Breast Arterial Supply

Expansion

• Internal thoracic artery - perforating branches through the upper intercostal spaces, supplying the medial breast; the largest contribution
• Lateral thoracic artery - from the axillary artery, supplying the lateral breast
• Thoracoacromial artery - pectoral branch
• Posterior intercostal arteries - lateral mammary branches to the deep breast

Venous drainage follows the arteries into the internal thoracic, axillary and intercostal veins. The intercostal route connects with the vertebral venous plexus of Batson, which is one explanation for breast carcinoma metastasising to the spine without first involving the lungs.