Vesicosigmoid fistula

　　Vesicosigmoid fistula has a low clinical incidence, with the incidence rate of intestinal-vesical fistula reported in foreign literature being about 0.02%-0.03%, and there are only scattered reports in China. Vesicosigmoid fistula mostly occurs in male patients. The causes of vesicosigmoid fistula are many, summarized into five categories: congenital, traumatic, tumor, inflammatory, and other factors. Among them, trauma is the main cause.

　　After repair or resection anastomosis for colonic injury, inflammation, or tumor, leakage at the anastomosis site may occur, which often occurs 4-5 days after surgery. After the pain in the abdomen decreases after surgery, persistent pain increases, often accompanied by sepsis, such as fever, abdominal tenderness, rebound tenderness, and increased muscle tension. At this time, it should be considered first for abdominal infection, or there is a possibility of forming an intestinal fistula.

　　Vesicosigmoid fistula, as the name implies, refers to an abnormal passage formed between the bladder and the sigmoid colon. Vesicosigmoid fistula causes great harm to the human body, and the feces inside the sigmoid colon often pass through the fistula into the bladder, causing urinary system infection.

　　When vesicosigmoid fistula causes abdominal infection, it may be accompanied by severe peritonitis; the loss of intestinal contents through the fistula can lead to the loss of water and electrolytes and malnutrition and other complications, as well as cystitis caused by bladder infection leading to urethritis, pyelonephritis, and purulent nephritis.

　　Ureterosigmoid fistula is a very rare disease with few clinical cases. Fecal and urinary incontinence are the main symptoms of this case, and also the main reason why patients come to seek medical attention. The clinical manifestations of fecal and urinary incontinence differ due to different causes. Urinary incontinence is more common in patients with diverticulitis and Crohn's disease, while fecal incontinence is more common in patients with tumors, and may be accompanied by refractory diarrhea and gross hematuria. Fecal incontinence is not common, and may be due to the higher position of the sigmoid colon than the bladder, forming a pressure difference, where the pressure inside the sigmoid colon is higher than the pressure inside the bladder. However, if the sigmoid colon and bladder are lip-shaped adhered, and the fistula is large enough to eliminate the pressure difference, fecal incontinence symptoms may also occur.

　　Vesico-sigmoid colonic fistula is mostly caused by trauma, such as colon injury, inflammation, or tumor, etc., after colonic repair or intestinal resection and anastomosis. The anastomotic mouth splits and leaks fluid, which usually occurs 4 to 5 days after surgery. Therefore, to effectively prevent the occurrence of vesico-sigmoid colonic fistula, attention should be paid to the treatment of wounds during various surgical procedures of the intestines. At the same time, good living habits should be maintained, and attention should be paid to daily life:

　　1. Establish normal dietary habits.

　　2. Prevent and treat constipation and diarrhea.

　　3. Develop good defecation habits.

　　Locating the fistula position is the key to diagnosing sigmoid colon-vesical fistula. Cystoscopy is of great value in understanding the lesions within the bladder lumen and the position of the bladder fistula, with a diagnostic rate of about 67%. Feces floating in the bladder, local erythema-like changes of the mucosa, attached pus, and even the direct discovery of the fistula are visible. Bladder造影 and IUP examination are of little significance.

　　The diagnosis of intestinal fistula is mainly determined through barium enema and colonoscopy. Barium enema is difficult to enter the bladder due to the high compliance of the intestinal lumen, narrow fistula, and blockage of secretions from the fistula. Colonoscopy is to observe the fistula under direct vision. Due to redness, hyperplasia, erosion, and a large amount of exudate at the fistula site, it is difficult to directly observe the fistula. The positive rate of erosion, polyps, tumors, and diverticula is high.

　　Ultrasound and CT can comprehensively examine the bladder, sigmoid colon, and fistula, but CT is more accurate. Literature reports that the accuracy rate of CT diagnosis is 60% to 100%. The characteristic sign of CT diagnosis of vesico-intestinal fistula is the presence of gas shadows in the bladder, but the existence of urogenital gas-forming bacteria and iatrogenic gas must be excluded. In addition, CT can also determine the cause of the disease.

