What Is the Omental Foramen?

The omental hole, also known as the Winslow hole, is the only channel through which the omental sac passes right into the peritoneal cavity. The vertical diameter is 3cm, which can accommodate the middle finger. Its anterior border is the free margin of the hepatoduodenal ligament, its posterior border is the inferior vena cava and its anterior frontal peritoneum or hepatorenal ligament, its upper border is the caudate lobe of the liver, and its lower border is the upper border of the upper duodenum . The right subhepatic space, namely the liver and kidney crypts, is passed to the right, and the omental sac vestibule is opened to the left. The portal vein, extrahepatic biliary tract, and intrinsic hepatic artery pass through the hepatoduodenal ligament at the anterior border of the omental foramen. The omentum is the only channel between the omental sac and the peritoneal cavity.

The omental hole, also known as the Winslow hole, is the only channel through which the omental sac passes right into the peritoneal cavity. The vertical diameter is 3cm, which can accommodate the middle finger. Its anterior border is the free margin of the hepatoduodenal ligament, its posterior border is the inferior vena cava and its anterior frontal peritoneum or hepatorenal ligament, its upper border is the caudate lobe of the liver, and its lower border is the upper border of the upper duodenum. . The right subhepatic space, namely the liver and kidney crypts, is passed to the right, and the omental sac vestibule is opened to the left. The portal vein, extrahepatic biliary tract, and intrinsic hepatic artery pass through the hepatoduodenal ligament at the anterior border of the omental foramen. The omentum is the only channel between the omental sac and the peritoneal cavity.

Chinese name

Omentum

nickname

Winslow hole

Upper Bound

Hepatic tail lobe

Lower bound

Upper duodenum

Retinal reticular morphology

1. There are five types of omental hole shape: triangular type (36.67%), fissure type (30.00 ± 8.37%), circular type (26.67 ± 8.07%), elliptical type (3.33 ± 3.28%), and half-moon type (3.33) (3.28%). Except for newborns, fissures are more common.

2. The pore diameter of the omentum (maximum) is 3.99 ± 2.19 (1.80 ~ 8.00) mm, which is smaller than the measurement results of original scholars (7 ~ 10 mm).

3. The omentum is located between the T ₁₂ ~ L ₂ vertebrae, with the majority of the flat L ₁ vertebrae.

Omental Hernia-Common Omental Hernia

The free small intestine crest, sometimes the mesenteric long colon, enters the small omental sac through the omental pore (Winslo pore), called herniaoflesseromentalbursa, or herniaofepiplonicforamen. Because the anterior wall of the hernia sac is a hepatoduodenal ligament, most cases will be narrow. Occasionally, the intestinal loop may enter the small omentum sac from the gastrocolic ligament or a hole in the gastric ligament. Acute intestinal obstruction is the main clinical manifestation, which is characterized by upper body leaning forward or knee flexion to reduce abdominal pain.

1. Pathogenic process: The small omentum is a double-layered peritoneum connected between the hilum of the liver and the small curvature of the stomach and the upper part of the duodenum. In two parts, the only channel between the omentum sac and the large abdominal cavity is the omentum (Winslow hole). The anterior boundary of the Winslow hole is the hepatoduodenal ligament, the posterior boundary is the wall peritoneum covering the front of the inferior vena cava, the upper boundary is the caudate lobe of the liver, and the lower boundary is the upper duodenum. Small omental sac hernia is most likely to occur. If it is too large for some reason, it provides a "hernia port" for hernia in the intestine. Some people believe that the Winslow hole is too large to pass or accommodate more than 2 fingers, is the first condition for the formation of Winslow hole hernia. The greater omentum is a double-layered peritoneum that extends from the greater curvature of the stomach and downwards from the beginning of the duodenum. The double-layered great omentum that extends under the great curvature of the stomach and the transverse colon more and more constitute the gastrocolonic ligament; the greater omentum rises below the umbilical plane (the latter two layers forming the great omentum) to the transverse colon and surrounds it separately. Then the mesangium of the transverse colon is formed. The development of these two places in the embryonic stage can be caused by incomplete fusion or degeneration of the omentum, or due to ischemic lesions, resulting in weak areas or holes, providing pathological pathways for postnatal abdominal organs and tissues to enter the small omental sac. . When the small intestinal mesentery is too long or suffers from congenital intestinal malrotation, the mobility of the intestine will increase, increasing the chance of hernias entering the holes such as Winslow holes. The former is mainly small intestine hernia, while congenital intestinal malrotation can be accompanied by poor fixation of the midgut, which is manifested by incomplete intestinal mesentery adhesion, free cecum ascending colon, high cecum, inferior omentum attachment, and duodenal Pathological changes such as enlarged crypts, in addition to causing intestinal torsion, can also cause the greater omentum, right colon and transverse colon can also enter the small omentum sac through the Winslow foramen, especially incomplete omentum attachment, right colon Insufficiency and / or excessive mesangium are more likely to occur. The anterior wall of the hernia ring of the small omental hernia is the hepatoduodenal ligament, which contains the common bile duct, portal vein, and hepatic artery, and the inferior vena cava and spine. This structure is strong and small, and it is easy to compress the intestine through the hernia ring, making it difficult to recover, and easy to cause incarceration and strangulation of hernia contents.

2. Pathological classification: There are 4 types according to the path of intestinal diaphragmatic hernia into the small omental sac.

(1) Winslow hernia: The abdominal cavity organs enter the small omentum sac through the Winslow foramen, which is the Winslow hernia, also known as the small omental hernia. The disease was first reported by Blandin (1834). According to statistics, it accounts for 0.08% of all hernias and 8% of internal hernias. Clinically, it is very common in men. Hernia contents are 63% in the small intestine, 30% in the terminal ileum and / or cecum, 7% in the transverse colon, and very few in the gallbladder and omentum. Review of the literature, only 2 cases were reported in China. Because of no specific manifestations, the patient was diagnosed or suspected of having less than 10% of the disease before surgery, and the mortality rate was as high as 49%.

(2) Transverse mesenteric hiatal hernia: The intestinal canal enters the small omental sac from the transverse colonic hiatal hernia.

(3) A hiatal hernia of the hepatogastric ligament: The intestinal canal enters the small omentum sac from the hiatus of the hepatogastric ligament (small omentum).

(4) Gastric colon ligament hiatal hernia: The intestinal canal enters the small omentum sac from the gastrocolic ligament hiatus.