[Disturbance of sexual function after an operation for rectal cancer and a fundamental study of the relationship between autonomic nerves and arteries in the pelvis of dogs].

Clinical studies of 15 male patients with resected rectal cancer and 30 canine experiments revealed a close relationship between autonomic nerves and arterial flow in the pelvis. In clinical cases transection of the hypogastric nerve (HGN) and the sympathetic trunk did not affect the erectile function in the postoperative course. In animal experiments transection of these nerves did not affect the increase in inner pressure of the penis cavernosum. Internal pudendal arterial (IPA) flow affecting the erectile function was decreased by transection of the bilateral pelvic splanchnic nerve (PSN). Transection of the PSN on one side did not affect the erectile function. In postoperative cases in which only one side of the lower grade branches of the PSN were preserved, the erectile function was preserved. In animal experiments in which the PSN of one side was disturbed, the IPA flow of the same side decreased, while the flow of the other side increased. The effect of norepinephrine hydrochloride on canine vascular smooth muscle was examined in vitro. Vascular smooth muscle strips from the IPA, relaxed longitudinally. This relaxation was suppressed by phentolamine methylate (alpha-blocker). It is also conceivable that the erectile function through the PSN is controlled by the sympathetic nerve, not by the parasympathetic nerve.