OBJECTIVE: Many researchers have different views on the origin and anatomy of the preperitoneal fascia. The purpose of this study is to review studies on the anatomy related to the preperitoneal fascia and to investigate the origin, structure, and clinical significance of the preperitoneal fascia in conjunction with previous anatomical findings of the genitourinary fascia, using the embryogenesis of the genitourinary system as a guide.
METHODS: Publications on the preperitoneal and genitourinary fascia are reviewed, with emphasis on the anatomy of the preperitoneal fascia and its relationship to the embryonic development of the genitourinary organs. We also describe previous anatomical studies of the genitourinary fascia in the inguinal region through the fixation of formalin-fixed cadavers.
RESULTS: Published literature on the origin, structure, and distribution of the preperitoneal fascia is sometimes inconsistent. However, studies on the urogenital fascia provide more than sufficient evidence that the formation of the preperitoneal fascia is closely related to the embryonic development of the urogenital fascia and its tegument. Combined with previous anatomical studies of the genitourinary fascia in the inguinal region of formalin-fixed cadavers showed that there is a complete fascial system. This fascial system moves from the retroperitoneum to the anterior peritoneum as the preperitoneal fascia.
CONCLUSIONS: We can assume that the preperitoneal fascia (PPF) is continuous with the retroperitoneal renal fascia, ureter and its accessory vessels, lymphatic vessels, peritoneum of the bladder, internal spermatic fascia, and other peritoneal and pelvic urogenital organ surfaces, which means that the urogenital fascia (UGF) is a complete fascial system, which migrates into PPF in the preperitoneal space and the internal spermatic fascia in the inguinal canal.

OBJECTIVE: 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.
CONCLUSIONS: 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.

Modern high-definition laparoscopy has often revealed new visions of the structures known for centuries, and discovery of new structures like \'rectusial fascia\', additional morphology of the \'preperitoneal fascia\' and multiple Retzius spaces greatly facilitated accurate and judicious dissection for seamless laparoscopic inguinal hernioplasty. Dr. N. Asakage\'s presentation of inguino-pelvic fascial anatomy and its embryology [Asakage N. Paradigm shift regarding the transversalis fascia, preperitoneal space, and Retzius\' space. Hernia 2018 Feb 27. https://doi.org/10.1007/s10029-018-1746-8 (Epub ahead of print)] is excellent and fascinating, albeit with certain reservations highlighted herein.