Intestinal fistula

Introduction to intestinal fistula Intestinal fistula (fistulaofintestine) refers to a series of pathophysiological changes such as infection, fluid loss, malnutrition and organ dysfunction. Intestinal fistula can be divided into two types: inner and outer. basic knowledge The proportion of illness: 0.005% Susceptible people: no specific people Mode of infection: non-infectious Complications: malnutrition, edema, metabolic acidosis

Cause of intestinal fistula

Causes:

Common causes of intestinal fistula include surgery, trauma, abdominal infection, malignant tumor, radiation damage, chemotherapy, intestinal inflammation and infectious diseases. Clinically, intestinal fistula mainly occurs after abdominal surgery, which is a kind of postoperative operation. Serious complications, the main cause is postoperative abdominal infection, anastomotic rupture, poor intestinal blood flow caused by anastomotic leakage, intestinal inflammation, tuberculosis, intestinal diverticulitis, malignant tumor and traumatic infection, abdominal inflammation, abscess It can directly penetrate the intestinal wall and cause intestinal fistula. Some are complications of inflammatory bowel disease itself, such as internal hemorrhoids or external hemorrhoids caused by Crohn's disease. According to clinical data analysis, intestinal fistula is secondary to abdominal abscess, infection and infection. Intestinal fistula is the most common after surgery, intestinal fistula is common in malignant tumors, radiation therapy and chemotherapy can also cause intestinal fistula, relatively rare.

Pathogenesis:

Pathological change staging

The occurrence and development of typical intestinal fistula generally goes through 4 stages, and the following pathological changes appear successively:

(1) peritonitis: mainly occurs within 1 week after trauma or surgery. As the contents of the intestine leak through the defect of the intestinal wall, it stimulates the tissue around the leak and causes peritoneal inflammation. The severity depends on the location of the fistula. Size, leakage properties and quantity vary, high, high flow jejunum sputum, leakage fluid contains a lot of bile, pancreatic juice, has a strong digestion, corrosive effect, and large flow, often forming acute diffuse peritonitis, mouthwash Small, low-flow intestinal fistula can form localized peritonitis.

(2) localized abscess: more than 7 to 10 days after the onset of intestinal fistula, due to acute intestinal fistula caused by abdominal inflammation, intraperitoneal cellulose exudation, drainage, omentum wrapping, intestinal leakage surrounding organs Adhesive and so on, the leakage is limited, and the package forms a localized abscess.

(3) fistula formation period: the above abscess can be broken without artificial drainage in time, so that the abscess can lead to the surface or surrounding organs, from the intestine wall to the abdominal wall or other organs, forming a fixed Abnormal pathway, pus and intestinal fluid flow out through this channel.

(4) fistula closure period: With the improvement of systemic conditions and effective treatment, the contents of the fistula are circulated smoothly, the surrounding tissue inflammation subsides and the fibrous tissue proliferates, and the fistula will be finally filled with granulation tissue and form fibrous scars to heal.

2. Pathophysiological changes

After the appearance of intestinal fistula, in addition to the pathophysiological changes caused by the original disease, intestinal fistula itself will also cause a series of unique pathophysiological changes, including: water and electrolytes and acid-base disorders, malnutrition, the corrosive effects of digestive enzymes, infection And organ dysfunction, etc., according to the location, size, flow rate of the mouth and the original disease, the impact on the body is also different, the systemic pathophysiological changes caused by intestinal fistula with small mouth, low position and low flow rate Small; high-level, high-flow sputum caused by obvious pathophysiological changes, and even multiple organ failure (MOF), leading to death.

(1) Water and electrolytes and acid-base disorders: Intestinal fistulas are classified into high-flow enthalpy and low-flow enthalpy according to the amount of their outflow. The amount of digestive fluid loss depends on the location of the intestinal fistula. The duodenum and jejunum lose a large amount of intestinal fluid, which is also called high intestinal fistula. The loss of colon and ileal intestinal fluid is called low intestinal fistula, and a large amount of intestinal fluid loss causes dehydration. Electrolytes and acid-base disorders, even endangering the lives of patients.

(2) Malnutrition: Loss of intestinal fluid, loss of nutrients and digestive enzymes in intestinal fluid, obstacles to digestion and absorption, and infection and other factors have aggravated malnutrition, and the consequences are the same as short bowel syndrome.

(3) Corrosion of digestive enzymes: Corrosion of the skin by the intestinal juice can cause skin erosion, ulceration and even necrosis. The digestive juice accumulates in the abdominal cavity or fistula, which may corrode other organs, and may also cause a lot of bleeding due to corrosion of blood vessels, and the wound is difficult to heal.

