Omental foramen

Where is the omental foramen located and where does it lead?

A probe inserted into the omental foramen enters directly into the vestibule of the omental bursa (vestibulum bursae omentalis). This vestibule represents the rightmost part of the bursa, bounded superiorly by the caudate lobe of the liver, inferiorly by the duodenum, and posteriorly by the parietal peritoneum covering the inferior vena cava.

The omental bursa is slit-like and lies posterior to the stomach, forming the most isolated space of the upper peritoneal cavity. The omental foramen connects the general peritoneal cavity with the omental bursa.

What are the boundaries of the omental foramen?

The foramen has the following anatomical boundaries:

• Hepatoduodenal ligament (lig. hepatoduodenale) — bounds the foramen anteriorly. This ligament is the rightmost part of the lesser omentum and is located between the porta hepatis and the superior wall of the duodenal bulb.
• Parietal peritoneum and hepatorenal ligament (lig. hepatorenale) — bound the foramen posteriorly. The parietal layer in this region covers the inferior vena cava (v. cava inferior).
• Caudate lobe of the liver (lobus caudatus) — bounds the foramen superiorly.
• Duodenorenal ligament (lig. duodenorenale) and the superior part of the duodenum (pars superior duodeni) — bound the foramen inferiorly. The duodenorenal ligament is a broad fold of peritoneum between the lateral margin of the descending part of the duodenum and the right kidney.

Topography of adjacent structures

The hepatoduodenal ligament contains the common bile duct, common hepatic duct, cystic duct, and proper hepatic artery; the portal vein (v. portae) lies posterior to them and between them. Lymph nodes and anterior and posterior hepatic nerve plexuses are also located here.

Clinical and surgical significance

The omental foramen is important in pathological processes and surgical interventions:

• Containment of inflammation: In fibrinous inflammation, peritoneal layers can quickly adhere. As a result, the omental foramen closes with adhesions, completely isolating the omental bursa from the general peritoneal cavity. Purulent processes from a perforated gastric ulcer or purulent diseases of the pancreas may remain confined to the omental bursa.
• Spread of infection: In purulent inflammation, exudate from the primary source, such as the appendix or gallbladder, spreads through the peritoneal pathways, including the omental bursa.
• Temporary hemostasis in hepatic hemorrhage: A finger is inserted into the omental foramen, and the hepatoduodenal ligament is compressed between the edge of the foramen and the thumb, temporarily clamping the vessels.
• Drainage: In biliary tract surgeries, such as after retrograde cholecystectomy, a rubber drain and gauze packings are placed near the gallbladder bed and the omental foramen according to indications.

Connection with the omental bursa

The omental bursa is located posterior to the stomach. Its walls are formed by:

• Anteriorly: the posterior wall of the stomach, the lesser omentum, and the gastrocolic ligament (lig. gastrocolicum).
• Posteriorly: the parietal peritoneum covering the aorta, inferior vena cava, left suprarenal gland, left kidney, and pancreas.
• Superiorly: the caudate lobe of the liver and partially the diaphragm.
• Inferiorly: the transverse colon and its mesentery (mesocolon transversum).
• Left: the spleen and its ligaments.

In case of obliteration of the omental foramen, surgical access to the bursa is achieved by incising the gastrocolic ligament or through the mesentery of the transverse colon.

Class and exam questions

What else to study on this topic

• Omental bursa (bursa omentalis)
• Hepatoduodenal ligament (lig. hepatoduodenale)
• Caudate lobe of the liver (lobus caudatus)
• Peritoneum and its derivatives

Other topics in the "Anatomical Structures" section

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