Extraintestinal fistula

　　Caused by injuries from trauma, surgical injury, severe abdominal infection, chronic intestinal inflammation, and tumors, etc. Generally, after abdominal surgery trauma or infection, abdominal pain, distension, and fever may occur first, followed by localized or diffuse peritonitis, abdominal abscess signs. Later, the abscess may break through the abdominal wall incision or drainage orifice, forming a wound that continuously discharges pus, digestive fluid, or gas. In severe cases, there may be a labial fistula with inverted intestinal mucosa at the external orifice. Smaller intestinal fistulas may manifest as chronic infectious sinus tracts that intermittently discharge a small amount of intestinal contents or gas. Due to the long-term immersion or corrosion of the skin around the fistula by the discharged digestive fluid, ulcers and bleeding often occur. Patients may also have different degrees of water, electrolyte, and acid-base imbalance, as well as hypoproteinemia, and other internal environment imbalance, such as dehydration, edema, and weight loss. This can often lead to interspaces abscesses between the intestinal loops and abscesses around the fistula, resulting in fever and elevated blood count symptoms of infection. In severe cases, sepsis may occur, which may ultimately lead to multi-organ dysfunction.

　　Complications such as septic shock, massive gastrointestinal bleeding, respiratory failure, jaundice, acute respiratory distress syndrome, and coma may occur. When intestinal fistula is accompanied by severe peritoneal infection, there is often gram-negative bacillary sepsis and multi-organ dysfunction, which may lead to septic shock, massive gastrointestinal bleeding, jaundice, acute respiratory distress syndrome, and coma. It is necessary to strengthen monitoring and provide timely treatment. Strict monitoring of heart and lung function and blood electrolytes should be conducted. Timely treatment should be provided for complications such as septic shock, massive gastrointestinal bleeding, and respiratory failure.

　　1. Gastrointestinal contents may leak out through the body surface wound (i.e., fistula), and the fistula may not heal for a long time.

　　2. Early symptoms may include peritonitis or abdominal abscess, such as fever, abdominal distension, or localized tenderness, rebound pain, etc.

　　3. Systemically, dehydration, acidosis, and malnutrition may occur.

　　4. Local skin around the fistula may develop erosion and infection.

　　1. Prevent the occurrence of various acute and chronic peritoneal inflammation.

　　2. Master the timing of surgery and perform timely and accurate surgical treatment for diseases such as gastric perforation, appendicitis, and intestinal obstruction.

　　3. Correctly suture the intestinal wall during surgery to avoid injury to the intestinal tract and its blood supply.

　　4. Avoid the occurrence of intra-abdominal abscesses.

　　(1) Take a semi-recumbent position when treating peritonitis.

　　(2) Use effective antibiotics first.

　　(3) Ensure adequate aspiration or thorough flushing of the subdiaphragmatic area, peritoneal cavity, and pelvic space to remove any leaked fluid or pus.

　　(4) Place the drain appropriately.

　　5. Reduce the occurrence of adhesive intestinal obstruction.

　　(1) Timely and correct treatment of peritoneal inflammation.

　　(2) Hemostasis should be thorough during abdominal surgery to prevent the formation of hematomas.

　　(3) Minimize the time that the contents of the intestines are exposed to the peritoneal cavity outside and the time that gauze dressings cover the contact with the injured peritoneum.

　　(4) Wash talcum powder from gloves to avoid foreign bodies entering the peritoneal cavity.

　　(5) Avoid tearing or defects in the peritoneum.

　　(6) Minimize tissue ligation.

　　(7) Proper placement of peritoneal drainage items.

　　Examinations that should be done for gastrointestinal extraluminal fistulas include: ultrasonography of gastrointestinal diseases, gastrointestinal CT examination, and abdominal plain film.

　　1. The examination protocol for general patients is mainly limited to examination frames.

　　2. For patients with peritonitis, unknown etiology, or suspected gastrointestinal malignant tumors, the examination protocol may include examination frames 'A', 'B', or 'C'.

