kommerell diverticulum

Right-sided

aortic arch with aberrant left subclavian artery. Absent left aortic contour, presence of right aortic knob (red arrow), both hemidiaphragms are flat and low in position.

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A rare

complication of vertebral metastasis surgery. Active extravasation of contrast into the posterior mediastinum and paravertebral region is observed posterior to the right subclavian artery but the originating point of the bleeding vessel is not identified.

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Right-sided

aortic arch with aberrant left subclavian artery. Right aortic arch (white arrow), distal tracheal deviation to the left (yellow arrow).

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Right-sided

aortic arch with aberrant left subclavian artery. The descending aorta (D)continues inferiorly on the right side of the vertebral column.

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Right-sided

aortic arch with aberrant left subclavian artery. Lateral view, slight rotation: 1. left CCA 2. right CCA 3. right subclavian artery 4. left subclavian artery (last branch) 5. Kommerell’s diverticulum 6. right-sided aortic arch 7. descending aorta

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Computed

tomography in the evaluation of vascular rings and slings. Right aortic arch with Kommerell’s diverticulum. a Illustration of a right aortic arch (black arrow) with a prominent Kommerell diverticulum (white arrow) in the proximal descending thoracic aorta (*), compressing the oesophagus (E). b Axial CT scan shows a right aortic arch (arrow) with a large Kommerell diverticulum (arrowhead) compressing the posterior oesophagus. c Coronal MIP image demonstrates a right aortic arch (arrow) and prominent Kommerell diverticulum (arrowhead) in the proximal descending thoracic aorta (*). d Reconstructed 3D volume-rendered image exquisitely demonstrates the right aortic arch (arrow) with a large Kommerell diverticulum (*) giving off the retroesophageal aberrant left subclavian artery (arrowhead). e Coronal CT image shows airway narrowing (arrow) caused by the vascular ring

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Kommerell diverticula occur in some anomalies of the aortic arch system. It usually refers to the bulbous configuration of the origin of an aberrant left subclavian artery in the setting of a right-sided aortic arch. However, it was originally described as a diverticular outpouching at the origin of an aberrant right subclavian artery with a left-sided aortic arch.

Epidemiology

The prevalence of aberrant right and left subclavian arteries is approximately 0.7-2% and 0.04-0.4% of the population respectively . in 20-60% of people with aberrant subclavian arteries are associated with Kommerell’s diverticulum .

Clinical presentation

Kommerell diverticulum may be asymptomatic or cause symptoms of esophageal or tracheal obstruction. Presentation in childhood can often be with airway symptoms whereas dysphagia and chest discomfort can be more common in the adult presentation.

Pathology

It is considered a developmental error with a remnant of the fourth dorsal aortic arch. Recent histological studies have suggested the presence of cystic medial necrosis in the diverticulum wall.

Radiographic features

Plain radiograph

On chest radiographs, a small rounded density may be seen laterally towards the left of the trachea.

Fluoroscopy

On a barium swallow, an impression can be seen from the left side of the esophagus simulating a double aortic arch.

CT/MRI

Typically shows bulbous enlargement of the proximal subclavian artery at its origin from the aortic arch, posterior to the esophagus.

Treatment and prognosis

Given the rarity of this condition, there is no established management guideline. Options include aortic replacement or thoracic endovascular stent-graft replacement (TEVAR), and extra-anatomic bypass of the aberrant subclavian artery . Many consider surgical intervention once the diameter of the diverticulum orifice exceeds 30 mm, and/or the diameter of the descending aorta adjacent to the diverticulum exceeds 50 mm .