Lesser omentum hernia

　　First, the cause of the disease

　　1. There is a normal or abnormal cleft between the lesser omentum sac and the abdominal cavity, which is the anatomical basis of the lesser omentum hernia. For example, if the Winslow hole is too large, or if there is abnormal development or local weakness and defect in the mesentery of the small intestine or transverse colon mesentery.

　　2. The excessive mobility of the intestine The excessive mobility of the intestine is another important condition for it to herniate through the lesser omentum foramen. Common causes of excessive intestinal mobility include:

　　(1) Long mesentery of the small intestine. Usually, the intestine with a large degree of mobility in the abdominal cavity is the small intestine. Under the condition of long mesentery, its abnormal mobility must be increased, so the organs that are herniated clinically are mostly the small intestine.

　　(2) Congenital malrotation of the intestine: Malrotation of the intestine can be accompanied by poor fixation of the midgut, becoming an important cause of intra-abdominal hernia.

　　3. Abnormal peristalsis and sudden increase in intraperitoneal pressure, like other intra-abdominal hernias, can cause an increase in the weight of part of the intestinal tract after abnormal peristalsis or overeating. Under the influence of sudden changes in the patient's position and sudden increases in intraperitoneal pressure, the intestinal tract is prone to herniate into the lesser omentum sac through the Winslow hole, forming a lesser omentum hernia.

　　II. Pathogenesis

　　1. Pathogenic process The lesser omentum is a double-layered peritoneum connecting the porta hepatis with the lesser curvature of the stomach and the upper part of the duodenum, which can be divided into two parts: the right hepaticoduodenal ligament and the left hepatogastric ligament. The only passage for the omentum sac to communicate with the great abdominal cavity is the omental foramen (Winslow's hole). The anterior boundary of Winslow's hole is the hepatoduodenal ligament, the posterior boundary is the parietal 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 part of the duodenum. It is generally passable for 1 to 2 fingers, and it is the most susceptible part for the hernia sac of the lesser omentum. If it is too large due to some reason, it provides a 'hernia gate' for the herniation of the intestinal tract. Some people believe that a large Winslow's hole, which can pass through or accommodate more than two fingers, is the primary condition for the formation of Winslow hernia.

　　The omentum is a double-layered peritoneum that originates from the greater curvature of the stomach and extends downward from the beginning of the duodenum. The double-layered omentum extending downward from the greater curvature of the stomach is adherent to the transverse colon to form the gastrocolic ligament; the omentum folds upwards at the umbilical level (forming the posterior two layers of the omentum) to the transverse colon and wraps it separately, thereby forming the transverse colon mesentery. These two places may develop into weak areas or clefts due to incomplete fusion or regression of the omentum during embryonic development, or due to local ischemic lesions, providing a pathological channel for the entry of abdominal organs and tissues into the lesser omentum sac after birth.

　　When the mesentery of the small intestine is too long or there is congenital malrotation of the intestine, the mobility of the intestinal tract increases, increasing the opportunity for herniation into Winslow's hole and other clefts. The former is mainly small intestinal hernia, while congenital malrotation of the intestine can be accompanied by poor fixation of the midgut, manifested as incomplete attachment of the mesentery, free ascending colon, high cecum, incomplete attachment of the omentum, and enlarged duodenal recess, etc. pathological changes. Therefore, in addition to causing intestinal torsion, it can also lead to the omentum, right colon, and transverse colon herniating into the lesser omentum sac through Winslow's hole, especially when the omentum is not attached, the right colon is not fully descended, and/or the mesentery is too long, it is more likely to occur.

　　The anterior wall of the hernia ring of the lesser omentum hernia is the hepatoduodenal ligament, which contains the common bile duct, portal vein, and hepatic artery, with the inferior vena cava and spine behind. This structure is strong and has little expansibility, which is easily compressed by the intestinal tract passing through the hernia ring, making it difficult to return, and prone to cause incarceration and strangulation of the hernia contents.

　　2. Pathological classification According to the different paths by which the intestinal loops herniate into the lesser omentum sac, there can be 4 types.

　　(1) Winslow hernia: The hernia where abdominal organs enter the lesser omentum sac through Winslow's hole is called Winslow hernia, also known as lesser omentum hernia. This condition was first reported by Blandin (1834) and, according to statistics, accounts for 0.08% of all hernias and 8% of internal hernias. It is extremely rare in clinical practice, more common in males, with 63% of the hernia contents being small intestine, 30% being terminal ileum and/or cecum, 7% being transverse colon, and a very small number being gallbladder and omentum. Reviewing the literature, only 2 cases have been reported in China. Due to the lack of specific manifestations, less than 10% of patients are diagnosed or suspected of having the disease before surgery, with a mortality rate as high as 49%.

　　(2) Transverse colon mesentery defect hernia: The small intestine herniates into the omental bursa through the transverse colon mesentery defect.

　　(3) Hepatogastric ligament defect hernia: The intestinal defect herniates into the omental bursa.

　　(4) Gastrocolic ligament defect hernia: The small intestine herniates into the omental bursa through the gastrocolic ligament defect.

　　1. Intestinal strangulation

　　The anterior wall of the hernial ring of Winslow's hernia is the hepatoduodenal ligament, which is strong and has little expansibility. The herniated contents are easily compressed, leading to incarceration and strangulation.

