The lateral thoracic artery (long thoracic artery) is a branch of the axillary artery.

It supplies several structures in the axilla and anterior thoracic wall.

Course

The lateral thoracic artery originates from the 2nd part of the axillary artery (posterior to pectoralis minor).

It courses vertically downward along the lateral border of the pectoralis minor muscle. Along its course, it provides several small branches that supply various structures within the axilla and anterior thoracic wall.

It usually terminates at the level of the fifth intercostal space and forms an anastomosis with the internal thoracic artery.

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Fig 1 – Anatomical course of the lateral thoracic artery

Supply

The lateral thoracic artery supplies the following structures:

• Axillary lymph nodes
• Breasts
• Skin of lateral thoracic wall
• Serratus anterior muscle
• Pectoralis major muscle
• Pectoralis minor muscle
• Subscapularis muscle