Space
Lesser sac (omental bursa)
Sliding peritoneal compartment behind the stomach
High-yield
The epiploic foramen provides the normal connection to the greater sac. Much of the pancreas lies behind the sac's posterior peritoneal wall rather than inside its cavity.
Overview
The lesser sac, or omental bursa, is a potential peritoneal compartment behind the stomach and lesser omentum. Its posterior surface overlies the pancreas and neighboring posterior abdominal structures. This arrangement allows the stomach to change position against a lubricated surface.
Reference facts
- Boundaries
- Anterior: posterior stomach, lesser omentum and gastrocolic region. Posterior: peritoneum over pancreas and adjacent retroperitoneal structures. Left: splenic attachments; superior: caudate/diaphragmatic region; inferior extent varies with omental fusion.
- Contents
- Normally contains a lubricating fluid film; superior, splenic and variably developed inferior recesses extend the potential space.
- Communications
- Communicates with the greater sac through the epiploic foramen behind the hepatoduodenal ligament.
Clinical correlation
Pancreatic fluid collections commonly occupy the lesser-sac region; a mature pseudocyst is one possible form, not the name for every acute collection. Posterior gastric perforation can also release contents here, with spread depending on local boundaries and adhesions.
Frequently asked questions
What are the boundaries of the lesser sac (omental bursa)?
Anterior: posterior stomach, lesser omentum and gastrocolic region. Posterior: peritoneum over pancreas and adjacent retroperitoneal structures. Left: splenic attachments; superior: caudate/diaphragmatic region; inferior extent varies with omental fusion.
What does the lesser sac (omental bursa) contain?
Normally contains a lubricating fluid film; superior, splenic and variably developed inferior recesses extend the potential space.
What does the lesser sac (omental bursa) communicate with?
The lesser sac (omental bursa) communicates with the communicates with the greater sac through the epiploic foramen behind the hepatoduodenal ligament.