Citation, DOI, disclosures and article data
At the time the article was created Laura Smith had no recorded disclosures.View Laura Smith's current disclosures
The lesser sac or omental bursa is a potential peritoneal space within the abdomen, part of the peritoneal cavity.
The lesser sac may be conceptualized as the space posterior to the lesser omentum, between the posterior wall of the stomach and the surface of the peritoneum that covers the anterior surface of the left kidney 1.
The epiploic foramen (of Winslow) is the only natural communication between greater and lesser sacs 3.
As the lesser sac is a peritoneal space, all of its boundaries are lined by visceral or parietal peritoneum 3. On the left side, the lesser sac is partially divided by a peritoneal fold over the left gastric fold, named pancreatogastric fold 3.
visceral peritoneum along the posterior surface of the stomach
gastrocolic omentum (between greater curvature of the stomach and transverse colon)
epiploic foramen (of Winslow) communicating with greater sac
visceral/parietal peritoneum that covers the diaphragm, pancreas, left kidney/adrenal gland, and duodenum
transverse mesocolon (between the transverse colon and anterior surface of the pancreas)
peritoneum covering the caudate lobe of the liver
superior (hepatic) recess - between caudate lobe of liver and diaphragm; it is partially separated from splenic recess by gastropancreatic fold
splenic recess - between splenic ligaments and stomach
inferior (omental) recess - between the stomach and transverse colon
The lesser omentum is composed of two peritoneal ligaments that extend from the lesser curvature of the stomach and duodenal bulb to the liver, the gastrohepatic, and hepatoduodenal ligaments, respectively. During embryologic development, the rotation of the stomach relative to the liver causes redundancy in the mesentery about the stomach.
As the greater curvature of the stomach rotates anterolaterally, a recess is formed between the redundant dorsal peritoneal ligament connecting the greater curvature of the stomach to the dorsal abdominal wall. Simultaneously, the lesser curvature of the stomach rotates posteromedially, and the ventral peritoneal ligament between stomach and liver becomes the lesser omentum, an incomplete boundary separating the main peritoneal cavity (greater sac) from the posterior recess (lesser sac).