The nerves of the inferior hypogastric plexus , which course on either side of the rectum , were probably damaged during the surgery. Erection depends on stimuli from parasympathetic neurons carried to the inferior hypogastric plexus primarily by the pelvic splanchnic nerves . Inasmuch as contraction of the bulbospongiosus and ischiocavernosus muscles contribute to maintenance of erection, the pudendal nerve may also contribute. Ejaculation and subsidence of erection are controlled by sympathetic nerves which enter the inferior hypogastric plexus from the hypogastric nerve and possibly the sacral trunk .
Lymphatic metastases are likely to appear in the pararectal, internal iliac , or sacral lymph nodes.
Blood-borne metastases are commonly found in the liver, lungs, and bones primarily, but also in the serosal membrane of the peritoneal cavity, the brain, and other locations. Recall that blood drainage from the inferior and middle rectal veins is to the internal iliac veins and the inferior vena cava, and drainage from the superior rectal vein is through the inferior mesenteric vein and the portal system. A twenty-six year old male presents to the E.R. after a motorcycle vs. car accident. The patient is awake and alert, and reports pain in his abdomen and pelvis. Examination also reveals abrasions on his abdominal wall surface and no signs or presence of blood on his external urethral meatus .