Purpose To investigate the urogenital fascia (UGF) anatomy in the inguinal region, to provide anatomical guidance for laparoscopic inguinal hernia repair (LIHR). Methods The anatomy was performed on 10 formalin-fixed cadavers. The peritoneum and its deeper fascial tissues were carefully dissected. Results The UGF’s bilateral superficial layer extended and ended in front of the abdominal aorta. At the posterior axillary line, the superficial layer medially reversed, with extension represented the UGF's deep layer. The UGF's bilateral deep layer medially extended beside the vertebral body and then continued with the transversalis fascia. The ureters, genital vessels, and superior hypogastric plexus moved between both layers. The vas deferens and spermatic vessels, ensheathed by both layers, moved through the deep inguinal ring. From the deep inguinal ring to the midline, the superficial layer extended to the urinary bladder’s posterior wall, whereas the deep layer extended to its anterior wall. Both layers ensheathed the urinary bladder and extended along the medial umbilical ligament to the umbilicus and in the sacral promontory, extended along the sacrum, forming the presacral fascia. The superficial layer formed the rectosacral fascia at S4 sacral vertebra, and the deep layer extended to the pelvic diaphragm, terminating at the levator ani muscle. Conclusion The UGF ensheaths the kidneys, ureters, vas deferens, genital vessels, superior hypogastric plexus, seminal vesicles, prostate, and urinary bladder. This knowledge of the UGF’s anatomy in the inguinal region will help find correct LIHR targets and reduce bleeding and other complications.

Background Controversies regarding the anatomical structure of Denonvilliers’ fascia and its relationship with surrounding fasciae have sparked a heated discussion, especially concerning whether Denonvilliers’ fascia is multilayered. This study aimed to expound on the anatomical structure of Denonvilliers’ fascia and its correlation with the peritoneum from the sagittal view and clarify the complex fascial relationship. Methods Our study was performed on 20 adult male pelvic specimens fixed in formalin, including 2 entire pelvic specimens and 18 semipelvic specimens. The local adjacent organs and fasciae were dissected, and Denonvilliers’ fascia was observed and removed for histological examination. Results Denonvilliers’ fascia was typically single-layered and tough. On the sagittal plane, the peritoneum constituting the peritoneal reflection and Denonvilliers’ fascia formed a “Y” shape. Denonvilliers’ fascia originated from the peritoneal reflection, extended along the ventral side of the seminal vesicles and prostate, continuing caudally; its bilateral sides closely connected to the urogenital fascia (UGF) of the pelvic wall. In addition, histology preliminarily indicated that the basal cell layers of the peritoneum and Denonvilliers’ fascia were continuous and formed a “Y” shape. Furthermore, the basal cells of the two peritonea extended to Denonvilliers’ fascia, creating a fused double-layered structure. Some tiny blood vessels or a network of such vessels extended from the peritoneum to Denonvilliers’ fascia. Conclusion Denonvilliers’ fascia, the extension of the peritoneum in the pelvic floor, appears as a single-layered “Y”-shape on the sagittal plane. Our study provides new support for the peritoneal fusion theory. Understanding the anatomical characteristics of Denonvilliers’ fascia and its relationship with the UGF is of guiding significance for inexperienced colorectal surgeons to conduct rectal cancer surgery.

Background The architecture of retrorectal fasciae is complex, as determined by different anatomical concepts. The aim of this study was to examine the anatomical characteristics of the inferomedial extension of the urogenital fascia (UGF) involving the pelvis to explore its relationship with the adjacent fasciae. Furthermore, we have expounded on the clinical application of UGF. Method For our study, we examined 20 adult male pelvic specimens fixed in formalin, including 2 entire pelvic specimens and 18 semipelvic specimens. Our department has performed 466 laparoscopic rectal cancer procedures since January 2020. We reviewed the surgical videos involving UGF preservation and analyzed the anatomy of the UGF. Results The bilateral hypogastric nerves ran between the visceral and parietal layers of the UGF. The visceral fascia migrated ventrally at the fourth sacral vertebra, which formed the rectosacral fascia together with the fascia propria of the rectum; the parietal layer continually extended to the pelvic diaphragm, terminating at the levator ani muscle. At the third to fourth sacral vertebra level, the two layers constituted the lateral ligaments. Conclusion The double layers of the UGF are vital structures for comprehending the posterior fascia relationship of the rectum. The upper segment between the fascia propria of the rectum and the visceral layer has no evident nerves or blood vessels and is regarded as the " holy plane” for the operation.