　　2. Obstructive jaundice

　　The anterior wall of the hernial ring of Winslow's hernia is the hepatoduodenal ligament, which is strong and has little expansibility. The herniated contents are easily compressed, leading to incarceration and strangulation.

　　1. Symptoms

　　This disease is mainly manifested as acute intestinal obstruction, with symptoms such as upper abdominal pain, vomiting, and cessation of defecation and flatus.

　　1. Abdominal pain

　　Presenting as acute onset of colicky pain, it is often severe and unbearable. Due to the relative relaxation of the anterior wall of the hernial ring (hepatoduodenal ligament) when the patient's body is flexed, abdominal pain can be relieved, so the patient often adopts a sitting position, with the knees bent to the chin. Some scholars believe that the relief of abdominal pain when the body is flexed is a characteristic manifestation of Winslow's hernia, and some patients may feel pain in the lower back.

　　2. Vomiting and abdominal distension

　　The degree is related to the organ herniated, such as the small intestine, vomiting is more severe. If it is the omentum, vomiting can be mild. If the herniated organ is the upper segment of the jejunum, vomiting occurs early and frequently, and abdominal distension is generally not obvious; if the herniated organ is the ileum or colon, vomiting occurs later, and the degree of abdominal distension is also more obvious.

　　2. Physical examination

　　The patient's upper abdomen is full, and a soft cystic mass can often be felt on the left side of the upper abdomen. The mass is fixed with tenderness. Early percussion is tympanic, and after exudation, it is usually dull. Intestinal sounds may be hyperactive or a gurgling sound can be heard. If the intestinal sounds disappear, or there are symptoms of peritoneal irritation, or blood-stained turbid fluid is aspirated from the peritoneal cavity puncture, it indicates that the herniated intestine has become strangulated or necrotic. In severe cases, shock may occur, and a few patients may have obstructive jaundice due to compression of the common bile duct by the anterior wall of the hernial ring.

　　Choose healthy foods and beverages instead of high-fat, high-sugar, and high-calorie foods, eat more varieties of vegetables and fruits, whole grains, and legume foods, reduce the intake of red meat (beef, pork, and lamb), avoid eating processed meats, and limit the intake of high-salt foods. To prevent tumors, try not to drink alcohol. If you do drink, limit the daily drinking amount, with no more than 2 cups for men and no more than 1 cup for women.

　　1. X-ray examination

　　1. Standing or supine abdominal flat film

　　If the hernial content is the small intestine, an arc-shaped intestinal gas and liquid level can be seen in the omental bursa area, and it may cause the left anterior displacement of the stomach. In the right lower quadrant, it may be seen that the small intestine loops rise to the subhepatic Winslow's hole. If the hernial contents include the ascending colon, there may be no visible intestinal gas and fecal shadow in the right lower quadrant. However, in the report of 19 cases of omental bursa hernia by Erskine, 13 cases had no obvious gas-liquid level in the omental bursa area.

　　2. Upper Gastrointestinal Contrast

　　It can show that the stomach is pushed to the left, and the delayed contrast shows that the intestinal tract is located in the small omental sac.

　　3. Barium Enema

　　When the herniated object is the colon, it can show that the colon is displaced into the small omental sac.

　　4. CT Scan

　　The main signs include:

　　(1) The mesentery is located between the inferior vena cava and the portal vein.

　　(2) There is a gas-liquid level in the small omental sac, and it points to the omental foramen like a beak.

　　(3) There is no ascending colon on the right side of the abdomen.

　　(4) There are 2 or more intestinal loops in the subhepatic space.

　　2. Ultrasound Examination

　　Below the liver, at the orifice of the small omental sac, behind the common bile duct and portal vein, abnormal intestinal echoes can be seen in the area of the small omental sac.

　　3. 99mTc-HIDA Cholangiography

　　When the herniated object is the gallbladder, 99mTc-HIDA cholangiography can show the gallbladder and abnormal position of the bile duct.

　　In terms of diet, attention should be paid to reasonable nutrition, and food should be as diverse as possible. Eat more high-protein, high-sugar, and high-calorie foods, rich in vitamins and trace elements, as well as fresh fruits and vegetables. Eat more whole grains and legumes, reduce the intake of red meat (beef, pork, and lamb), avoid eating processed meats, limit the intake of high-salt foods, and avoid smoking and drinking.

　　Avoid staying up late and avoid increasing abdominal pressure.

　　1. Treatment

　　This disease is prone to cause strangulation and necrosis of the incarcerated intestinal tract, so once it is suspected to be caused by acute mechanical intestinal obstruction, timely surgical treatment should be performed.

　　During the process of intestinal reduction, if the herniated intestinal loop is not seriously incarcerated, it can be gently pulled to restore its position. If the obstructed intestinal tract is dilated and difficult to reduce, it can first be incised at the small omental sac, reduce the pressure in the incarcerated intestinal loop by reducing the pressure in the intestinal cavity, and then reduce it; or first incise and relax the lateral peritoneum of the descending duodenum, and fully mobilize the duodenum, expand the hernia ring (small omental foramen), and then reduce the incarcerated intestinal loop. After reduction, the retention or resection of the intestinal tract is determined according to its vitality. Then, the incision is sutured and (or) covered with omentum to close the hiatus and prevent recurrence.

　　2. Prognosis

　　There is no relevant content description at present.