Lateral costal branch of internal thoracic artery

The lateral costal branch of the internal thoracic artery (lateral costal artery (LCA)) is a supernumerary branch of the internal thoracic artery (ITA) that occurs in 15-30% of individuals, coursing laterally along the thoracic wall and anastomosing with the intercostal arteries.

The LCA typically arises from the proximal ITA; in one reported case, it originated 2.5 cm below the subclavian artery, measured approximately 2 mm in caliber, and coursed as far as the 4th intercostal space for a distance of 13 cm. The median vessel length is approximately 2 intercostal spaces, though 74% of cases extend beyond the 2nd intercostal space.