Nerve supply of the breast with special reference to the nipple and areola: Sir Astley Cooper revisited.

Cooper in 1840 described mammary branches from the 2nd-6th intercostal nerves, and noticed that the nipple was supplied by branches which lay close to the surface of the gland. Eckhard (1850) divided the mammary branches into superficial branches to the skin and nipple, and deep branches to the glandular tissue and nipple, but many later authors ignored those findings. After the second World War, cosmetic surgery of the breast made further research critical, as surgeons strove to design operations which would retain its shape and preserve postoperative sensation. Craig and Sykes (1970) described mainly anterior branches from the 3rd, 4th and 5th intercostal nerves passing through the glandular tissue of the breast and along the line of the ducts to the nipple, while Farina et al. (1980) concluded that the nipple was supplied solely by superficial lateral branches of the 4th nerve. Using improvements in dissecting technique learned from microsurgery, Sarhadi et al. (1996) found that the nipple was innervated by the lateral cutaneous branch of the 4th intercostal nerve, by two branches, one passing superficial to the gland, and the other through the retromammary space, and by variable lateral and medial additional branches from the 2nd-5th nerves. These branches came to lie superficially and formed a subdermal plexus under the areola. This account is uncannily close to Cooper's original description; it is a reassuring, if sobering, conclusion that his early account remains one of the most reliable.