(4) Infection: Once the intestinal fistula occurs, the abscess is formed in the abdominal cavity due to poor drainage. The bacteria in the intestinal cavity contaminate the surrounding tissue and cause infection, and the infection is difficult to be restricted due to the corrosive action of digestive enzymes, such as intestinal fistula and biliary tract. The bladder is connected to cause infection of the corresponding organs, and even sepsis.

Water and electrolytes and acid-base balance disorders, malnutrition and infection are the three basic pathophysiological changes in patients with intestinal fistula, especially malnutrition and infection in patients with intestinal fistula are often more serious, and cause each other, forming a vicious circle, can cause pus Toxemia and multiple organ dysfunction syndrome (MODS), and finally MOF and death.

Intestinal fistula prevention

75% to 85% of intestinal fistula is caused by surgery, so some complications during prevention are key.

1. Pathological intestinal fistula was reviewed 3 months and half a year after discharge, and the primary disease (intestinal tuberculosis, Crohn's disease, etc.) was examined. Intestinal fistula caused by trauma should be treated in the hospital when there is abdominal symptoms.

2, to prevent the occurrence of various acute and chronic intra-abdominal inflammation.

3, master the timing of surgery, timely and accurate surgical treatment of gastric perforation, appendicitis, intestinal obstruction and other diseases.

4, intraoperative intestinal wall suture should be correct, to avoid damage to the intestine and its blood.

5, to avoid the occurrence of abdominal abscess.

1 Take a semi-recumbent position when treating peritonitis.

2 Use effective antibiotics first.

3 Fully attract or thoroughly flush the leakage or pus stored in the infraorbital area, abdominal cavity, pelvic cavity.

4 Place the drain tube properly.

6, reduce the incidence of adhesive intestinal obstruction.

1 timely and correct treatment of abdominal inflammation.

2 hemostasis should be completely stopped during abdominal surgery to prevent the formation of hematoma.

3 Try to shorten the time when the contents of the intestines are exposed to the abdominal cavity and the time when the gauze dressing covers the contact with the damaged peritoneum.

4 Wash the talcum powder on the gloves to prevent foreign matter from entering the abdominal cavity.

5 to avoid peritoneal tears, defects.

6 tissue ligation should be less.

7 Place the abdominal drainage properly.

Intestinal fistula complications Complications malnutrition edema metabolic acidosis

1, most patients with intestinal fistula have different degrees of malnutrition, may have hypoproteinemia, edema, weight loss, low potassium, low sodium, metabolic acidosis and so on.

2, further development of intestinal fistula can also occur diffuse peritonitis, sepsis, etc., there may be some diseases associated with sputum, such as digestive tract tumors, intestinal adhesions, inflammatory bowel disease, severe pancreatitis and multiple trauma.

Symptoms of intestinal fistula Common symptoms Abdominal pain Abdominal wound outflow Fecal sample Intraperitoneal infection Hypoproteinemia Bloating High fever Diarrhea Intestinal adhesions weight loss

The clinical manifestations of intestinal fistula are complex, and its severity is affected by many factors, including the type and cause of intestinal fistula, the physical condition of the patient, and the different stages of intestinal fistula. There is no obvious symptom or physiological disorder in the intestinal fistula. Intestinal fistula is usually characterized by localized or diffuse peritonitis. Patients may have fever, abdominal distension, abdominal pain, local abdominal wall tenderness and rebound pain. After surgery, patients are sometimes indistinguishable from the symptoms and signs of the original disease. Clinicians The patient complained of bloating, lack of adequate attention to exhaustion and defecation, and this was attributed to postoperative intestinal peristalsis, intestinal adhesions, etc., often losing the early diagnosis of intestinal fistula.

After the fistula is formed and the intestinal fluid overflows, the main manifestations are: the formation of the fistula and leakage of intestinal contents, infection, malnutrition, water and electrolyte and acid-base balance disorders and multiple organ dysfunction.

1. The formation of the fistula and the leakage of intestinal contents: The characteristic manifestation of extraintestinal fistula is that one or more fistulas may appear on the abdominal wall, and intestinal fluid, bile, gas, feces or food may flow out, and lip-shaped fistula may be observed on the wound surface. The eversion of the intestinal mucosa, and even the ruptured intestine, the skin around the mouth is red and swollen, and due to the action of the digestive juice, large skin or abdominal wall defects may occur, duodenal fistula and high jejunum fistula, and the outflow may be large. Up to 4000 ~ 5000ml / d, containing a large amount of bile and pancreatic juice, foods that are eaten by mouth are quickly discharged from the mouth of the mouth; lower intestinal fistula, the amount of outflow is still more, the intestinal juice is thicker, mainly for partially digested chyme; colon generally has a small amount of effluent, semi-formed feces, skin erosion around the mouth of the mouth is light, intestinal sputum can be expressed as varying degrees of diarrhea, ineffective use of antidiarrheal agents, intestinal and ureter, bladder or uterus, It can occur that the contents of the intestine are discharged with the urine or from the vagina, or the urine is discharged with the stool.

