Uterovaginal Plexus

The uterovaginal venous plexus is a rich network of interconnected veins that surrounds the uterus and vagina. It is part of the extensive pelvic venous system in females and is responsible for draining blood from the uterus, vagina, and portions of the urinary bladder. This plexus lies within the broad ligament and communicates freely with neighboring venous plexuses, including the vesical, rectal, and ovarian plexuses. Its valveless structure facilitates venous communication but also allows for the potential retrograde spread of infection or malignancy.

Structure

The uterovaginal venous plexus is a dual venous network composed of the uterine and vaginal venous plexuses. These plexuses interconnect extensively and form a unified drainage system. The veins are valveless and often difficult to distinguish surgically due to their close proximity to surrounding structures and their plexiform arrangement.

• Type: Valveless, intercommunicating venous network
• Components: Uterine venous plexus and vaginal venous plexus
• Communications: Vesical, ovarian, rectal, and pudendal venous plexuses

Location

The uterovaginal plexus lies within the broad ligament of the uterus and extends laterally to the pelvic wall. The uterine portion surrounds the sides of the uterus and cervix, while the vaginal portion envelops the lateral walls of the vagina. Together, they drain into the internal iliac vein through various tributaries.

Function

• Venous Drainage: Drains venous blood from the uterus, vagina, and cervix
• Collateral Circulation: Communicates with multiple pelvic plexuses to equalize pressure and allow alternative venous routes
• Thermal and Hormonal Exchange: Assists in countercurrent exchange with adjacent arterial supply, particularly ovarian and uterine arteries

Drainage Pathway

• Uterovaginal plexus → Uterine and vaginal veins → Internal iliac vein → Common iliac vein → Inferior vena cava

Lymphatic Drainage

• Uterus: Primarily to external and internal iliac nodes; fundus to para-aortic nodes
• Vagina: Upper third to internal iliac nodes; lower third to superficial inguinal nodes

Clinical Significance

• Pelvic Congestion Syndrome: Engorgement of pelvic venous plexuses, including the uterovaginal plexus, may cause chronic pelvic pain
• Surgical Risk: Injury to this plexus during hysterectomy or vaginal surgery can lead to significant hemorrhage
• Pathway for Spread: Valveless veins may allow retrograde spread of pelvic infections or metastatic cancer cells