Enterovesical Fistula 

Enterovesical Fistula

Description

•  condition with abnormal anatomical communication between the bowel and the bladder, often due to advanced-stage inflammatory conditions, malignant disease, or traumatic or iatrogenic injuries^(1,2)

Also called

•  vesicoenteric fistula
•  intestinovesical fistula

Types

• classification of enterovesical fistula based on bowel segment involved^(1,2)
  •  colovesical (accounts for the majority of cases – usually located between the sigmoid colon and bladder dome)
  •  rectovesical (including rectourethral)
  •  ileovesical
  •  appendicovesical (reported in < 5% of cases)

Epidemiology

Who is most affected

• more common in men than women (3:1 ratio)⁽²⁾
  •  risk is less in women due to the interposition of the uterus between bladder and sigmoid colon
  •  women who develop enterovesical fistulas often have had a previous hysterectomy
•  most common in patients aged 50-70 years⁽²⁾

Incidence/Prevalence

•  uncommon⁽¹⁾
•  1 in every 3,000 surgical hospital admissions reported to be for enterovesical fistula⁽¹⁾

Likely risk factors

•  male gender^(1,2)
•  age ≥ 50 years⁽²⁾
•  history of surgery or procedures for diverticulitis, inflammatory bowel disease, or colorectal cancer^(1,2)

Etiology and Pathogenesis

Causes

• advanced-stage inflammatory bowel disease (reported to account for about 80% of cases), including^(1,2)
  • diverticulitis (reported in about 65%-79% of enterovesicular fistulas, almost all colovesicular)
  • Crohn disease (reported in about 10% of enterovesicular fistulas, and the most common cause of ileovesical fistula)
  • less commonly
    • appendicitis
    • Meckel diverticulum
    • genitourinary coccidioidomycosis
    • pelvic actinomycosis
    • tuberculosis
    • syphilis
• neoplastic disease (reported to account for about 20% of cases), including^(1,2)
  • colorectal cancer
  • bladder cancer (rare)
  •  other cancers (rare), including cervix, prostate and ovary, lymphoma, colonic carcinosarcoma
• trauma^(1,2)
  •  penetrating abdominal or pelvic injuries
  • iatrogenic due to
    •  surgery or procedures for diverticulitis, colorectal cancer, or inflammatory bowel disease
    •  radiation (external beam or brachytherapy) – usually develop years after treatment for gynecological or urological malignancies
    •  chemotherapy (extremely rare) (Int Urol Nephrol 2001;33(2):373)
  • foreign bodies in bowel and peritoneum (rare), such as
    •  catheters in bladder
    •  fish or chicken bones in bowel

Pathogenesis

•  direct extension of ruptured diverticulum or erosion of peridiverticular abscess into bladder^(1,2)
•  transmural inflammation in Crohn colitis may result in adherence to bladder with subsequent erosion and further fistula formation⁽¹⁾
•  radiation may induce progressive endarteritis obliterans, leading to necrosis and breakdown of mucosal surfaces⁽¹⁾

History and Physical

Clinical presentation

• usually present with lower urinary and/or gastrointestinal tract signs and symptoms^(1,2)
  •  common presentation includes suprapubic pain, frequency, dysuria, and tenesmus (Gouverneur syndrome)
  • characteristic features include
    •  recurrent urinary tract infection (UTI) (reported in 70%-80%)
    • pneumaturia
      •  reported in about 60%
      •  more likely to occur with inflammatory disease than with cancer
    •  fecaluria (reported in about 40%)
  • other presentations may include
    •  urgency
    •  hematuria
    •  alteration of bowel habit
    •  hematochezia
    •  urinary flow via rectum
    •  diarrhea
    •  abdominal pain
    •  orchitis
    •  malodorous urine
    •  combination of these symptoms
•  symptoms of underlying disease may also be present (such as abdominal pain in patients with Crohn disease)⁽¹⁾
•  may have metabolic acidosis (extremely rare)⁽²⁾

History

Past medical history (PMH)

