Prevention of accidental trauma to the iloinguinal nerve during inguinal hernoirrhaphy.

The sensory component of the iloinguinal nerve normally courses through the inguinal canal and supplies the upper thigh, pubis, inguinal crease, and the anterior and lateral aspect of the scrotum or labia majora. In 424 inguinal dissections a normal course of these nerves was found in 60 per cent. In 35 per cent an aberrant origin, course, and position were found, in which the nerve was behind and within the cremaster covering of the spermatic cord or round ligament. In 5 per cent both a normal and aberrant course was encountered on the same side. Both normally or aberrantly positioned nerves may be compromised during operation by retraction or by accidental division during the exposure of the inguinal canal structures and the isolation and dissection of the hernial sac. However, an aberrant nerve has a greater risk potential since it is behind and within the cremaster layer of the spermatic cord or the homologous covering of the round ligament. Accurate identification of these nerves and the awareness of their variable course and position during operation should minimize the risk of postoperative peri-inguinal cutaneous changes. This aberrant course of the ilioinguinal nerve has not been previously reported in the literature.