Vascular architecture of human uterine cervix visualized by corrosion casting and scanning electron microscopy

In contrast to the uterine corpus, the vascular architecture of the human cervix has been the subject of only a few studies, mostly dealing with the ectocervical mucosal vessels. This study presents the vascular system of the cervical wall surrounding the endocervical canal visualized by the best currently available technique, corrosion casting combined with scanning electron microscopy. Uteri collected at autopsy (n 20) were perfused via afferent vessels with fixative followed by Mercox resin and corroded after polymerization of the resin. The obtained vascular casts of the cervix visualizing all vessels including capillaries were examined in the scanning electron microscope. The vascular system of the cervix was nearly completely replicated in only two (10) of the samples. In the wall of the cervix, four distinct vascular zones surrounding the endocervical canal were observed: (i) the outer zone containing larger vessels, arteries and veins of 0.31 mm diameter; (ii) the zone containing arterioles and venules; (iii) the zone of endocervical mucosal capillaries showing a very high density, parallel arrangement and relatively few interconnections and (iv) the innermost, subepithelial zone containing small veins running along the endocervical canal. Despite the loss of the delicate ectocervical mucosal vessels from the cast during the corrosion step, we have successfully visualized the majority of the cervical vasculature. The vascular pattern of the human cervix, especially that of the endocervical mucosa, may facilitate the adaptation of the cervical vasculature to the extensive remodeling of the cervix during parturition.