A Cadaveric Study of the Dorsal Nerve of the Clitoris: Mapping a 3D Danger Zone for Female Cosmetic Genital Surgery

Abstract

Introduction The Dorsal Nerve of the Clitoris (DNC) innervates the clitoris and plays a major role in female sexual arousal. However, little research investigating the location of its terminal branches places them at risk of being severed during surgical procedures. For instance, the most common labiaplasty approach begins with an incision into the prepuce surrounding the glans clitoris. This area may house terminal branches of the DNC, leading to damage if severed. In this study we measured the distances of distal DNC branches from important surgical landmarks, as well as created a three-dimensional “danger zone,” which can be used by surgeons performing female cosmetic genital surgery. Methods A total of 19 female preserved cadavers were examined, yielding 38 DNC. The DNC was located by first making a shallow vertical incision from the pudendal cleft superiorly through the mons pubis. The body of the clitoris was located and the fascia surrounding the crura within the labia minora was carefully dissected to expose the DNC. The DNC was followed to its deepest point at the penetration of the perineal membrane, and was also followed superficially over the angle of the clitoris and toward the glans. The distal branches were carefully dissected to reveal the location at which the nerves penetrate the clitoris. Care was taken to not disturb the natural position and course of the nerves. Photographic evidence of each nerve was obtained, and various depth measurements were taken with Mitutoyo Absolute IP-67 digital calipers. Statistical analysis was conducted in Microsoft Excel. Results The distance from the distal-most DNC branch to the edge of the prepuce surrounding the clitoris was the most important and surprising measurement we obtained in this study. The mean distance was 10.80 mm (SD 5.31 mm). These terminal branches extend into the subcutaneous tissue of the prepuce (Figure 1), which serves as the initial incision point in the most common approach to the labiaplasty procedure. Without the ability to visualize the small distal DNC branches, surgeons operating in this area have a high risk of severing the nerves that provide sensation to the clitoris. As such, this reveals that surgeons performing surgeries in this region should avoid techniques involving excision of the clitoral hood. Another important measurement was the mean distance of the DNC as it passed over the angle of the clitoris to the edge of the labia minora, which was 30.35 mm (SD 6.44 mm). This measurement provides an understanding of the depth that the DNC travels within the labia minora, which is also relevant to labia excision in the labiaplasty procedure. Conclusion This study demonstrates that the most distal branches of the DNC extend further than expected, and terminate subcutaneously within the prepuce of the clitoris. This study also reveals the depth at which the DNC travels compared to the labia minora, which is an important depth for surgeons performing procedures in this region. While there is still much to be understood about the course of the DNC, these measurements are an important beginning to increasing the awareness of this region for female sexual health.