associated heart disease.
Compression of the esophagus or trachea can occur, resulting in dysphagia or dyspnea [2,3].
The diagnosis is usually casual. It is important to recognise and describe anatomic aortic variants and their relation with mediastinal structures, to avoid complications derived from possible future surgeries [4].
Treatment is generally conservative. Surgery or endovascular stent-graft replacement are reserved for cases when there is severe dysphagia; the diameter of the diverticulum orifice exceeds 3 cm, or the diameter of the descending aorta adjacent to the diverticulum is superior to 5 cm [3].
All patient data have been completely anonymised throughout the entire manuscript and related files.
Differential Diagnosis List
Right aortic arch with aberrant left subclavian artery arising from a Kommerell's diverticulum
Thoracic aorta aneurysm
Double aortic arch
Mediastinal tumors
Final Diagnosis
Right aortic arch with aberrant left subclavian artery arising from a Kommerell's diverticulum
References
[1] Maldonado JA, Henry T, Gutiérrez FR (2010) Congenital thoracic vascular anomalies. Radiologic clinics of North America 48(1):85–115. (PMID: 19995631)
[2] Hanneman K, Newman B, Chan F (2017) Congenital Variants and Anomalies of the Aortic Arch. Radiographics: a review publication of the Radiological Society of North America, Inc 37(1):32–51. (PMID: 27860551)
[3] Tanaka A, Milner R, Ota T (2015) Kommerell's diverticulum in the current era: a comprehensive review. General thoracic and cardiovascular surgery 63(5):245–259. (PMID: 25636900)
[4] Simón-Yarza I, Viteri-Ramírez G, Etxano J, Roblero PS, Ferreira M, Alemañ GB (2011) Arco aórtico derecho, divertículo de Kommerell y arteria subclavia izquierda aberrante [Right aortic arch, Kommerell's diverticulum and aberrant left subclavian artery]. Anales del sistema sanitario de Navarra 34(2):295–300. (PMID: 21904412)
Case information
| URL: | https://www.eurorad.org/case/18123 |
| DOI: | 10.35100/eurorad/case.18123 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 2
Contrast-enhanced chest CT, arterial phase
Axial (left) and coronal-obliqued (right) images evidence the left aberrant subclavian artery arising from retro-esophageal (Kommerell) diverticulum (arrows). The trachea and esophagus are located anteriorly to the aortic arch
Figure 3
Contrast-enhanced chest CT, arterial phase
Anterior (left) and posterior (right) coronal volume-rendered reconstructions show the situation of the supra-aortic vessels. Kommerell’s diverticulum is appreciated (asterisks)
Chest PA x-ray
Note the enlarged superior mediastinum with a rounded morphology (arrowhead)
Department of Radiology, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain, 2022
Department of Radiology, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain, 2022
Contrast-enhanced chest CT, arterial phase
Axial (left) and coronal-obliqued (right) images evidence the left aberrant subclavian artery arising from retro-esophageal (Kommerell) diverticulum (arrows). The trachea and esophagus are located anteriorly to the aortic arch
Department of Radiology, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain, 2022
Department of Radiology, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain, 2022
Contrast-enhanced chest CT, arterial phase
Anterior (left) and posterior (right) coronal volume-rendered reconstructions show the situation of the supra-aortic vessels. Kommerell’s diverticulum is appreciated (asterisks)
Department of Radiology, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain, 2022
Department of Radiology, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain, 2022