• ask about history of^(1,2)
  • inflammatory bowel disorders, such as diverticulitis or Crohn disease
  • colorectal cancer or other neoplastic disease
  •  recurrent urinary tract infection (UTI)
  •  radiation therapy to pelvis
  •  pelvic trauma

Physical

General physical

•  may have fever (uncommon)^(1,2)

Abdomen

•  patients with fistulating Crohn disease may present with symptoms of the underlying disease, including abdominal tenderness and mass⁽¹⁾

Rectal

•  may have tenesmus or local pain⁽¹⁾
•  while digital rectal exam has no absolute contraindications, avoid vigorous manipulation, especially of the prostate, in patients with severe neutropenia and those with prostatic abscesses or prostatitis

Diagnosis

Making the diagnosis

•  the diagnosis of enterovesical fistulas can be difficult, and many patients may be symptomatic for months prior to being properly diagnosed and treated⁽²⁾
• diagnosis suspected in patients with advanced stage inflammatory bowel disease or neoplastic disease (particularly colorectal cancer) and signs and symptoms associated with enterovesical fistula, including^(1,2)
  •  suprapubic pain, frequency, dysuria, and tenesmus (Gouverneur syndrome)
  •  pneumaturia, fecaluria, and recurrent urinary tract infection (UTI)
• diagnosis can be confirmed via imaging studies, with key findings including^(1,2)
  •  air in bladder (pathognomonic)
  •  oral contrast medium in bladder on non-IV contrast-enhanced scans
  •  presence of colonic diverticula
  •  bladder wall thickening adjacent to loop of thickened intestine

Differential diagnosis

•  other causes and associated conditions of urinary tract infection (UTI)
• other causes of pneumaturia, including⁽²⁾
  •  recent bladder instrumentation
  •  emphysematous cystitis
  •  rare urinary tract infections caused by gas-forming organisms (strains of Escherichia coli, Pseudomonas, and yeast in patients with diabetes)

Testing overview

• diagnostic testing is necessary to⁽¹⁾
  •  confirm diagnosis of a fistula
  •  exclude stricture of the bowel and identify the presence of abscess
  •  evaluate the anatomical region of involved intestine to guide surgery
• while there is no consensus on an optimal testing algorithm for diagnosing enterovesical fistula, a proposed algorithm for diagnosis includes⁽¹⁾
  • ultrasound of the abdomen and pelvis (in some cases, the fistula may be identified by ultrasound without the need for additional imaging or more invasive testing)
  • poppy seed urine test
  •  abdominopelvic computed tomography with contrast and/or magnetic resonance imaging if patient has contraindications to radiation or contrast, or if a complex fistula is present
  • cystoscopy with biopsy, with or without colonoscopy with biopsy in patients with colovesical fistula
•  blood tests are typically not performed because they are usually within the normal range⁽²⁾

Urine studies

• urinalysis may show⁽²⁾
  •  leukocytes
  •  bowel organisms
  •  fecaluria
  •  urinary debris or vegetable matter
•  urine culture usually shows mixed flora, most commonly Escherichia coli⁽²⁾
•  urine cytology may show smooth muscle fibers from gastrointestinal tract⁽²⁾
• poppy seed test^(1,2)
  •  oral intake of 50 mg of poppy seeds mixed in a drink or yogurt
  •  seeds remain largely undigested through gastrointestinal tract, and presence in urine within 48 hours following intake considered positive confirmatory test for enterovesical fistula, but does not define location or type of fistula
  •  reported to have a near 100% detection rate for fistulas
• other testing may include
  • Bourne test^(1,2)
    •  radiographic examination of centrifuged first urine sample obtained immediately after nondiagnostic barium enema
    •  presence of radiodense particles in urine sediment confirms fistula diagnosis
    •  reported to improve detection rate for colovesical fistulas to 90%
    • limitations to use include
      •  need for contrast enema (contrast may be too viscous to pass through small fistulas)
      •  radiation exposure
      •  need for bowel preparation (colonic purgatives)
  • oral activated charcoal test⁽²⁾
    •  inexpensive, can be administered at home or bedside with home urine collection
    •  positive test defined as presence of charcoaluria (blackened urine) within 24 hours
    •  reported to be up to 100% sensitive for presence of fistula, but cannot identify location
  • use of coloring agents
    •  orally or rectally administrated indocyanine green is reported to be highly specific for fistula⁽²⁾
    •  distention of bladder with methylene blue solution instilled through catheter may identify invisible fistulous tract opening^(1,2)

