Digestive disorders

IV.1.1.: Stomach

Anatomical description of the stomach can be found in its entirety in Chapter III./1.

IV./1.2.: Omental bursa (lesser sac)

IV./1.2.1.: Topography

During development, a smaller part of the abdominal cavity gets behind the stomach - giving rise to the omental bursa (see the drawing). Originally, part of the right celomic cavity, which, as a result of the transposition and rotation of stomach, comes to lie dorsally to the stomach. Its borders are ventrally the lesser omentum (hepatogastric and hepatoduodenal ligaments), and the stomach; dorsally the posterior parietal peritoneum, covering the pancreas.

Drawing 1. Topography of the stomach and omental bursa in a horizontal abdominal section at the level of the middle of corpus ventriculi. The epiploic foramen (of Winslow), vestibule, and the superior and inferior recesses fall outside of the section level demonstrated in the figure. (yellow-peritoneal derivates of the right celomic cavity; blue-peritoneal derivates of the left celomic cavity)

A natural opening and entrance to the lesser sac, the epiploic foramen (of Winslow), is situated under the sharp right edge of the hepatoduodenal ligament. Its borders are: anteriorly the hepatoduodenal ligament, posteriorly the hepatorenal ligament, caudally the duodenorenal ligament, and cranially the lower limit of the caudate lobe of the liver. Indeed, the omental bursa is a vitual space enabling movements and distension of the stomach. Its clinical significance is associated with the surgical approach of pancreas, by getting into the omental bursa and by opening the dorsal parietal peritoneum, the pancreas, tightly apposed to the latter, can be reached.

Parts of the omental bursa

• - vestibule

• - cavity proper

• - splenic recess

• - superior recess

• - omental (inferior) recess.

IV.1.2.1.1.: The vestibule of omental bursa

This part of the cavity extends from the epiploic foramen as far as the gastropancreatic fold. Its borders are identical to those of the omental bursa itself. The constriction caused by the gastropancreatic fold (a.k.a. omental diaphragm) represents the narrowest part of the omental bursa, also separating the vestibule from the cavity proper. The gastropancreatic fold corresponds to a peritoneal fold raised by one principal branch of the celiac trunc, the left gastric artery.

IV./1.2.1.2.: Cavity proper (cavum proprium) of omental bursa

The cavity has a strange shape with three (in fetal age) and, later, two recesses. Its borders are anteriorly the hepatogastric ligament and the dorsal surface of stomach, as well as the gastrocolic ligament; caudally the transverse colon and transverse mesocolon; posteriorly the parietal peritoneum and the pancreas behind it. The recesses are as follows.

IV./1.2.1.3.: Splenic recess

This recess points at the spleen on the left side of omental bursa (see drawing). It is highly significant for the stomach, because the peritoneal ligaments forming its borders contain important blood vessels. The phrenicosplenic (or splenorenal) ligament contains the splenic artery, whereas the gastrosplenic ligament encloses the initial part of left gastro-omental artery, as well as the short gastric arteries.

IV./1.2.1.4.: Superior recess

This space extends between the inferior vena cava and the oesophagogastric junction as far as the left coronary ligament.

IV./1.2.1.5.: Omental (inferior) recess

Existing in fetal age only, this recess extends between the two double folds of the greater omentum way down its overhanging part. Later on, owing to the adhesion of peritoneal layers, it becomes occluded.