2, infection: infection is an important factor in the occurrence and development of intestinal fistula, is also one of the main clinical manifestations, abdominal infection, especially abdominal abscess can cause intestinal fistula, early intestinal fluid leakage will cause different degrees of abdominal infection, abdominal abscess If the disease progresses further, there may be clinical manifestations such as diffuse peritonitis and sepsis.

3, malnutrition: due to leakage of intestinal contents, especially digestive juice, resulting in digestion and absorption disorders, coupled with infection, reduced consumption and the impact of the primary disease, intestinal fistula patients mostly have varying degrees of malnutrition, may have hypoproteinemia , edema, weight loss and other corresponding clinical manifestations.

4, water and electrolytes and acid-base balance disorder: depending on the type of intestinal fistula, flow rate, varying degrees of internal homeostasis, can be diverse, common low potassium, low sodium, metabolic acidosis.

5, multiple organ dysfunction: late intestinal tract, the disease can not be controlled, there may be multiple organ dysfunction, more likely to appear gastrointestinal bleeding, liver damage, etc. In addition, intestinal fistula patients may also have some associated with sputum Diseases, such as digestive tract tumors, intestinal adhesions, inflammatory bowel disease, severe pancreatitis, and multiple trauma, have corresponding clinical manifestations.

After the occurrence of duodenal fistula, the patient often presents with sudden persistent abdominal pain, which is most obvious in the right upper abdomen. Local abdominal muscle tension, tenderness, rebound tenderness, may be accompanied by high fever, pulse rate, and elevated white blood cells. Perforation of duodenal ulcer, duodenal stump anastomotic fistula after gastrectomy, blind obstruction, duodenal diverticulum and endoscopic examination, etc., the severity of the symptoms is related to the amount of leakage, The hole is small, the leakage is only a small amount of mucus and duodenal juice, the symptoms are lighter and heal faster; if the mouth is larger, a large amount of water-like bile leaks out, and the skin near the wound is quickly eroded and massively digested. The loss of liquid, water, electrolyte imbalance, and even death.

The jejunum ileum often has diarrhea, the external hemorrhoids have obvious intestinal fluid spillage, the skin of the mouth is red and swollen, erosive, painful, and often have abdominal infections, long-term external hemorrhoids, large amounts of intestinal fluid loss, varying degrees of malnutrition, when the intestines When the cavity communicates with other organs, such as the urinary system, the infection symptoms of the corresponding organs often occur. The distal part of the intestinal fistula often has partial or complete obstruction. The persistent infection may cause malnutrition and rapid weight loss. decline.

Examination of intestinal fistula

Tracheal angiography: through oral dye or through a catheter inserted into the fistula or directly into the fistula with a syringe, sputum angiography, oral dilution of bone charcoal powder or methylene blue, regular observation of the fistula, recording bone charcoal powder or methylene blue discharge The amount and time, if the dye is discharged through the wound, the diagnosis is clear; according to the discharge time, the location of the fistula can be roughly estimated; according to the amount of discharge, the size of the fistula can be estimated initially, and the fistula angiography can help to identify the site of the fistula. The size, the length of the fistula, the length of the fistula, and the extent of the abscess can also be used to understand the condition of some of the intestinal fistulas associated with the intestinal fistula.

1, abdominal plain film: through the abdomen, lying flat to check for intestinal obstruction, whether there is abdominal cavity occupying lesions.

2, B-ultrasound: can check the presence or absence of abscess in the abdominal cavity and its distribution, to understand whether there is chest and ascites, with or without abdominal cavity organ mass lesions, etc., if necessary, B-ultrasound guided percutaneous drainage.

3, digestive tract angiography: including oral contrast agent for total gastrointestinal angiography and transabdominal wall digestive tract angiography, is an effective means of diagnosis of intestinal fistula, often can be clear whether there are intestinal fistula, the location and number of intestinal fistula, fistula The size, the distance between the mouth and the skin, whether the mouth is accompanied by the drainage of the abscess and the fistula, and also the clear mouth, the proximal bowel is unobstructed, if it is a lip, it is clear at the proximal end of the fistula After the condition of the intestine, a contrast agent can also be injected into the distal intestine through the fistula for examination.