Imaging studies

Ultrasound

• in some cases, colovesical fistula may be diagnosed by abdominopelvic ultrasound without the need for additional imaging or more invasive testing⁽¹⁾
  •  reported detection rate near 100% in small series
  • abdominal compression technique increases yield of transabdominal ultrasound
    •  may reveal echogenic “beak sign” connecting peristaltic bowel lumen and urinary bladder
    •  may identify ureteric orifices with associated urinary jets
•  anorectal, transrectal, and transvaginal ultrasound can help identify a fistulous tract, and its relation to the adjacent anatomical structures⁽¹⁾

Computed tomography (CT)

• CT with oral contrast is the most effective modality for definitive diagnosis of enterovesical fistula, but exposure to radiation limits its use^(1,2)
  •  reported to have high sensitivity for diagnosis
  •  able to provide additional information about adjacent anatomical structures, including any pericolic complications of diverticular disease
  •  represents the main diagnostic method to identify intra-abdominal collections, and allows for diagnosis and staging of a colonic malignancy
  • other advantages include
    •  allows percutaneous placement of catheters
    •  relatively inexpensive cost
    •  noninvasive (can be used in elderly or sick patients)
    •  widely available
  • limitations include
    •  radiation exposure
    •  need for direct opacification – dilution of hydrosoluble contrast agents in the bowel limits the diagnostic value, and false-negatives can occur in cases with edematous occlusion of the fistulous tract preventing opacification
•  perform CT following oral administration of contrast but prior to IV administration of contrast, in order to permit detection of Gastrografin or other diluted iodinated contrast agents within the bladder⁽¹⁾
• key findings suggestive of enterovesical fistula include^(1,2)
  • air in bladder (pathognomonic), however false-positives may occur if
    •  recent lower urinary tract instrumentation
    •  active urinary tract infection with gas-forming organisms
  •  oral contrast medium in bladder on non-IV contrast-enhanced scans
  •  presence of colonic diverticula
  •  bladder wall thickening adjacent to loop of thickened intestine
•  three-dimensional CT may provide better anatomical visualization but too costly for routine use⁽²⁾
• CT of abdominal and pelvic area may help diagnose vesicoenteric fistulae (level 2 [mid-level] evidence)
  •  based on diagnostic cohort study without diagnostic uncertainty
  • 51 patients (median age 55 years, 80% male) with surgically confirmed vesicoenteric fistulae secondary to diverticular disease were assessed
  • 94% had CT scan of abdominal and pelvic area
  • sensitivity of CT for detecting vesicoenteric fistulae
    • 100% without IV contrast
    • 89% with IV contrast
    • 83% with IV and oral contrast
  • Reference – Int Urol Nephrol 2020 Jul;52(7):1203

Magnetic Resonance Imaging (MRI)

•  MRI identifies fistulous tract without need for direct opacification required in CT scanning^(1,2)
•  for colovesical fistula, sensitivity and specificity reported to be near 100%; however not widely used for diagnosis due to lack of availability in the emergency setting and high cost⁽¹⁾
• technique^(1,2)
  •  use of combined sequences ideal because appearance of fistula on MRI dependent on contents (fluid, air, or combination).
  • if fluid filled
    •  T1-weighted images delineate extension of fistula relative to sphincters and adjacent hollow viscera and show inflammatory changes in fat planes
    •  T2-weighted images show fistula typically as high-signal-intensity, fluid-filled communication
  •  air-filled fistulous tract seen as low signal intensity, regardless of pulse sequence use
  •  if fistulas due to diverticulitis, abscess (containing high-signal fluid on T2-weighted images) commonly seen lying between inferior wall of sigmoid colon and thickened, inflamed superior bladder wall
  • IV gadolinium enhancement
    •  improves detection of bladder fistulas
    •  early postgadolinium T1-weighted images show enhancement of tract walls and signal void fluid centrally
    •  axial and sagittal planes useful for detection of enterovesical fistulas
•  may identify focal defect in bladder muscle⁽²⁾