　　Patients with vesico-sigmoid colonic fistula require surgical treatment. Before surgery, patients should be given a high-protein, high-calorie, high-vitamin, low-fat, easily digestible, low-residue or residue-free diet to enhance their body's resistance and reduce feces. Three days before surgery, a residue-free liquid diet should be provided, and fasting should be avoided one day before surgery to reduce feces. Before surgery, a laxative should be used to thoroughly clean the intestines to clean the bacteria within the intestines and reduce the amount of intestinal bacteria. After surgery, patients should fast for 3 to 4 days, and after the intestinal peristalsis recovers (indicating that gas is溢出 from the stoma), they can start with a liquid diet. After about 10 days, soft food can be introduced, attention should be paid to dietary hygiene and matching, and sufficient fluid intake should be ensured to prevent constipation and diarrhea.

　　Reduce the intake of the following foods during meals:

　　① Foods that are easy to produce gas, such as dairy products, milk products, overly sweet foods, carbonated drinks, etc.;

　　② Foods that produce a strong odor in feces, such as meat, eggs, garlic, onions, etc.;

　　③ Foods that are easy to cause diarrhea, such as alcohol, spinach, celery, chives, etc.;

　　④ Foods that are easy to cause constipation, such as fried foods and nuts, should be avoided to prevent obstruction of the intestinal tract and stoma as well as inconvenience in daily life and work caused by frequent use of the ostomy bag.

　　The treatment of vesicocolonic fistula in Western medicine is based on different stages of treatment for patients with sigmoid colon vesicocolonic fistula:

　　First Stage (7-10 days after the fistula occurs)

　　The patient is in the unstable period of the fistula opening and the early stage of infection. Abdominal infection is severe, with local inflammation and edema. If surgical repair of the intestinal fistula opening often fails and can lead to the spread of infection; the patient should be fasting, with gastric and intestinal decompression, and parenteral nutrition should be given to correct the general condition; antibiotics should be given, and the abdominal infection focus should be thoroughly drained, and the intestinal contents should be completely drained out of the abdominal cavity (the wound should be cleared in time or a catheter should be inserted for drainage).

　　Second Stage (10-30 days)

　　After the first stage of treatment, the patient gradually recovers, and the fistula has become a 'controlled' fistula after drainage or treatment. Infection is still very serious or continuing to spread, so it is necessary to actively control infection and strengthen nutrition. Especially, total parenteral nutrition is a necessary means to provide calories and nitrogen sources.

　　Third Stage (1-3 months)

　　After 1 to 2 stages of treatment, the fistula openings with good effects have healed or stabilized. Since intestinal fistula has a low impact on nutrition, but when the fistula does not heal, it is necessary to understand the factors causing non-healing in a timely manner. Common causes include:

　　①There is an obstruction at the distal end of the fistula.

　　②The tissue of the fistula has been epithelialized.

　　③The colon mucosa has healed with the abdominal wall, making the fistula opening lip-shaped.

　　④There is a foreign body in the fistula opening.

　　⑤The abscess near the fistula opening is not draining well.

　　⑥Special infection or tumor exists.

　　During this period, the focus is to find the cause of fistula non-healing, control abdominal infection, especially interwall abscesses in the intestinal wall, and timely laparotomy and drainage of abscesses should be performed when highly suspected. Of course, when B-ultrasound can be used to confirm, puncture and aspiration of pus, injection of antibiotics, can be performed under its guidance to relieve concerns about widespread adhesions in the abdominal cavity during surgery and the risk of intestinal injury.

　　Fourth Stage

　　For patients with unhealed intestinal fistula, abdominal infection control, good local condition of the fistula opening, consider elective surgery to clear the cause of the disease and close the fistula. If there is a distant obstruction at the distal end of the fistula, it should be relieved before repairing the fistula opening; for simple lip-shaped fistula or tubular fistula, the fistula can be turned towards the intestinal lumen without excessive exploration of the abdominal cavity. Of course, when there is a special infection or tumor at the anastomosis site, the lesion should be excised and anastomosed.