Urothelial fistulas

Uroenteric fistula is a pathological communication between the urinary tract and the intestine.

Epidemiology

The incidence of new cases in patients with sigmoid diverticulosis in the United States reaches 2%. Specialized medical centers cite higher figures. Malignant neoplasms of the colon are accompanied by the formation of ureteral fistulas in 0.6% of cases.

At the same time, over the past decades, the number of patients with renal-intestinal and ureter-intestinal fistulas has significantly decreased, which is associated with early diagnosis and effective treatment of purulent-inflammatory diseases of the kidneys and urinary tract. According to V. S. Ryabinsky and V. N. Stepanov, only six (6.7%) of ninety observed patients with ureteral fistulas suffered from renal and ureter-intestinal fistulas. The remaining patients were diagnosed with vesicointestinal and urethrorectal fistulas. Ureteric fistulas are detected 3 times less often in women than in men, which can be explained by more frequent diseases and injuries of the large intestine and bladder in the latter.

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Causes ureteric fistulas

Uroenteric fistulas can be congenital and acquired. Congenital vesicoenteric fistulas are extremely rare. They usually occur between the rectum and the vesical triangle, sometimes combined with anal atresia. Acquired ureteric fistulas are most often detected. They are divided into post-traumatic and spontaneous (as a result of various pathological conditions). The causes of the former are considered to be simultaneous injuries to the urinary tract and intestines due to iatrogenic injuries, radiation therapy, and surgical interventions (trocar epicystostomy, TUR of the prostate and bladder neck, RPE).

Spontaneous ureteral fistulas usually form as a result of various inflammatory processes, neoplasms, perforation of the intestinal wall and bladder by foreign bodies. Renal-intestinal fistulas most often occur as a result of purulent-inflammatory, including specific, diseases of the kidney and perirenal tissue. Ureterointestinal fistulas are mainly iatrogenic in nature and form with combined damage to the ureter and intestine during operations on the abdominal organs and urinary tract. Thus, renal and ureteral-intestinal fistulas, as a rule, occur as a result of inflammatory diseases of the kidneys and urinary tract with secondary involvement of various parts of the intestine in the process, and vesicointestinal fistulas - as a result of primary diseases and injuries of the intestine, spreading to the bladder.

Diverticulosis and chronic colitis are the most common causes of enterovesical fistulas. These diseases lead to the formation of internal communications between the intestine and the bladder in 50-70% of patients. In 10% of cases, fistulas occur as a result of Crohn's disease, and they usually form between the bladder and the ileum. Less commonly, enterovesical fistulas are formed as a result of Meckel's diverticulum, appendicitis, urogenital coccidioidomycosis, and pelvic actinomycosis.

The second most important (20% of cases) cause of intestinal-vesical fistulas is malignant neoplasms (most often colorectal cancer). In case of bladder tumors, the formation of vesicointestinal fistulas is observed extremely rarely, which can be explained by the early diagnosis of the disease.

Remote radiotherapy or brachytherapy can lead to the formation of pathological communications between the intestine and the urinary tract even after several years. The occurrence of a fistula due to radiation damage and intestinal perforation with the formation of a pelvic abscess that broke through into the bladder has been described. There are many publications devoted to the formation of intestinal-vesical fistulas due to the presence of foreign bodies in the body. The latter can be in the intestine (bones, toothpicks, etc.), abdominal cavity (stones that got into it from the gallbladder during laparoscopic cholecystectomy). bladder (long-term catheterization of the organ). The cause of urethrorectal fistulas can be iatrogenic damage to the urethra and intestine during transurethral manipulations.

Symptoms ureteric fistulas

Complaints of patients with ureteral fistulas are usually caused by changes in the urinary system. In renal and ureteral-intestinal fistulas, against the background of urostasis, pain in the lumbar region, increased body temperature, and chills occur. Patients with vesicointestinal fistulas note discomfort or moderate pain in the lower abdomen, frequent painful urination, and tenesmus. The urine of patients acquires a foul odor. An increase in temperature is caused by acute pyelonephritis or the formation of an interintestinal abscess preceding the formation of a vesicointestinal fistula.

Specific symptoms of enterovesical fistula are absent in some cases, and the disease of ureteric fistula occurs under the guise of recurrent urinary tract infection. Fecaluria and pneumaturia may occur episodically, in connection with which special attention should be paid to collecting anamnesis. Pneumaturia is detected in 60% of patients, but it is not considered a specific sign of the disease. It is also observed in the presence of gas-forming microorganisms (clostridia), fungi in the bladder in patients with diabetes mellitus, after instrumental examination. Pneumaturia is more often detected in diverticulosis of the sigmoid colon or Crohn's disease than in intestinal neoplasms.

