Surgical location and anatomical variations of pudendal nerve

An objective of our work was to clarify variations in pudendal nerve formation, as well as their possible impact on the clinical picture.

Bilateral pudendal nerve course and formation was studied on 20 adult cadavers. An anterior approach was used in 15 subjects, and both posterior and anterior approaches were used in five subjects.

The prefixed type plexus formation was observed in eight cases (40%). In these cases, S(1) and S(2) roots contributed to the formation of the pudendal nerve. In the postfixed type, the S(3) root was dominant in two cases (66.7%), and less the S(4) root in one case (23.3%), albeit to a lesser degree. Most commonly, the S(2) root participated in its formation in 17 cases (85%). The inferior rectal nerve penetrating the sacrospinous ligament was seen in one case, arising from the pudendal nerve before entering the pudendal canal in four cases. The dorsal nerve of the penis arose from the S(1) root in two cases (10%). We observed it branching before entering the pudendal canal in 15 cases (75%), and it had divided in the pudendal canal in the other cases. For the posterior access, the pudendal nerve was localized 13.1 ± 0.72 cm medial to the greater trochanter, 8.1 ± 0.72 cm above the ischial tuberosity, at a depth of 6.4 ± 0.32 cm.

This description may be useful when carrying out a pudendal nerve block and during surgical procedures carried out in this anatomical region.