Akiyo Matsumoto, MD, Kaida Arita, MD. Tsuchiura Kyodo General Hospital
Background: Disturbance of sexual function after an operation for rectal cancer has often occurred. The relationship between autonomic nerves and arteries in pelvis was examined.
Methods: Clinical studies of 15 male patients with resected rectal cancer were performed using Snap Gauge method, Penile-Brachial Index and evoked Bulvo-Cavernous Reflex. In 30 canine experiments, pelvic splanchnic nerve (PSN) electric stimulation, arterial flow measurement, corpus cavernosum pressure measurement and muscle strip study using drugs were evaluated.
Results: In clinical studies of 15 male patients, 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. In postoperative cases in which only one side of the lower grade branches of the PSN (S4) 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. We have evaluated the role of adrenergic components in the PSN on the erectile function in the dog. The effect of norepinephrine hydrochloride on canine vascular smooth muscle was examined in vitro. Vascular smooth muscle strips from the IPA relaxed longitudinally. Electrical stimulation of the PSN increased blood flow in the IPA and also elevated the cavernous pressure. These increases were blocked in part by phentolamine, but not by propranolol or atropine. The effects of cholinergic and adrenergic agonists and antagonists on mechanical responses were also examined in muscle strips obtained from various arteries in the intra-pelvic region including the IPA. Norepinephrine induced contraction in the iliac artery and relaxation in the IPA, and both the contraction and relaxation responses were blocked by phentolamine but not by propranolol. These findings suggest that in the dog, α-adrenergic components projected through the PSN may contribute to penile erection.
Conclusion: Blood flow in the IPA was controlled significantly by the same side PSN, but compensatory by the other side PSN. It is also conceivable that the erectile function through the PSN is controlled by the sympathetic nerve, not by the parasympathetic nerve. In postoperative cases in which only one side of the lower grade branches of the PSN (S4) were preserved, the erectile function was preserved.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 86099
Program Number: P264
Presentation Session: iPoster Session (Non CME)
Presentation Type: Poster
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