In urethrorectal fistulas, patients complain of pneumaturia, the release of intestinal gases from the external opening of the urethra outside the act of urination. Fecaluria is a pathognomonic symptom of urethrorectal fistulas, observed in 40% of patients. Very characteristic symptoms of urethrorectal fistula are the passage of small, shapeless fecal particles with urine. The contents are thrown back in most cases from the intestines into the bladder, and not vice versa. Patients rarely notice the presence of urine in the intestinal contents.

When strictures of the posterior urethra (its poor patency) are combined with a urethrorectal fistula, all or most of the urine may enter the rectum, causing patients to urinate through it, as happens after transplantation of the ureters into the sigmoid colon. In the case of renal and ureter-small intestine fistulas, admixtures of bile and pieces of food are detected in the urine.

Flatulence, diarrhea or constipation often occur. In some cases, blood is observed in the stool. The clinical picture largely depends on the disease that caused the fistula. This is why a renal-intestinal fistula manifests itself with symptoms of purulent pyelo- and paranephritis. The entry of purulent urine into the intestines may be accompanied by diarrhea, nausea and vomiting. When feces penetrate the kidney, urine mixed with bile, food particles, gases and feces may be released.

In the case of an external ureteral fistula, a cutaneous opening of the latter is detected. through which urine with an admixture of intestinal contents and gas is released; when palpating the abdomen in patients with diverticulosis and chronic colitis, pain is detected along the sigmoid colon. The formation of an interintestinal infiltrate and its abscessing are accompanied by symptoms of peritoneal irritation. A volumetric formation in the abdominal cavity can be determined, which is also characteristic of Crohn's disease and malignant neoplasms.

Forms

Based on location, ureteral fistulas are divided into:

• renal and intestinal;
• ureteric-intestinal;
• vesicointestinal;
• urethrorectal.

Depending on the communication through the cutaneous fistula with the external environment, a distinction is made between open and closed ureteral fistulas.

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Diagnostics ureteric fistulas

Urine tests reveal leukocytes, erythrocytes, bacteria and fecal admixture. A test for detecting charcoal (after oral administration) in urine sediment is recommended. Bacteriological analysis of urine usually reveals the growth of several types of microorganisms with a predominance of E. coli. Patients with cancer have anemia and an increase in ESR. Leukocytosis may be a consequence of a urinary tract infection, a sign of a developing abscess. A biochemical blood test is mandatory (determination of creatinine, electrolytes, etc.).

Instrumental diagnostics of ureteral fistulas

Ultrasound is not informative enough, so it has not become widely used in the diagnosis of ureteral fistulas.

In the case of an external ureteral fistula, fistulography can be performed, which notes the contrast of the fistula tract of the intestine and urinary tract.

With survey and excretory urography, it is possible to detect stones and foreign bodies in the lumen of the urinary tract or intestine, to assess renal function and the tone of the upper urinary tract. With renal and ureteral-intestinal fistulas, ectasia and deformation of the calyces and pelvis, and decreased renal function are noted on the affected side. With descending cystography, as a result of the contrast agent entering the sigmoid and rectum, it is possible to determine the contours of the latter (in vesicointestinal fistulas). In renal and ureteral-intestinal fistulas, retrograde ureteropyelography is informative.

With retrograde cystography, which should be performed in two projections and with a tightly filled bladder, it is possible to detect the leakage of contrast medium into the intestine.

CT with contrast is the most sensitive method for diagnosing enterocystic fistulas and should be included in the standard examination for this disease.

MRI is effective for the diagnosis of deep perineal fistulas (use as indicated).

X-ray contrast examination of the intestine does not always allow detection of ureteral fistula, but helps in the differential diagnosis of diverticulosis and intestinal neoplasms.

The introduction of a colored solution into the bladder improves the visualization of the fistula opening during rectoscopy and colonoscopy. With their help, it is possible to determine the intestinal disease that caused the fistula, the location and size of the latter, the degree of perifocal inflammation, and perform a targeted biopsy.

Cystoscopy is one of the most informative methods of examination, allowing not only to visually determine the presence of a fistula, but also to perform a biopsy to exclude an oncological process. Limited hyperemia, papillary or bullous changes in the mucous membrane, mucus or particles of feces in the bladder are found in 80-90% of patients. Due to the development of bullous edema of the mucous membrane, it is not always possible to determine the fistula tract. In this case, it is advisable to try to catheterize and contrast the latter. It should be remembered that fistulas are most often located in the apex of the bladder.

Considering that enterovesical fistulas (the most common) occur as a result of a primary bowel disease, a surgeon should be involved in the diagnostic process and determination of treatment tactics.

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Treatment ureteric fistulas

Conservative treatment of renal and ureteric-intestinal fistulas is ineffective. The constant flow of intestinal contents, accompanied by an exacerbation of pyelonephritis, contributes to the development of its purulent forms and sepsis, which is considered an indication for early surgical treatment.

In some cases, it is advisable to conduct conservative treatment for small vesicointestinal fistulas caused by diverticulosis of the sigmoid colon or Crohn's disease in weakened, severely somatic patients as a preparation for surgical intervention. Sulfonamides, metronidazole, broad-spectrum antibiotics, glucocorticoids, mercaptopurine, etc. are prescribed.

