Anatomic basis for the innervation of the male pelvis

To reach an optimal outcome after radical prostatectomy or cystoprostatectomy, minimal bleeding from the dorsal vein complex, meticulous apical dissection without distraction of the rhabosphincter and preservation of the cavernous nerves are necessary. A total of 19 male cadavers were used, ranging in age from 52-78 years and including 8 fetuses. Fourteen complete pelves and five tissue blocks of prostate, rectum, membranous urethra and the rhabdosphincter were investigated. Besides anatomical preparations, the lower urinary tract was studied by means of serial histological sections. The cavernous nerves and the pudendal nerves as well as their branches were dissected. For this reason,the pubic symphysis was severed. Subsequently the right or left hip bone was removed, whereas the pelvic organs were left intact to achieve a complete exposure of the lower urinary tract and the pudendal nerves. The rhabdosphincter presents as a vertical structure extending from the bulb of the penis to the region of the bladder neck along the prostate and the membranous urethra. It is supplied by branches of the pudendal nerve after leaving the pudendal canal. The membranous urethra is innervated by branches of the autonomic pelvic plexus. The nervous branches that are responsible for erection travel along the lateral aspects of the prostate in the so called neurovascular bundle and traverse through the urogenital hiatus to reach the corpora cavernosa.