For gastrointestinal tract examination of patients with intestinal fistula, attention should be paid to the choice of contrast agent. It is generally not suitable to use sputum, because sputum can not be absorbed and difficult to dissolve, and it will cause the sputum to remain in the abdominal cavity and fistula, forming foreign bodies and affecting intestinal fistula. The self-healing; the inflammatory reaction caused by the leakage of the expectorant into the abdominal cavity or the thoracic cavity is also severe. Generally, 60% of the diatrizoate is used for the early intestinal fistula, and 60% of the diatrizoate 60-100ml is directly orally administered. Or through the stomach tube injection, can clearly show the intestinal fistula, the intestinal cavity and leakage into the abdominal cavity of the diatrizoate can be quickly absorbed, do not need to further dilute 60% of the diatrizoate, otherwise the contrast of contrast Poor, it is difficult to clear the intestinal fistula and its accompanying situation, dynamic observation of gastrointestinal motility and contrast agent distribution during angiography, pay attention to the leakage of the contrast agent, the amount and speed of leakage, with or without branching fork and abscess.

4, CT: CT is an ideal method for clinical diagnosis of intestinal fistula and its associated abdominal and pelvic abscess, especially through oral gastrointestinal contrast agent, CT scan, not only can clear the intestinal patency and fistula, but also assist in surgery Pre-evaluation, help determine the timing of surgery, inflammatory adhesions, obvious bowel CT examination showed intestinal adhesions into a mass, intestinal wall thickening and intestinal effusion, at this time, if extensive adhesion separation, not only can not completely separate adhesions, but also It will cause more secondary damage to the intestines, resulting in more paralysis and complete failure of the operation.

5, other examinations: for small intestine gallbladder fistula, small intestine bladder fistula, etc. should be performed bile duct, urography and other examinations.

Diagnosis of intestinal fistula

Diagnostic criteria

According to clinical manifestations and medical history and related examinations, there is no difficulty in the diagnosis of intestinal fistula. However, in order to implement correct treatment, the following important issues need to be clarified in the diagnosis of intestinal fistula:

1. The location and number of intestinal fistulas, that is, whether it is a high intestinal fistula or a low intestinal fistula, is a single wart or a multiple warts.

2, the movement of the fistula, such as the shape and length of the fistula, whether there is a abscess, whether it is connected with other organs.

3, the patency of the intestines, is the end of the sputum or lateral sputum, the distal end of the sputum with or without obstruction.

4, the cause of intestinal fistula, benign or malignant.

5, with or without abdominal abscess and other complications, drainage of the fistula.

6, the patient's nutritional status and vital organ function, whether there is water, electrolytes and acid-base balance disorders.

In order to clarify the above situation, the diagnosis of intestinal fistula generally requires a more comprehensive examination, including laboratory examination, imaging examination, especially gastrointestinal and fistula or sinus angiography.

Differential diagnosis

1. Digestive tract perforation

Sudden severe abdominal pain, abdominal fluoroscopy can be found in the underarm free gas, with signs of peritonitis.

2, intestinal inflammatory disease

Including bacterial dysentery, ulcerative colitis, Crohn's disease, etc., these diseases can occur abdominal pain, diarrhea, mucus and blood, colonoscopy can be identified.

3, colon cancer

The age of the two diseases is similar, even can exist at the same time, the clinical manifestations are partially overlapped, and complications such as intestinal obstruction, hemorrhage, perforation and fistula formation can occur. Barium enema helps to identify, irregular mucosa, intestinal filling defect Radiological signs of colon cancer, colonoscopy and mucosal biopsy have diagnostic significance for colon cancer.

4. Colonic Crohn's disease

Colonic Crohn's disease has abdominal pain, fever, elevated peripheral blood leukocytes, abdominal tenderness, abdominal mass, etc. The formation of fistula is characteristic. These symptoms and signs are similar to diverticulitis. Endoscopic and X-ray examinations can find paving stones. Mucosal changes, deep ulcers, and a "jumping" distribution of lesions are helpful for identification. Endoscopic mucosal biopsy has diagnostic value if non-caseous granuloma is found.

5, ulcerative colitis

Can be expressed as fever, abdominal pain, bloody stools, peripheral blood leukocytosis, colonic mucosa showed diffuse inflammation, congestion, edema, with the development of the disease, may appear erosion, ulcers, pseudopolyps, residual mucosal atrophy between ulcers, late There is a narrowing of the intestinal lumen, the disappearance of the colonic bag, etc., and the changes in goblet cells and crypt abscess can be seen in the examination.

6. Ischemic colitis

Ischemic colitis occurs in the elderly and can occur simultaneously with colonic diverticulosis. The clinical manifestations are mostly black stools after severe abdominal pain. The characteristics of thumbprint enema can be used to diagnose ischemic colitis. Colonoscopy is helpful in diagnosing the disease.

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