Right sided aortic arch

Right-sided aortic arch is a type of aortic arch variant characterised by the aortic arch coursing to the right of the trachea. Different configurations can be found based on the supra-aortic branching patterns, with the two most common patterns being the right-sided aortic arch with mirror image branching and the right-sided aortic arch with aberrant left subclavian artery (ALSA).

A right-sided aortic arch is thought to occur in approximately ~0.1% (range 0.05-0.2%) of the population.

Classification

Right-sided arches can be divided into at least three types (please note that the numbering of the types varies from publication to publication and as such the abnormality should be described rather than merely numbered) 1,7,11-13.

  • type I: right-sided aortic arch with mirror image branching
  • type II: right-sided aortic arch with aberrant left subclavian artery
    • common 1, at least accounting for 39.5% of all right sided arches 11
    • associated with Kommerell's diverticulum 11
    • occurs from interruption of the dorsal segment of the left arch between the left common carotid and left subclavian arteries with regression of the right ductus arteriosus in the hypothetical double aortic arch
    • rarely produces symptoms and is usually incidental although can rarely cause oesophageal and/or tracheal compression 10
    • rarely associated with other cardiovascular abnormalities
  • type III: right sided aortic arch with isolation of the left subclavian artery 1,6
Plain radiograph
  • left aortic contour is absent
  • tracheal bowing to the left at the level of the right aortic arch
  • soft tissue indentation on the right side of the distal trachea
  • right sided descending aorta

The right arch is often seen as high riding and projecting as a mass in the right paratracheal region 4.

CT/MRI

Cross-sectional imaging with CT or MRI allows direct visualisation of arch anatomy and with dedicated angiographic techniques (MRA or CTA) excellent demonstration of the lumen can be achieved. 

Thoracic anatomy
Share article

Article information

rID: 22544
Systems: Chest, Vascular
Section: Anatomy
Synonyms or Alternate Spellings:
  • Right aortic arch
  • Right sided aortic arch (RAA)
  • Right sided aortic arch (RSAA)
  • Right-sided aortic arch (RAA)

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 1
    Drag here to reorder.
  • Drag
    Case 2: with aberrant left subclavian artery
    Drag here to reorder.
  • Drag
    Case 3
    Drag here to reorder.
  • Drag
    Case 4
    Drag here to reorder.
  • Drag
    Right Aortic Arch
    Case 5
    Drag here to reorder.
  • Drag
    Case 6
    Drag here to reorder.
  • Drag
    Case 7
    Drag here to reorder.
  • Drag
    Case 8
    Drag here to reorder.
  • Drag
    Case 9
    Drag here to reorder.
  • Drag
    Case 10
    Drag here to reorder.
  • Drag
    Case 11
    Drag here to reorder.
  • Drag
    Case 12
    Drag here to reorder.
  • Drag
    Case 13
    Drag here to reorder.
  • Drag
    Coronal MIP
    Case 14
    Drag here to reorder.
  • Drag
    Frontal radiograph.
    Case 15
    Drag here to reorder.
  • Drag
    Case 16
    Drag here to reorder.
  • Drag
    Case 17
    Drag here to reorder.
  • Drag
    Case 18
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.