LAUSR

Background: Primary cadaveric studies were reviewed to give a contemporary overview of what is known about innervation of the female breast and nipple/nipple-areola complex. Methods: The authors performed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses–compliant systematic review and meta-analysis. The authors searched four electronic databases for studies investigating which nerve branches supply the female breast and nipple/nipple-areola complex or describing the trajectory and other anatomical features of these nerves. Inclusion criteria for meta-analysis were at least five studies of known sample size and with numerical observed values. Pooled prevalence estimates of nerve branches supplying the nipple/nipple-areola complex were calculated using random-effects meta-analyses; the remaining results were structured using qualitative synthesis. Risk of bias within individual studies was assessed with the Anatomical Quality Assurance checklist. Results: Of 3653 studies identified, 19 were eligible for qualitative synthesis and seven for meta-analysis. The breast skin is innervated by anterior cutaneous branches and lateral cutaneous branches of the second through sixth and the nipple/nipple-areola complex primarily by anterior cutaneous branches and lateral cutaneous branches of the third through fifth intercostal nerves. The anterior cutaneous branch and lateral cutaneous branch of the fourth intercostal nerve supply the largest surface area of the breast skin and nipple/nipple-areola complex. The lateral cutaneous branch of the fourth intercostal nerve is the most consistent contributory nerve to the nipple/nipple-areola complex (pooled prevalence, 89.0 percent; 95 percent CI, 0.80 to 0.94). Conclusions: The anterior cutaneous branch and lateral cutaneous branch of the fourth intercostal nerve are the most important nerves to spare or repair during reconstructive and cosmetic breast surgery. Future studies are required to elicit the course of dominant nerves through the breast tissue.