Other radiographic examinations

•  abdominal x-ray is generally not helpful, unless air-fluid level in bladder seen when patient standing^(1,2)
•  IV urography rarely demonstrates fistula, unless patient has severe outlet obstruction⁽¹⁾
• barium enemas (BE)^(1,2)
  •  limited role in diagnosis of enterovesical fistulas due to low sensitivity (reported to be about 30%) and availability of CT scanning
  •  may be useful in differentiating diverticular disease from colonic cancer as underlying cause
• cystography^(1,2)
  •  may demonstrate contrast outside bladder but less likely to demonstrate fistula
  •  detection rate reported to be 20%-30%
  • diagnostic signs
    •  herald sign – crescentic defect on upper margin of bladder (represents perivesical abscess)
    •  beehive sign (pathognomonic for colovesical fistula) – elevation of bladder wall at vesical end of fistulous tract
• Tc-99m diethylenetriamine pentaacetate (DTPA) scan⁽¹⁾
  •  simple and widely available tool for anatomic and functional urinary tract information
  •  may demonstrate presence and location of fistula with passage of radioactive urine from urinary system into bowel
  •  urine flow rate may show fistula severity

Endoscopy

• cystoscopy (endoscopy of the bladder via the urethra) is an essential component of investigation and some clinicians recommend it as the first-choice procedure⁽²⁾
  •  can suggest the presence of a fistula (intravesical edema suggestive of a fistulous tract, or the presence of stool and mucus in the bladder) and help exclude rare urological malignancy
  • findings are usually nonspecific and may include
    •  presence of localized area of erythema or edema and congestion (typical early finding)
    •  bullous edema and mucosal papillomatous hyperplasia surrounding fistula (later sign)
  •  reported to fail to identify fistula in about 50% of patients
•  colonoscopy may help identify neoplasms and other bowel pathology contributing to fistula formation, but is not accurate for diagnosis of fistula itself⁽²⁾

Management

Management overview

• surgery indicated in all patients with enterovesical fistula if patient is healthy enough for surgery
  •  choice of procedure varies by underlying pathology, site of bowel lesion, and patient’s preoperative status
  • resection and primary anastomosis can be performed as a single-stage or multistage procedure
    •  single-stage resection and primary anastomosis (without a protective colostomy) is suggested for most patients, and preferred over multistage procedures when possible
    • multistaged procedures are typically reserved for patients with gross fecal contamination of the abdomen and/or pelvis and large pelvic abscesses, or in those with advanced malignancy or radiation changes
      •  2-stage resection (also known as the Hartmann procedure) – resection and primary anastomosis with a protective colostomy
      • 3-stage resection – Hartmann procedure with later closure of stoma
        •  only indicated if very high surgical risk
        •  rarely used
  • laparoscopic approach is routinely used in surgical procedures for enterovesical fistula repair; however endoscopic (minimally invasive) and open approaches have been used
  • up to 50% of patients may have complications following surgery, including
    •  infection
    •  anastomotic leakage
    •  pelvic/abdominal abscess
    •  cutaneous fistulas
    •  intestinal obstruction
    •  persistent bladder leakage (usually after pelvic radiation therapy)
    •  fistula recurrence (also more likely after pelvic radiation therapy)
• nonoperative/conservative management may be an option in select patients but associated with increased risk for septic complications compared to surgery
  • typically reserved for patients with
    •  contraindications to major surgery due to poor overall health
    •  inability to tolerate general anesthesia
    •  extensive unresectable neoplastic process
    •  terminal cancer
  • may include a trial of
    •  bowel rest
    •  total parenteral nutrition
    • medications, including antibiotics, steroids, or immunomodulatory drug therapy
    •  urethral catheter drainage
  • in patients at high surgical risk or with terminal cancer
    •  approach may include medical therapy with catheter drainage of the bladder alone, or supravesical percutaneous diversion
    •  most patients will ultimately require a diverting colostomy as the disease progresses
•  treatment outcomes and prognosis are largely dependent on underlying cause of fistula, as patients with malignant causes are likely to have worse outcomes

