The broad ligaments are two winglike structures that extend from the lateral uterine margins to the pelvic sidewalls. Each broad ligament consists of a double-layer drape of peritoneum. The anterior and posterior layers of this drape are termed the anterior and posterior leaves, respectively. In forming the broad ligament, this peritoneum folds over structures extending from each cornu. Peritoneum that folds over the fallopian tube is termed the mesosalpinx, that around the round ligament is the mesoteres, and that over the ovarian ligament is the mesovarium. Peritoneum that extends beneath the imbriated end of the fallopian tube toward the pelvic wall forms the suspensory ligament or the infundibulopelvic ligament of the ovary. This contains nerves and the ovarian vessels, and during pregnancy, these vessels, especially the venous plexuses, are dramatically enlarged. Speciically, the diameter of the ovarian vascular pedicle increases from 0.9 cm to reach 2.6 cm at term (Hodgkinson, 1953).
The cardinal ligament-also called the transverse cervicaliligament or Mackenrodt ligament-anchors medially to the uterus and upper vagina. The cardinal ligament is the thick base of the broad ligament. As such, during cesarean hysterectomy, sturdy clamps and suture are required for its transection and ligation.
Each uterosacral ligament originates with a posterolateral attachment to the supravaginal portion of the cervix and inserts into the fascia over the sacrum, with some variations (Ramanah, 2012; Umek, 2004). These ligaments are composed of connective tissue, small bundles of vessels and nerves, and some smooth muscle. Covered by peritoneum, these ligaments form the lateral boundaries of the pouch of Douglas.
The term parametrium is used to describe the connective tissues adjacent and lateral to the uterus within the broad ligament. Paracervical tissues are those adjacent to the cervix, whereas paracolpium is that tissue lateral to the vaginal walls.
During pregnancy, there is marked hypertrophy of the uterine vasculature, which is supplied principally from the uterine and ovarian arteries (see Fig. 2-10). The uterine artery, a main branch of the internal iliac artery-previously called the hypogastric artery-enters the base of the broad ligament. he uterine artery courses medially to the lateral side of the uterus. Approximately 2 cm lateral to the cervix, the uterine artery crosses over the ureter. This proximity is of great surgical signiicance, as the ureter may be injured or ligated during hysterectomy when the uterine vessels are clamped and ligated.
Once the uterine artery has reached the supravaginal portion of the cervix, it divides. The smaller cervicovaginal artery supplies blood to the lower cervix and upper vagina. The main uterine artery branch rurns abruptly upward and travels cephalad along the lateral margin of the uterus. Along its path, this main artery provides a branch of considerable size to the upper cervix and then numerous other medial branches serially penetrate the body of the uterus to form the arcuate arteries. As indicated by the name, each branch arches across the organ by coursing within the myometrium just beneath the serosal surface. Arcuate vessels from each side anastomose at the uterine midline. Radial artery branches originate at right angles from the arcuate arteries and travel inward through the myometrium, enter the endometrium/decidua, and branch there to become either basal arteries or coiled spiral arteries. he spiral arteries supply the funcrionalis layer. Also called the straight arteries, the basal arteries extend only into the basalis layer.