Pudendal Nerve Entrapment

Our anatomic findings have led us to define conflictual relations that may be encountered in their course by the pudendal n. and its branches. Starting from the clinical study of a group of patients suffering from chronic perineal pain in the seated position, we have defined, beginning with the cadaver, three possible conflictual settings: in the constriction between the sacrotuberal and sacrospinal ligaments; in the pudendal canal of Alcock; and during the straddling of the falciform process of the sacrotuberal ligament by the pudendal n. and its branches. Consequently, considering so-called idiopathic perineal pain as an entrapment syndrome, the clinical and neurophysiologic arguments and infiltration tests have led us to define a surgical strategy which has currently given 70% of good results in 170 operated patients. Earlier diagnosis should improve on this. Allocated to different specialists, patients suffering from chronic perineal pain represent a dispersed group and undergo the failure of different local treatments: proctologic, urologic or gynecologic. However, their history is quite uniform: they have unior bilateral pain in the territory of the pudendal n. and this pain is exacerbated, if not entirely provoked, by the seated position. This postural nature of this pain in a particular territory led us to seek a compression syndrome of the nerve trunk. Thus, based on the convergent clinical features of a truncal pathology, we decided over 10 years ago to study the course of the pudendal n. and to deduce a physiopathologic explanation for certain pains which are often wrongly labeled as psychogenic. Material and methods [9] Anatomic study Twelve subjects were dissected on both sides: 6 men and 6 women. This dissection was made on fresh cadavers and on formolised specimens. Initially, sagittal sections of the pelvis were made so that the n. could be followed throughout its course and the distribution of its collateral and terminal branches studied. Then, dissections by a transgluteal approach were carried out.