　　For patients with high-flow fistulas who cannot recover gastrointestinal intake, total parenteral nutrition can be administered via deep venous catheter, with 167-209 kJ (40-50 kcal) of calories provided per kilogram of body weight per day, and 0.2-0.3 grams of nitrogen per kilogram (equivalent to 1.3-1.95 grams of protein per kilogram). For some high-position fistulas, a nasogastric tube can be inserted into the distal part of the intestinal tract of the fistula or an enterostomy can be performed, or a tube can be inserted through the fistula orifice and sent to the distal part of the fistula for tube feeding or elemental diet administration until oral intake is possible.

　　1. Early and adequate drainage to control peritoneal infection

　　In patients with abdominal wall trauma and peritoneal signs after gastrointestinal surgery, laparotomy should be performed when suspected of having a fistula. When gastrointestinal fistula is confirmed, the peritoneal cavity should be thoroughly flushed, a drain should be placed to ensure adequate drainage, and multiple drains or double-lumen tubes with continuous negative pressure suction may be necessary if required. Antibiotics should be selected based on the results of bacterial culture to control infection.

　　2. Maintain Nutrition

　　For patients with high-flow fistula, when gastrointestinal intake cannot be restored, total parenteral nutrition treatment can be performed through deep venous catheterization, with an energy supply of 167-209 KJ (40-50 kcal) per kilogram per day and a nitrogen supply of 0.2-0.3 grams per kilogram (equivalent to 1.3-1.95 grams of protein per kilogram). For some high-level fistula, the nasogastric tube can be inserted into the distal intestinal tract of the fistula or enterostomy can be performed, or a tube can be inserted through the fistula orifice and sent to the distal side of the fistula for enteral feeding or to provide elemental diet until oral intake is possible.

　　3. Local Treatment of Fistula Orifice

　　①Tubular fistula, after 2-4 weeks of sufficient drainage, peritoneal infection can be controlled and the excretion volume of gastrointestinal contents can gradually decrease, then the drainage tube can be gradually removed until the fistula heals naturally.

　　②Large fistula orifice, short fistula tube, and lip-shaped fistula can be blocked with silicone sheet, and after successful internal blocking, the patient's diet can often be restored and the patient's nutritional status can be improved to facilitate early surgical treatment.

　　③If the skin around the fistula orifice is eroded, zinc oxide ointment can be applied to protect the skin to prevent the contents of the gastrointestinal tract from eroding the skin.

　　4. Surgical Treatment

　　①Indications: ①The fistula does not heal for a long time after the above treatment or the fistula tube has been epithelialized. ②Lip-shaped fistula. ③Small intestinal fistula with excretion volume > 5000ml/day after the above treatment. ④Obstruction of the distal intestinal tract of the fistula.

　　②Surgical timing: ①Peritoneal infection has been localized or controlled. ②Good general nutritional status. ③Generally, fistula lasts for more than 3 months. However, for small intestinal fistula with large excretion volume, surgery should be performed as soon as possible after the inflammation is controlled and nutritional status is improved.

　　③Surgical methods: The commonly used surgical methods at present include: ①Intestinal resection and anastomosis. Suitable for early small intestinal fistula and patients with mild peritoneal infection. ②Intestinal fistula bypass surgery. Bypass the intestinal segment with the fistula, anastomose the distal and proximal ends of the small intestine, and restore the continuity of the intestine. Suitable for small and large intestinal fistula. ③Vascular pedicle intestinal seromuscular flap repair: Suitable for repairing fistulae that are difficult to resect, such as duodenal fistula.

　　5. Prevention and Treatment of Complications

　　Strictly monitor heart, lung function, and blood electrolytes. Timely treatment should be provided for complications such as infectious shock, massive gastrointestinal bleeding, and respiratory failure.