Anatomical study of the ganglion impar

Abstract

Introduction: The sacral laterovertebral portions of the sympathetic chains (CSLS) are joined by an anastomotic loop anterior to the sacrococcygeal joint or to the first coccygeal vertebra. This results in the formation of the Ganglion Impar (GI). This one receives nociceptive projections and the sympathetic innervation of the distal viscera of the pelvis and perineum, being a target of nervous blockade for painful pathologies of the region.

Purpose: To study the frequency of formation, morphology, location and relations of the GI and thus provide the outfit that enables to approach the area with security.

Materials and methods: Thirty-seven cadaveric pelvic preparations were used, one of them sagittally sectioned, exclusively forphotographic mostration. The instruments used were: left handclamp, Metzenbaum and Iris scissors, handles and scalpel blades. Due to the deep location of the estructures, 3D photographs were taken.

Results Prevalence and location: The GI was found in 66.67% of the cases (24/36). Of these, in 50% (12/24) standing anterior to the transverse line between the fourth and fifth sacral vertebrae (high formation); and in 50% (12/24) at the level of the sacrococcygeal joint (low formation). Relations: The CSLS is deep to the interureteral lamina, to the presacral fascia and to the proximal attachments of the piriformis muscle (anterior to posterior). In the absence of GI, the nervous fillets pass between thea pex of the coccyx and the levator ani muscle, being related to the lateral sacral vessels.If it is presented, the GI rests on the middle sacral vessels, both of which are contained in separate sheaths. Relationship: The relationships differ according to the training height. Morphology of the GI. Of the total cases, 29.17% presented a rectangular shape, 12.5% triangular, and 58.33% plexiform. Approaches: The approaches were performed at the level of the midline, these being: transsacrococcygeal, intercoccygeal and anococcygeal.

Conclusion: We conclude that the formation of the ganglion is prevalent, and the predominant morphology is the plexiform. It should be remarked that all the elements of the presacrococcygeal region lie behind the presacral fascia. We consider that the safest approach is through the transsacrococcygeal joint.vThe knowledge of the anatomy and the relationships of the GI is extremely important to make approaches to it.