Conservative management

• nonoperative/conservative management may be an option in select patients but associated with increased risk for septic complications compared to surgery⁽²⁾
  • typically reserved for patients with⁽²⁾
    •  contraindications to major surgery due to poor overall health
    •  inability to tolerate general anesthesia
    •  extensive unresectable neoplastic process
    •  terminal cancer
  •  has been used as first-line treatment in some nontoxic, minimally symptomatic patients with nonmalignant enterovesical fistula, such as those with Crohn disease^(1,2)
• treatment approach
  • may include a trial of⁽¹⁾
    •  bowel rest
    •  total parenteral nutrition
    • medications, including antibiotics, steroids, or immunomodulatory drug therapy
    •  urethral catheter drainage
  • in patients at high surgical risk or with terminal cancer^(1,2)
    •  approach may include medical therapy with catheter drainage of the bladder alone, or supravesical percutaneous diversion
    •  most patients will ultimately require a diverting colostomy as the disease progresses
• patients treated conservatively may have a high mortality associated with poor health, progression of malignant disease, and the septic effects of the fistula; however in patients with benign, non-radiation-induced fistula, risk for disease-specific mortality may be similar compared to patients treated surgically
  •  mortality due to progression of malignancy in 3 of 5 patients with colovesical fistula managed conservatively in case series (Colorectal Dis 2005 May;7(3):286)
  • surgical and conservative therapy may be associated with similar disease-specific mortality in patients with benign colovesical fistula (level 2 [mid-level] evidence)
    •  based on retrospective cohort study
    • 50 patients (mean age 71 years) with colovesical fistula were evaluated
      •  6 patients were treated with conservative management
      •  44 patients were treated surgically
    •  78% of patients had diverticular disease as the underlying cause
    •  no significant differences in disease-specific mortality comparing conservative management to surgical management at 5 years
    •  patients with a malignant colovesical fistula had a significantly worse overall survival (median survival 12 months) than patients with a colovesical fistula due to benign causes (p < 0.001)
    •  Reference – Colorectal Dis 2005 Sep;7(5):467

Medications

• antibiotics may be part of an appropriate treatment strategy for patients with underlying diverticulitis
  •  in patients with complicated diverticulitis (including those with fistula), American Society of Colon and Rectal Surgeons (ASCRS) suggests considering IV antibiotics that target gram-negative bacteria and anaerobes (Dis Colon Rectum 2014 Mar;57(3):284)
  • for severe symptoms and inpatient management
    • suggested first-line regimens include 1 of
      • imipenem-cilastatin 500 mg IV every 6 hours
      • meropenem 1 g IV every 8 hours
      • doripenem 500 mg IV every 8 hours
    • suggested second-line regimens include 1 of
      • ampicillin 2 g IV every 6 hours plus metronidazole 500 mg IV every 6 hours plus either ciprofloxacin 400 mg IV every 12 hours or levofloxacin 750 mg IV every 24 hours
      • ampicillin 2 g IV every 6 hours plus metronidazole 500 mg IV every 6 hours plus 1 of amikacin (no dose specified), gentamicin (no dose specified), or tobramycin (no dose specified)
    •  Reference – Am Fam Physician 2013 May 1;87(9):612full-text, summary can be found in Am Fam Physician 2013 May 1;87(9):612s1full-text
• medical management of fistulizing Crohn disease may include antibiotics, azathioprine, 6-mercaptopurine, and antitumor necrosis factor agents
  • adalimumab and certolizumab pegol may be effective in fistula closure maintenance (but not fistula improvement or likelihood of closure) in adults with fistulizing Crohn disease (level 2 [mid-level] evidence)
    •  based on systematic review of randomized trials with unclear allocation concealment
    •  systematic review of 9 randomized trials comparing tumor necrosis factor antagonists (infliximab, adalimumab, and certolizumab pegol) to placebo in 774 patients with fistulizing Crohn disease
    •  allocation concealment not assessed in any trials
    •  compared to placebo, antitumor necrosis factor-alpha antibodies (adalimumab and certolizumab pegol) associated with increased rate of fistula closure maintenance (maintaining remission in patients whose fistula has closed) (risk ratio 2.36, 95% CI 1.58-3.55) in analysis of 2 trials with 368 patients
    • no significant differences between groups in
      •  fistula improvement (closure of 50% of fistula for at least 2 consecutive visits) in analysis of 2 trials with 123 patients
      •  fistula closure (closure of 100% of fistula for at least 2 consecutive visits) in analysis of 2 trials with 193 patients
    •  Reference – J Res Pharm Pract 2017 Jul-Sep;6(3):135full-text
  • medical therapy reported to benefit some patients with enterovesical fistulas and Crohn disease (level 3 [lacking direct] evidence)
    •  based on systematic review of case series and case reports
    • systematic review of 23 case series and case reports evaluating medical management (alone or in combination with surgery) of enterovesical or rectovaginal fistula in 181 patients with Crohn disease
      •  44 patients had enterovesical fistulas
      •  137 patients had rectovaginal fistula
    •  medical therapy included various combinations of steroids, antibiotics, sulfasalazine, azathioprine, and immunosuppressants
    • in patients with enterovesical fistulas
      •  medical therapy had 65.9% complete response, 20.5% partial response, and 13.6% no response
      •  antitumor necrosis factor therapy (alone or in combination with medications including antibiotics, sulfasalazine, and immunosuppressants) in 14 patients had 57.1% complete response, 35.7% partial response, and 7.1% no response
    •  Reference – J Clin Gastroenterol 2016 Oct;50(9):714

