Space
Retroperitoneum
Posterior extraperitoneal region with communicating tissue planes
High-yield
Kidneys and adrenal glands develop outside the peritoneal suspension. Most duodenum, pancreas and ascending/descending colon acquire posterior fixation during development, with familiar regional exceptions.
Overview
The retroperitoneum lies behind the posterior parietal peritoneum and in front of the posterior abdominal wall. It contains urinary organs, major vessels, nerves and portions of the digestive tract. Fascial layers subdivide it into spaces that influence how disease spreads.
Reference facts
- Boundaries
- Posterior parietal peritoneum anteriorly and posterior abdominal-wall fascia/muscles and spine posteriorly; extends beneath the diaphragm toward pelvic extraperitoneal tissue.
- Contents
- Kidneys, adrenal glands, ureters, aorta and cava with related nodes/nerves; most pancreas and duodenum, and usually ascending and descending colon, occupy associated compartments.
- Communications
- Tissue planes communicate with pelvic extraperitoneum, posterior hepatic/suprarenal regions and selected diaphragmatic pathways toward the thorax.
Mnemonic
Group the contents by task: urinary organs, great vessels and nerves, then the secondarily fixed digestive segments.
Clinical correlation
A retroperitoneal hemorrhage or leak may initially cause little peritoneal irritation despite substantial internal disease. The absence of guarding therefore does not indicate a small or harmless process.
Frequently asked questions
What are the boundaries of the retroperitoneum?
Posterior parietal peritoneum anteriorly and posterior abdominal-wall fascia/muscles and spine posteriorly; extends beneath the diaphragm toward pelvic extraperitoneal tissue.
What does the retroperitoneum contain?
Kidneys, adrenal glands, ureters, aorta and cava with related nodes/nerves; most pancreas and duodenum, and usually ascending and descending colon, occupy associated compartments.
What does the retroperitoneum communicate with?
Tissue planes communicate with pelvic extraperitoneum, posterior hepatic/suprarenal regions and selected diaphragmatic pathways toward the thorax.