Surgical intervention aimed at closing the ureteral fistula and eliminating the disease that caused it is the main and radical method of treatment.

Surgical treatment of ureteral fistulas

Radical surgical treatment of ureteral fistulas. Indication - ureteral fistula. The standard method of surgical treatment is considered to be the performance of one-stage or multi-stage fistuloplasty with the removal of the pathological focus that caused the formation of the fistula.

Multi-stage fistuloplasty involves preliminary derivation of urine and feces. In case of renal and ureteral fistulas, there may be a need for sanitation of the purulent focus and drainage of the retroperitoneal tissue. Violation of urodynamics requires nephrostomy. Multi-stage intervention, which is easier for patients to tolerate, causes fewer postoperative complications.

A one-stage operation is performed outside of the exacerbation of the inflammatory process (pyelonephritis, cystitis, colitis) and with preserved function of the kidneys, urinary tract and intestines. It significantly reduces the time of treatment and rehabilitation of patients.

A one-stage operation for renal-intestinal fistulas is usually performed through the lumbar approach. First, an operation is performed on the kidney (in most cases, nephrectomy is indicated), then a thorough excision of the fistula is performed. The next stage is an operation on the intestine, the volume of which depends on the nature of the primary disease, the patient's condition, and the location of the fistula opening. The operation is completed by drainage of the retroperitoneal tissue.

The most common surgical intervention for entero-ureteral fistulas with purulent lesions and loss of renal function is nephroureterectomy. The fistula opening of the intestine is sutured, less often its resection is performed. With good renal function, organ-preserving operations are performed: resection of the ureter with the imposition of ureterocystoanastomosis, Boari operation or intestinal ureteroplasty.

A one-stage operation for vesicointestinal fistulas is performed through the lower midline transperitoneal approach. During revision of the abdominal cavity, the condition of its organs is determined, primarily those involved in the formation of the fistula. The intestinal loops, the wall of the bladder, and the area of the fistula are mobilized bluntly and sharply. During further isolation, it is advisable to go around the area of the latter, after which the wall of the bladder is opened at a distance of 1.5-2 cm from the fistula opening and the bladder is separated from the fistula conglomerate and the intestine by a bordering incision.

If it is necessary to determine the etiology of the bowel and bladder disease, an emergency biopsy is performed, followed by a revision of the bladder. In the absence of other pathological changes requiring surgical correction, it is tightly sutured with a two-row continuous interrupted vicryl suture with drainage through the urethra with a Foley catheter. In some cases (severe cystitis, IVO, hypotension of the m. detrusor urinae, etc.), epicystostomy is performed. Subsequently, an operation is performed on the intestine, the scope of which depends on the characteristics of the detected disease, the degree of prevalence of the pathological process and the state of the gastrointestinal tract.

When the urinary bladder communicates with the vermiform appendix, an appendectomy is performed. The method of choice for small intestinal fistula is intestinal resection with restoration of intestinal patency by the "end-to-end" or "side-to-side" type. Vesicointestinal fistula that occurs as a result of intestinal diverticulosis requires careful revision of the mobilized intestine to detect areas with diverticula. In case of isolated diverticula in a limited area of the intestine, excision of the fistula tract within healthy tissues with suturing of the sigmoid colon defect in the transverse direction with a two-row vicryl suture is acceptable.

In case of multiple diverticulitis leading to destructive changes in the wall of the sigmoid colon, formation of dolichosigma or tumor lesions of the organ, it is necessary to remove the sigmoid colon within healthy tissues with the imposition of an end-to-end anastomosis and a two-row continuous interrupted vicryl suture.

The abdominal cavity is drained with silicone tubes and sutured layer by layer.

Multi-stage operations are recommended for acute onset of the disease, inflammatory infiltrate, large pelvic abscesses, radiation injuries, intoxication, and also for severe cancer patients. At the first stage, it is necessary to perform a colostomy and divert urine. After the patient's general condition improves (on average, after 3-4 months), fistuloplasty can be performed.

Surgical treatment of high-risk patients consists of complete drainage of the bladder using a Foley catheter or epicystostomy. Fecal drainage is performed using a colostomy.

Prevention

Uroenteric fistulas can be prevented. This prevention consists of timely diagnosis and treatment of inflammatory diseases and neoplasms of the kidneys, urinary tract and intestines. When performing such common surgical interventions as TUR of the prostate and bladder neck, RP, laparoscopic operations, as well as brachytherapy for prostate cancer, one should remember and avoid the possibility of combined injury to the wall of the urethra, bladder and intestines.

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Forecast

The prognosis of ureteral fistulas depends on the severity of the primary disease that caused the ureteral fistula. It should be noted that spontaneous healing of ureteral fistulas is extremely rare, so a good prognosis is associated with timely and high-quality surgical treatment.

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