Innervation of the labia minora of prepubertal girls.

INTRODUCTION Surgical and histologic sources of information give little reference to innervation, vascular, and epithelial details of the labia minora. Little is known about areas of nerve density, epithelial qualities, and vascular compartments of the labial minora that contribute to sexual arousal and orgasm. Surgical procedure development and counsel about surgical risks related to labioplasty and surgical flaps created from labial tissue may be based on inadequate information. METHODS Labial samples from 10 normal girls (aged 2-9 years) who underwent surgery for labial fusion utilized waste tissue strips for immunohistochemical identification of S-100 and neuronal nitric oxide synthase (nNOS) in the labia minora. RESULTS Vascular and lymphatic plexus lie within the reticular dermis, which contains a dense mesh of nerve fibers with a higher concentration of nerve fiber at the level of the subepithelial plexus. Dense innervations are located at the epidermis, extending along the basal and spinous layers of the epithelium of labia minora. Nerve bundles in the papillary dermis are associated with sebaceous and eccrine glands and nerve terminals located throughout the epithelium. The introital epithelium of the labia minora is highly innervated with widespread and intense staining, detected in the introital border of the labia minora versus the external one. The dermis appeared to display S-100 and nNOS immunolabelling. S-100 was also immunopositive in the epidermis. CONCLUSION Labia minora is highly innervated along its entire edge. Related vascular compartment tissue involved in engorgement during sexual arousal makes this tissue important for sexual response. Labioplasty risks removal of tissue with an important contribution to sensory sexual arousal. Movement of labial tissue during genitoplasty may have different sensory outcomes dependent on which labial surface is used.