The uterosacral complex: ligament or neurovascular pathway? Anatomical and histological study of fetuses and adults

The aim of this study was to define the anatomical relationships of the uterosacral ligament complex (USLC) and to analyze histologically its content. Three fetal and four adult cadavers were used. Anatomical dissections were carried out. Eight fresh biopsies (four fetal and four adult) of the USLC were analyzed histologically and immunohistochemically. Specimens were stained with hematoxylin eosin safran coloration, with anti-nervous cell antibodies (PS 100) and with anti-smooth muscle antibodies (to visualize vessel walls). By removing the visceral pelvic fascia, nervous fibers were found within the USLC forming the hypogastric plexus. Histologically, the USLC contained connective tissue, nervous fibers, sympathetic nodes, vessels, and fatty tissue. No structured ligamentous organization was identified. The uterosacral “ligament” is a “complex” integrating connective tissue as well as nervous and vascular elements. Radical excisions and USLC suspension during pelvic floor reconstructive surgery should be performed with caution in order to preserve pelvic innervation.