Extraperitoneal fascia

The extraperitoneal fascia is a layer of loose connective tissue that lies between the transversalis fascia and the parietal peritoneum within the abdominopelvic wall.

It provides a flexible interface between the abdominal wall and the peritoneum. This fascia contains variable amounts of fat, as well as blood vessels, lymphatics, and nerves, allowing mobility of the peritoneum and accommodating changes in abdominal volume.

The extraperitoneal fascia is continuous throughout the abdominopelvic cavity but is described regionally as:

• Preperitoneal fascia: Located on the anterior abdominal wall, between the transversalis fascia and parietal peritoneum.

• Retroperitoneal fascia: Found posteriorly, between the posterior abdominal wall muscles and the parietal peritoneum; it encloses retroperitoneal organs such as the kidneys, adrenal glands, pancreas, and parts of the duodenum and colon.

• Endopelvic fascia: The inferior continuation of the extraperitoneal fascia into the pelvic cavity, supporting the pelvic viscera.

Functional importance

• Provides support and anchorage for blood vessels, lymphatics, and nerves supplying the abdominal organs.

• Allows movement and expansion of the peritoneum and viscera.

• Helps limit the spread of infection or fluid between compartments (especially in the retroperitoneal space).