The prevertebral plexus enters the pelvis as two hypogastric nerves, one on each side, that cross the pelvic inlet medially to the internal iliac vessels (Fig. 5.63A). The hypogastric nerves are formed by the separation of the fibers in the superior hypogastric plexus, into right and left bundles. The superior hypogastric plexus is situated anterior to vertebra LV between the promontory of the sacrum and the bifurcation of the aorta.