3D micro-CT and immunofluorescence-based characterization of Denonvilliers' fascia and its neurovascular structures.

This study provides a comprehensive anatomical and histological characterization of Denonvilliers’ fascia (DVF) and its associated neurovascular structures using manual dissection, histology, three-dimensional micro-CT imaging, and immunofluorescence (IF) analysis. Five embalmed and three fresh cadavers (All males; mean age, 77.9 years) were examined, All specimens without any medical history of pelvic cavity deformation, pelvic trauma, or surgical interventions. Micro-CT and resin-embedded sections demonstrated that the DVF originates from the peritoneal reflection and consistently exhibits a multilayered architecture with division, compression, and fusion patterns depending on pelvic level. Nerve branches from the inferior hypogastric plexus (IHP) coursed along the DVF, accompanying the vessels. In a cadaver with colorectal cancer, the DVF identified pathological thickening and separation of fascial laminae. IF analysis from two fresh cadavers revealed the axonal composition of the IHP: 53.2% sympathetic (TH-positive), 21.9% parasympathetic (nNOS-positive), 18.2% sensory (CGRP-positive), and 6.7% unlabeled fibers. Parasympathetic fibers observed extensive myelination, whereas sympathetic fibers observed minimal overlap with MBP. These findings clarify the neural distribution in the DVF region and provide mechanistic insight into postoperative dysfunction. This integrated anatomical framework supports improved nerve-sparing strategies in rectal surgery.