Sternal branches of internal thoracic artery

The sternal branches of the internal thoracic artery are small arterial branches that arise from the internal thoracic artery (also known as the internal mammary artery) as it descends along the posterior surface of the anterior chest wall. These branches perforate the intercostal spaces to supply the sternum, including its periosteum, and the surrounding tissues.

The internal thoracic artery originates from the first part of the subclavian artery and descends approximately 1 cm lateral to the sternal border, posterior to the costal cartilages and the internal intercostal muscles. Along its course, it gives off several sets of branches:

• Sternal branches: These are small, perforating vessels that course medially to supply the sternum itself including the body, manubrium, and their periosteum. They anastomose with contralateral sternal branches, contributing to the blood supply of the sternum and playing a role in sternal healing after median sternotomy.

• Other branches of the internal thoracic artery include the pericardiacophrenic artery, anterior intercostal arteries, perforating branches, and its terminal divisions the musculophrenic and superior epigastric arteries.