The Pudendal Nerve and Its Branches in Relation to Richter's Procedure

Abstract

Objective: Variations in the branching pattern of the pudendal nerve (PN) have been described in the literature. This study investigated these variations in order to comment on a safe area for the placement of a Richter's stitch. Methods: Richter's procedure was performed on nine unembalmed female cadavers and followed by dissection. PN dissections were done on another 20 embalmed female cadavers. Variations in the branching pattern of the PN were noted and the distance between the Richter's stitch placed and the PN/or the inferior rectal nerve (IRN) measured. Results: The IRN entered the gluteal region as a separate structure in 6/29 cases. The separate IRN was found to pass between 4.1 and 14.45 mm medial to the ischial spine in 18/29 cases. In one case, the Richter's stitch was found to pierce the IRN. The distance between the stitch and the PN and/or the IRN ranged from 0 to 17.8 mm. Conclusions: To minimize the risk of nerve damage or entrapment, the Richter's stitch should be placed >20 mm from the ischial spine. This recommended area should be revised for different population groups, as variations might exist between groups.

Neuropatía del pudendo como causa de dolor pélvico

“…En la parte posterior de la fosa isquiorrectal, inmediatamente después de pasar el ligamento sacroespinoso, el nervio da su primera rama: el nervio rectal inferior, que penetra la fascia interna del músculo obturador para distribuirse en su territorio anal. 17,23 Mahakkanukrauh et al encontraron que en el 21% de las veces el nervio rectal inferior se origina independientemente de la raíz de S4 sin hacer parte del tronco del nervio pudendo. 13 La rama perineal penetra medialmente la fascia interna del músculo obturador deslizándose hacia la base del diafragma urogenital donde se bifurca en sus ramas terminales superficial y profunda.…”

Regional anesthesia guided by ultrasound in the pudendal nerve territory☆

“…In the posterior portion of the ischiorectal fossa, immediately after the sacrospinous ligament, the nerve branches for the first time, giving rise to the inferior rectal nerve, which penetrates the internal fascia of the obturator muscle in order to innervate its anal territory. 47,58 Mahakkanukrauh et al found that, in 21% of cases, the inferior rectal nerve arises independently from the root of S4 without being part of the pudendal trunk. 41 The perineal branch penetrates medially into the internal fascia of the obturator muscle, sliding towards the base of the urogenital diaphragm where it divides into its superficial and deep terminal branches.…”