Predictable Location of Breast Sensory Nerves for Breast Reinnervation.

The sensory innervation to the breast originates from the medial and lateral cutaneous branches of the third to fifth intercostal nerves, which are at risk for injury or loss during mastectomy. Providing reinnervation after mastectomy was introduced almost 20 years ago, but it is not widely performed, perhaps because of the difficulty of locating a recipient nerve. The authors have performed cadaveric dissections to allow for precise anatomical localization of the lateral intercostal branch providing breast sensation. Bilateral chest dissections were performed on 10 female cadavers. The lateral intercostal nerve providing sensation to breast tissue was identified. The distances from the sternum, the midclavicular line, and the lateral pectoralis minor-in addition to nerve diameter-were measured. The nerve was successfully identified bilaterally in all cadavers. The majority of nerves (16 of 20) exited from under the fourth rib. The average distance from the sternum was 13.1 ± 1.3 cm (range, 10 to 15 cm) and the average distance from the midclavicular line was 11.8 ± 2.2 cm (range, 8 to 16 cm). The nerve exited at the lateral border of the pectoralis minor or within 2 cm from the lateral border for all cadavers. The diameter of the nerve was consistently 2 mm. The nerve traveled under the thoracodorsal vessels, aiding in identification. The authors identified the predictable location of the lateral intercostal nerve providing sensation to the breast. The authors hope that by enabling surgeons to locate this nerve, more well-conducted studies will be performed investigating techniques and outcomes for breast reinnervation.