Surgery and procedures

• surgery indicated in all patients with enterovesical fistula if patient is healthy enough for surgery; contraindications to surgery may include⁽²⁾
  •  poor overall health
  •  inability to tolerate general anesthesia
  •  extensive unresectable neoplastic process
  •  terminal cancer
• goals of operative management^(1,2)
  •  resect and reanastomose diseased bowel segment (essential for prevention of recurrence)
  •  close bladder opening if large, or leave open if small for spontaneous closure
• choice of procedure dependent on^(1,2)
  • underlying pathology – radiation-induced enterovesical fistulas difficult to manage with surgical approach due to
    •  extensive fibrosis of tissue planes
    •  high risk of recurrence
  •  site of bowel lesion – distention of bladder with methylene blue solution instilled through catheter may help identify invisible fistulous tract opening
  •  patient’s preoperative status
• procedure options
  • resection and primary anastomosis can be performed as a single-stage or multistage procedure^(1,2)
    • single-stage resection and primary anastomosis without a protective colostomy is suggested for most patients, and preferred over multistage procedures when possible
      •  associated with 18%-92% reported success rate, with substantial improvements in patient’s quality of life
      •  interposition of omental flap between bladder and intestine may improve healing process and reduce fistula recurrence rate (due to omental immunological properties and high vascularity)
    • multistaged procedures are typically reserved for patients with gross fecal contamination of the abdomen and/or pelvis and large pelvic abscesses, or in those with advanced malignancy or radiation changes; options include
      •  2-stage resection (also known as the Hartmann procedure) – resection and primary anastomosis with a protective colostomy
      • 3-stage resection – Hartmann procedure with later closure of stoma
        •  only indicated if very high surgical risk
        •  rarely used
    •  use of a defunctioning ileostomy for patients with primary anastomosis after colonic resection can help reduce complications associated with anastomotic leakage (J Gastrointest Surg 2012 Aug;16(8):1559)
    • single-stage surgery reported to be effective for most patients with colovesical or colovaginal diverticular fistula (level 3 [lacking direct] evidence)
      •  based on case series
      • 16 patients (11 men, 5 women) who had surgery for colovesical or colovaginal diverticular fistulas evaluated
        •  75% (12 patients) had single-stage procedure
        •  18.8% (3 patients) had 2-stage procedure
        •  6.3% (1 patient) had defunctioning colostomy
      •  open procedure in 12 patients, laparoscopic surgery in 4 patients
      •  overall complication rate 31.2%, recurrence in 1 patient
      •  Reference – Ann Ital Chir 2017;88:55
    • colonic resection and primary anastomosis reported to be effective with low morbidity for most patients with colovesical diverticular fistula (level 3 [lacking direct] evidence)
      •  based on case series
      •  90 patients with colovesical fistula were evaluated, including 75% with underlying diverticular disease
      • most common surgical treatments included
        •  left-sided colonic resections in 73.6%
        •  defunctioning loop colostomies in 18.5%
        •  right hemicolectomy in 4.2%
      • in 48 patients having left-sided resection
        •  primary anastomosis successfully achieved in 92% of patients
        •  1 postoperative leak and no deaths were reported
      •  in 18 patients not treated surgically, 7 deaths (38.9%) reported at 1-year follow-up
