Determining Arch Sidedness

• Marker at 3 o'clock, drop tail to follow the innominate artery as it branches. 
• If right-sided arch then turn to 6 o'clock, rather than 12 o'clock, when in the Supra sternal notch long.

Branches of a Normal Ao Arch

• Innonminate/Brachiocephalic Artery-Right Subclavian Artery and Right Common Carotid Artery
• Left Common Carotid Artery
• Left Subclavian Artery

Cervical Ao Arch

• Normal Variant
• Elongation of the aortic arch into the neck above the clavicle

Right Ao Arch

• Aorta descends on the rt
• Mirror image of left aortic arch
• Left brachiocephalic-left common carotid and left subclavian artery
• Right common carotid
• Right subclavian artery
• In isolation the right aortic arch is not clinically significant
• Need to document in case of future procedures (ie. Surgeries)
• Right arch: highly associated with Tetrology of Fallot

Aberrant Subclavian Artery

• The most common congenital vascular anomaly of the Ao Arch.
• Rare anatomical variant of the origin of the right or left subclavian artery.
• Left aortic arch: aberrant right subclavian artery.
• Right aortic arch: aberrant left subclavian artery. Can create a vascular ring.  

Vascular Ring

• Ring of vessels that surround the trachea and esophagus
• Causes compression of the trachea and esophagus
• May have respiratory distress, stridor (usually newborns in for respiratory issue; almost like high pitched gasping) , trouble swallowing food
• Can occur with a right or double aortic arch…not left arch  

Vascular Ring-Right Ao Arch w/Aberrant Left SCA

• Second most common vascular ring
• Trachea and esophagus is surrounded by the arch, aberrant left subclavian artery and the ligumentus arteriousus coming off of the right subclavian artery
• Treatment: cut the ligamentum arteriosus to relieve compression

Vascular Ring-Double AO Arch

• Most common vascular ring (40%)
• Embryology: lack of regression of the left side of the embryonic double aortic arch
• Persistence of the double arch causes compression of trachea and esophagus
• Echo: needs to determine if the arch is a right or left dominant arch
• Document where all of the branching vessels are located
• Treatment: removal of the smaller aortic arch or sewing the smaller arch into the dominant arch 

Vascular Ring-Pulmonary Sling

• Left pulmonary artery arises from the RPA
• Passes posteriorly between the trachea and esophagus-type of vascular ring 
• Treatment: re-implantation of LPA into MPA