Über die Morphologie der Rami viscerales plexus pudendi (Nn. pelvici) beim Menschen

Spinal cord segments controlling the canine vas deferens and differentiation of the primate sympathetic pathways to the vas deferens

This study was undertaken to explore the spinal cord segments controlling the canine and human vas deferens and differentiation of the mammalian sympathetic pathways to the vas deferens. Thoracolumbar white communicating rami (WCR) were electrically stimulated in the dogs. Stimulation of the 1st, 2nd, 3rd, and 4th lumbar WCR elicited an elevation of intraluminal pressure of the vas deferens in 2, 10, 16, and 14 of 20 dogs examined, respectively, whereas stimulation of sympathetic chain (between the 13th thoracic and 1st lumbar ganglia), 13th thoracic WCR, intermesenteric plexus, and 5th lumbar WCR showed no response in any of the 10, 2, 12, and 5 dogs examined, respectively. Anatomical study of the 118 human lumbar splanchnic nerves of 55 cadavers showed that almost all lumbar splanchnic nerves (96%) originated from L2 and/or L3 sympathetic chain ganglia (L1-2 spinal cord levels). Comparative anatomical study of the mammalian sympathetic pathways to the vas deferens showed that the caudal mesenteric plexus is not divided in rats, rabbits, cats, and dogs and is partially divided into two plexuses in monkeys and completely in humans and that separation of the sympathetic component in the pelvic nerve (isolation of the sacral splanchnic nerve) is in progress in the primate. These results indicate that spinal cord segments controlling the vas deferens are L1-4 in the dog and probably L1-2 in humans and that differentiation of the sympathetic nerve pathways is proceeding at both main and compensatory pathways to the vas deferens in the primate.

Anatomical basis of autonomic nerve-preserving total mesorectal excision for rectal cancer

Total mesorectal excision with autonomic nerve preservation for rectal cancer is based on the anatomy of the mesorectum and of the pelvic autonomic nerves. Cadaver dissections were performed to describe the relationship between these structures. Between the rectum and the sacrum a retrorectal space can be developed, lined anteriorly by the visceral leaf and posteriorly by the parietal leaf of the pelvic fascia. The hypogastric nerve runs anterior to the visceral fascia, from the sacral promontory in a laterocaudad direction. The splanchnic sacral nerves originate from the sacral foramina, posterior to the parietal fascia, and run caudad, laterally and anteriorly. After piercing the parietal layer of the pelvic fascia, approximately 4 cm from the midline, the sacral nerves run between a double layer of the visceral part of the pelvic fascia. The relationship between the hypogastric nerves, the splanchnic nerves and the pelvic fascia was comparable in all six specimens examined.

Lumbosacral sympathetic trunk as a compensatory pathway for seminal emission after bilateral hypogastric nerve transections in the dog

Seminal emission after transection of canine bilateral hypogastric nerves was investigated. Stimulation of severed hypogastric nerves caused full volume seminal emission (greater than four drops) in all six dogs examined. In contrast, stimulation of sympathetic trunks of other six dogs at the level of caudal mesenteric artery caused no emission in three dogs and a limited volume of seminal emission (less than one drop) by pressing the ampulla in the remaining. When hypogastric nerves were transected one month prior to the experiment, however, stimulation of sympathetic trunks in the same manner caused full volume of seminal emission in all six dogs. Distal dissection of sympathetic trunks demonstrated nerve fibers to the seminal tract via the pelvic splanchnic nerves. The results indicate that the seminal tract receives at least two sympathetic pathways; one from hypogastric nerves and the other from lumbosacral sympathetic trunks, and that the latter compensatorily generates seminal emission after hypogastric nerve transection.