Supracolic Compartment Anatomy

• The supracolic compartment is an anatomical space critical for clinicians, especially those specializing in the abdomen and pelvis.
• Recognizing anatomical spaces is useful for identifying pathologies during clinical examinations.

Supracolic Compartment

• It contains both patent and potential anatomical spaces.
• Borders, location, and contents are clinically relevant.

Greater Omental Sac

• The intricate folding of the midgut and hindgut leads to the convoluted nature of the peritoneal cavity.
• The greater omentum is a double membranous layer of peritoneum.
• It extends inferiorly from the greater curvature of the stomach.
• It covers the intestines and attaches superiorly to the transverse colon.
• Structures deep to the greater omentum are in the greater omental sac (greater sac).

Lesser Omental Sac

• The lesser omental sac (bursa) lies deep to the lesser omentum.
• The lesser omentum attaches along the lesser curvature of the stomach and the hepatic fissure of ligamentum venosum and the porta hepatis.
• Anteriorly, it is limited by the quadrate lobe of the liver, the gastrocolic ligament, and the lesser omentum.
• Posterior Limit is the parietal peritoneum.
• Deep to the parietal peritoneum is the left suprarenal gland, the superior part of the left kidney, the neck and body of the pancreas, and the diaphragm.
• Also related posteriorly are the abdominal aorta, celiac trunk and its branches, and the inferior phrenic arteries.

Superior Recess of Omental Bursa

• The lesser omental bursa continues superiorly into a superior recess.
• It extends cranially between the esophagus and the inferior vena cava.
• The left is limited by the left kidney and adrenal gland.
• The hepatoduodenal part transmits the portal triad (hepatic artery proper, bile duct, and hepatic portal vein) and forms the right anterior border.
• The inferior vena cava is located posteriorly to the right.
• The superior part of the duodenum inferiorly, and the caudate process of the caudate lobe of the liver superiorly to the right.
• Limitations create the epiploic foramen of Winslow, which communicates between the lesser and greater sacs.
• The transverse mesocolon attaches to the mesocolic taenia of the transverse colon, limiting the lesser omental bursa inferiorly.

Subphrenic Space

• The transverse colon divides the peritoneal cavity.
• The mesocolon divides the peritoneum into supracolic and infracolic compartments.
• The supracolic region houses the lesser omental bursa, subphrenic, and subhepatic spaces.
• The subphrenic space lies inferior to the diaphragm and superior to the liver.
• The falciform ligament of the liver divides it into right and left subphrenic spaces.
• The right space is limited posteriorly by the coronary ligament and relates to the anatomical right lobe of the liver.
• The left space is larger and has anterior and posterior segments.
• It relates to the anterior parts of the cardia and fundus of the stomach, the spleen’s diaphragmatic region, and the anterosuperior extent of the liver's left lobe.
• It is restricted posteriorly by the left triangular ligament and inferomedially by the lienogastric, lienorenal, and phrenicocolic ligaments.
• The latter three ligaments also aid in partially separating the subphrenic space from the left paracolic gutter.

Subhepatic Space

• The subhepatic spaces are below the liver and above the transverse mesocolon.
• The descending part of the duodenum forms the medial extent of the right subhepatic space (hepatorenal pouch of Morrison).
• The lateral boundary is the right lateral abdominal wall.
• Superiorly, the coronary ligament limits the space, while the anterosuperior part of the upper pole of the right kidney forms the posterior boundary.
• The left subhepatic space (lesser omental bursa) communicates with the right subhepatic space via the epiploic foramen of Winslow.

Clinical Significance

• Surgical intervention for organs in the lesser omental sac can be accessed through the gastrocolic part of the greater omentum.
• Additional access routes include the lesser omentum or transverse mesocolon.
• The right and left subphrenic spaces can accumulate fluid during pathological or postoperative processes.
• Fluid accumulation in the right subphrenic space is common after a right abdominal infection.
• The left subphrenic space is less likely to accumulate fluid after pelvic or lower abdominal surgery due to the inferior boundary formed by the lienogastric, lienorenal, and phrenicocolic ligaments.
• However, the left subphrenic space is more likely to have fluid build-up following upper abdominal surgery compared to the right subphrenic space.