Although preservation of the sensitivity of the nipple and areola is an important goal in breast surgery, only scant and contradictory information about the course and distribution of the supplying nerves is found in the literature. The existing controversy might be due to the difficulty in dissecting the thin nerves and to frequent anatomic variations that bias the results if only a small number of cadavers are dissected. We dissected 28 female cadavers and found that the nipple and areola were always innervated by the lateral and anterior cutaneous branches of the 3rd, 4th, and 5th intercostal nerves. The most constant innervation pattern was by the 4th lateral cutaneous branch (79 percent) and by the 3rd and 4th anterior cutaneous branches (57 percent). The anterior cutaneous branches took a superficial course within the subcutaneous tissue and terminated at the medial areolar border in all dissected breasts. The lateral cutaneous branches took a deep course within the pectoral fascia and reached the nipple from its posterior surface in 93 percent of the dissected breasts. In 7 percent of the dissected breasts, the lateral cutaneous branches took a superficial course within the subcutaneous fat and reached the nipple from the lateral side. These findings suggest that the nerves innervating the nipple and areola are best protected if resections at the base of the breast and skin incisions at the medial areolar border are avoided. (Plast. Reconstr. Surg. 105: 905, 2000.)
Preservation of the sensitivity of the nipple and areola is an important goal in breast surgery. Yet, only scant and contradictory information about the course and distribution of the supplying nerves is available in the literature. Although most authors agree that the nipple and areola are innervated by the lateral and anterior cutaneous branches of the intercostal nerves, there is a controversy about which intercostal nerves are involved and which course they take through the breast parenchyma. So far, the 2nd, 3rd, 4th, and 5th 1 or the 2nd, 3rd, 4th, 5th, and 6th 2 or the 3rd, 4th, and 5th 3-5 or the 4th, 5th, and 6th 6,7 or only the 4th 8-12 intercostal nerves have been described as supplying nerves to the nipple and areola. The 4th lateral cutaneous branch is unanimously regarded as the most important nerve for the sensitivity of the nipple; however, its course from the point where it perforates the deep fascia in the midaxillary line to the nipple has been described controversially. Some authors describe it as passing deeply through the breast tissue,3,5,9,11 some describe a more superficial course close to the skin, 1,2,4,8 and others do not give any details about its course at all. 6,7,12
These controversial reports might be due to the difficulty in dissecting the thin nerves and to frequent anatomic variations that bias the results if the investigation is carried out only in a small number of cadavers. We undertook this anatomic study to clarify these controversial reports and to enable the preservation of the sensitivity of the nipple and areola during breast surgery.