Intra-abdominal adhesions causing intestinal obstruction are common and frequent, accounting for about 40% of the total number of intestinal obstruction, which are not only easy to recur, but also have more complications, so the prevention and treatment of intestinal adhesions have always been a concern for surgeons. I. Etiology and pathogenesis Intra-abdominal adhesions, except for a very few congenital factors in the abdominal cavity, such as congenital developmental abnormalities or fetal fecal peritonitis, are mainly caused by acquired factors, commonly caused by abdominal inflammation, injury, bleeding, intra-abdominal foreign bodies, abdominal radiation and intra-abdominal injection of chemical therapy (chemotherapy). Intra-abdominal inflammatory diseases such as tuberculous peritonitis, gastrointestinal perforation, appendicitis, and cholecystitis are the main diseases of inflammatory adhesions. It has been reported that about 90% of abdominal surgeries have adhesions, and more than 40% will cause adhesive bowel obstruction. The reason for this is that clamping, traction, intraoperative electrodesiccation, heat production by electrocoagulation, tissue ischemia and prolonged exposure, and wiping with gauze (especially with dry gauze) during abdominal surgery can cause varying degrees of damage to the peritoneum and plasma membrane, especially the surgically separated trauma. Common intraperitoneal foreign bodies include talcum powder on the surgeon’s rubber gloves, sutured silk, drainage and caulking or leftover gauze; in addition intraperitoneal injection of chemotherapeutic drugs (such as carboplatin) can also trigger adhesions. In recent years, laparoscopic surgical techniques have been developed that can theoretically reduce adhesions. However, some scholars believe that the procedure does not significantly reduce the occurrence of adhesions because laparoscopic surgery mostly uses electrocoagulation and electrodesiccation, and heat production can increase tissue exudation; the separated trauma in the abdominal cavity is almost the same as that in open surgery; also, for example, in common laparoscopic cholecystectomy, the spilled bile is not easily isolated when the gallbladder is divided and broken, and the leaked stone debris can be easily left in the abdominal cavity as a foreign body, and all these factors can lead to adhesions. Intra-abdominal adhesions are abnormal adhesions between the mural peritoneum and the visceral peritoneum, and between the visceral peritoneum and the visceral peritoneum. Although the exact mechanism by which adhesions occur is not fully understood, it is well established that adhesions are a normal response to the physiological function of the peritoneum itself. It is also said that “without adhesions there is no healing”. In addition to lubrication, absorption and exudation, the defensive and reparative functions of the peritoneum are intrinsic to the formation of adhesions. When the peritoneum is stimulated biologically, physically or chemically, it is damaged locally to varying degrees and an acute inflammatory response occurs, leaking large amounts of phagocytosis, electrolytes, non-protein nitrogen and exudate containing fibrinogen. These exudates are concentrated on and near the surface of the irritated tissues and organs, and within a few hours fibrin coagulates and covers the damaged peritoneal surface and its vicinity, forming loose adhesions. Within 24 to 48 hours, the trabecular surface has cellular proliferation based on the inflammatory response, with the appearance of fibroblasts of different shapes and the gradual formation of collagen. At the same time, neutrophils and macrophages produce fibrinolytic activating factors, which contribute to fibrinolysis and absorption. These two processes interact with each other and reach a relative balance. When the exudate increases and the fibroblasts and the formed collagen cannot be completely lysed and absorbed, they are retained locally, connecting the wound to the surrounding tissue and forming adhesions. The majority of intra-abdominal adhesions do not present with specific clinical manifestations, and a small percentage may present with varying degrees of abdominal pain. When the adhesions make the intestinal tube into a mass, acute angle, twist or form an internal hernia under the adhesion band, as well as the gastrointestinal dysfunction caused by various reasons and the abnormal peristaltic movement of the intestinal tube, which affects the operation of intestinal contents to the distal side, adhesional intestinal obstruction is formed. Prevention Prevention of adhesions is the key to solve adhesive intestinal obstruction. Diseases causing peritonitis, such as tuberculous peritonitis and peritonitis after gastrointestinal perforation, should be actively prevented and thoroughly treated for inflammation of the peritoneal cavity. With the improvement of medical treatment, the incidence of tuberculous peritonitis and peptic ulcer perforation has decreased significantly, and the adhesive intestinal obstruction caused by these inflammatory diseases has been greatly reduced. Since abdominal surgery is the main cause of adhesive intestinal obstruction, active preventive measures should be taken during surgery. Surgeons should understand the causes and pathological mechanisms of adhesive bowel obstruction, fully recognize the potential dangers of adhesions, and avoid or reduce unnecessary surgical invasion. Wash the talcum powder from gloves before doing surgery, make appropriate incision sites and sizes, operate gently, avoid excessive traction, minimize damage to the intestinal canal, visceral plasma membrane and peritoneum; repair the peritoneal defect as much as possible, if the defect is too large, cover it with omentum and isolate the intestinal canal from the peritoneal defect; do not expose the intestinal canal and other tissues for a long time during surgery, and if the intestinal canal is moved out of the abdominal cavity, use 0.9% sodium chloride solution Do not block the blood vessels or clamp the intestinal tube for a long time, and avoid ligating large pieces to avoid affecting the blood supply; use less irritating sutures as much as possible, and the retained