The superior hypogastric plexus is a cluster of nerves and nerve fibers lying in front of the fifth lumbar vertebra, a little to the left side, under the site where the aorta splits to travel down to the legs.
The nerves branch to the left and right and descend into the pelvis, supplying the organs of the pelvic cavity including the bladder, prostate, uterus, and vaginal area.
The hypogastric plexus nerve block is done for pelvic pain that has not responded to other nerve blocks or medications, especially intractable pain caused by cancer in the organs of the pelvic cavity. The pain fibers of this plexus of nerves pass lower than the spinal cord, therefore, regular epidural blocks do not provide adequate pain relief for this type of pain.
The procedure is commonly done with intravenous sedation. The sedation will not put the patients completely to sleep, but relaxes patients so they may tolerate the procedure with a minimum level of discomfort.
The procedure is done by the physician by placing a needle through the lower back under x-ray or ultrasound guidance to ensure proper needle placement. A local anesthetic is used to numb the skin before the needle is inserted.