Electromicturition in Male Dogs at Pelvic Nerve Stimulation: An Urethrocystographic Study

Electromicturition released by stimulation of the pelvic nerves has been studied in 23 male mongrels. This course has been followed by measurements of the bladder pressure and urethrocystography with filmchanger and cinefluorography respectively. In order to investigate the influence of various nerves, muscles and erectile tissue on micturition, the experiment was varied as follows. The pudendal nerves were severed or stimulated. The pelvic nerves were cut proximal to the electrodes. The bulbocavernous muscle was cut. Chordotomy was performed in some dogs immediately before the examination. Sympathectomy was made 2-6 weeks prior to the study. Finally, angiography of the pudendal artery was accomplished with and without stimulation of the pelvic nerves. Electrical stimulation of the pelvic nerves always gives rise to a contraction of the detrusor. Simultaneously an antidromic stimulation of the external sphincter appears, complicating the micturition, which is clearly demonstrated during the first phase of electrostimulation. When the pudendal nerves have been cut, the external sphincter is relaxed and does not contract during the electromicturition. In the perineal portion of the urethra a long constriction slowly develops during the micturition giving rise to an obstacle for flow, towards the end of the micturition. This constriction is caused by a swelling of the erectile tissue around the urethra. Section of the pudendal nerves did not prevent this erection. Acute chordotomy, acute severing of the hypogastric nerves or long terme sympathectomy did not influence the results significantly. Neither did section of the bulbocavernous muscle influence the result. The conditions for electromicturition in male dogs is poor before section of the pudendal nerves but much better after these nerves have been cut. The application of electromicturition in male humans should be preceded by experiments in connection with bladder surgery.