thread should not be too long; pay attention to aseptic operation during surgery to avoid contamination of the peritoneal cavity by spillage of gastrointestinal contents, and for patients with gastrointestinal perforation, the gastrointestinal contents have been spilled, and the peritoneal cavity should be thoroughly cleaned during surgery to reduce infection; abdominal drainage should preferably use less irritating It is best to use less irritating materials, place the site appropriately, avoid contact with the intestinal tube as far as possible, and the drainage material located in the middle and upper abdomen can be separated from the intestinal tube by the omentum. Do not leave gauze and other foreign bodies behind when closing the abdomen. Encourage the patient to get out of bed early after surgery so that the gastrointestinal motility can be restored as soon as possible. If the abdominal distension and poor intestinal peristalsis after surgery, Neostigmine or traditional Chinese medicine (Da Cheng Qi Tang, etc.) can be applied according to the situation. Most of the intra-abdominal adhesions do not lead to intestinal obstruction. The occurrence of obstruction often has certain causative factors, which must be brought to the attention of patients: 1. Regular diet, avoid overeating, and prevent a large amount of food from entering the proximal intestinal canal that has been affected by adhesions; 2. The above matters are especially important for patients who have already had intestinal obstruction. In addition, many studies have been made on the prevention of adhesive intestinal obstruction. Anticoagulants such as heparin or bicoumarin have been injected into the abdominal cavity to reduce fibrin agglutination and precipitation of fibrin after intra-abdominal bleeding and to facilitate absorption, but the results are not very satisfactory. Removal of the formed fibrin is also a method to reduce adhesions, such as the application of hyaluronidase, streptokinase, etc., but the results are also poor. Attempts have also been made to use hormonal drugs, such as hydrocortisone, to inhibit fibroblast viability, which is rarely used because the effect is not very significant and has some adverse effects. Separating the intestinal canal and peritoneum with chemical bioabsorbable membranes is a more promising method, such as sodium hyaluronate or sodium hyaluronate phosphate buffer, dextran, polyglycopyrrolidone and carboxymethylcellulose, etc. They are applied to the surface of the intestinal canal or viscera near the surgical site and to the peritoneum (especially the peritoneum at the incision), which can separate the intestine from the intestine and the intestine from the peritoneum and reduce adhesions. In addition sodium hyaluronate also inhibits bleeding and exudation and stimulates the growth and differentiation of mesothelial cells, thus improving the endogenous repair process. The use of a solution containing urea-based hydantoin, injected 250 mL before closing the abdomen, reduces and abates collagen exudation, prevents massive proliferation of fibroblasts, reduces intestinal edema, and allows rapid repair of the peritoneal epithelium. Despite the many reports above, there is still no reliable preventive drug recognized by the surgical community. Treatment The principles of treatment for adhesive intestinal obstruction are determined according to the cause, location, and degree of obstruction. If there is no manifestation of intestinal strangulation, non-surgical treatment should be used first. As with the general treatment of intestinal obstruction, effective gastrointestinal decompression is a very important measure. For lower obstruction, the commonly used gastric tube is shorter, and the nasal small intestine catheter (i.e. M-A tube) can be inserted into the proximal end of small intestine obstruction for decompression; using paraffin oil or traditional Chinese medicine (Si Mo Tang) is also often effective. The non-surgical treatment should be accompanied by good preoperative preparation, close observation of changes in the condition, and timely surgery if the treatment is ineffective or if intestinal strangulation is suspected. Surgery can mostly solve the obstruction, but there are more complications than non-surgical ones, and a few patients die due to complications. For limited adhesions or adhesion bands, the obstruction can be lifted by sharply separating them; if it is difficult to separate intestinal adhesions, resection of intestinal segments and intestinal anastomosis are feasible; if separation is difficult and resection is not possible, distal/proximal intestinal loops of obstruction can be found and lateral anastomosis of distal and proximal intestinal loops can be performed closer to the obstruction. For patients with heavy adhesions, recurrent obstruction, and repeated adhesion release surgery, it is necessary to perform an additional procedure to fix the small bowel alignment after releasing the adhesions and relieving the obstruction. In recent years, laparoscopic techniques have been used for the treatment of adhesive intestinal obstruction, i.e., laparoscopic dissection of the obstructing adhesions, which is suitable for patients with local adhesions and mild obstruction. Laparoscopy requires the judgment and operation of a physician with extensive experience. If laparoscopic surgery is difficult, the patient should be immediately referred for open surgery. Adhesions caused by tuberculous peritonitis are often extensive, firm, and not easily separated, and reluctant separation is not only prone to re-adhesion but also easy to complicate intestinal fistulae, most of which should be treated non-operatively, and then explored if strangulation is possible. Whether surgical or non-surgical treatment, the condition should be closely observed, blood volume should be replenished, antibiotics should be used at an early stage, blood or plasma transfusion may be appropriate for serious patients, water and electrolyte disorders and acid-base imbalance should be corrected, and nutritional support should be given. At present, there are still many problems of adhesive intestinal obstruction that remain to be solved and need to be further studied and explored.