Lateral dorsal cutaneous branch of posterior intercostal artery

The lateral dorsal cutaneous branch of the posterior intercostal artery is a terminal cutaneous branch of the dorsal branch of a posterior intercostal artery that supplies the skin of the lateral part of the back, away from the midline.

The posterior intercostal arteries (arising mainly from the thoracic aorta) run within the intercostal spaces. Each gives off a dorsal branch near the vertebral column. The dorsal branch divides into:

• a spinal branch (to the vertebral canal and spinal cord)

• cutaneous branches, including:

  • the medial dorsal cutaneous branch

  • the lateral dorsal cutaneous branch

Territory supplied

• Skin over the lateral posterior thoracic wall

• Region overlying the erector spinae and more lateral back muscles

• Extends toward the posterior axillary line