Quantitative anatomical study of male pelvic autonomic plexus and its clinical potential in rectal resection

The pelvic autonomic nerves innervate the pelvic viscera, and carry a high risk of damage during surgery. This high risk has been ascribed to the complex interrelationship of pelvic paravisceral structures and the difficulty in identifying particular structures, despite the fact that the anatomic characteristics of the pelvic autonomic plexus have been well documented. We dissected ten male embalmed adult cadavers with particular attention to the quantitative parameters of the pelvic plexus and its subsidiary plexus. The right inferior hypogastric plexus and its rectal branch were found to be significantly longer and wider than the left one, while the transverse diameter of the vesical and prostatic branches of the left side was significantly larger the right. The inferior mesenteric plexus gave off fibers directly to form the pelvic plexus in four of 20 hemipelves (20%). In the side-by-side comparison, the distance to midpoint of the sacral promontory of the left rectal plexus was significantly longer than that of the right, whereas the maximum length (the length of the longest nerve fiber from origin to corresponding organ) of the left vesical plexus was significantly shorter than that of the right. Additionally, the craniocaudal and dorsoventral diameters of the right pelvic autonomic plexus were significantly shorter those of the left. The quantitative parameters relating to the pelvic autonomic plexuses not only can enhance our understanding of its anatomy and function, but can also be used as references for surgical procedures and robot-assisted surgery.