      •  Reference – Colorectal Dis 2006 May;8(4):347
  • proximal defunctioning procedures have been used as the sole intervention, but are unlikely to result in fistula tract closure^(1,2)
    •  associated with low surgical trauma
    •  fistula often recurs following reversal of colostomy with risk of urinary sepsis
    •  may be a reasonable option to improve quality of life in patients with radiation-induced enterovesical fistulas
• laparoscopic approach is routinely used in surgical procedures for enterovesical fistula repair; however endoscopic (minimally invasive) and open approaches have been used^(1,2)
  • laparoscopic approach
    • laparoscopic management reported to be effective with moderate complication rates in most patients with colovesical fistula (level 3 [lacking direct] evidence)
      •  based on 3 case series
      • 15 patients with diverticular colovesical fistula who had laparoscopic-assisted anterior resection and bladder repair evaluated
        •  33.3% (5 patients) required conversion to open procedure
        •  20% morbidity rate
        •  no recurrence reported during median follow-up 12.4 months
        •  no deaths reported
        •  Reference – Int Surg 2013 Apr;98(2):101full-text
      • 43 patients with diverticular (24 patients) or Crohn disease (19 patients) who had laparoscopic surgery for colovesical, colovaginal, enterovesical, and enterocolic fistulas evaluated
        •  32.6% (14 patients) required conversion to open procedure for dense adhesions, duodenal involvement, multiple fistulas, fecal leak, and additional pathology
        • complications included
          •  major complications in 14%, including anastomotic leak, abscesses, and postoperative bleeding
          •  minor complications in 16.3%, including postoperative ileus, transient pleural effusion, wound infection, transient small bowel obstruction, and brachial plexus neuralgia
        •  Reference – Surg Endosc 2005 Feb;19(2):222
      • 18 patients with fistulating diverticular disease (15 with colovesical fistulas and 3 with colovaginal fistulas) had single-stage laparoscopic surgery
        •  treatments included 12 sigmoidectomies, 4 extended left colectomies, and 2 segmentectomies
        •  1 patient required conversion to open procedure
        •  27.7% morbidity rate, including 1 major complication
        •  1 fistula recurrence (5.5%) and no recurrent diverticulitis reported during the 5.1-year follow-up period
        •  no deaths reported
        •  Reference – Langenbecks Arch Surg 2003 Jul;388(3):189
  • endoscopic approach
    • in patients with enterovesical fistula due to colorectal cancer⁽¹⁾
      •  endoscopic approach is often associated with bowel stenosis and requires the use of covered self-expanding metal stents (SEMS)
      •  benefits include maintains lumen patency while allowing for the application of stents within the stenotic bowel segment, even in patients with weakened, neoplastic tissue
    •  in patients with iatrogenic enterovesical fistula following colorectal surgery, endoscopic closure of perforations < 1 cm is an option⁽²⁾
    • in patients with enterovesical fistula due to diverticulitis^(1,2)
      •  endoscopic approach is typically contraindicated in patients with diverticulitis due to high risk of colon perforation with stent placement; however successful stenting of colonic strictures in patients with enterovesical fistulas has been reported
      •  in patients with diverticular disease without stenosis, application of endoscopic clips may help manage the condition (nitinol metal clips reported to have improved strength and grip on tissue compared to traditional clips delivered through the flexible endoscope)
• management of bladder during surgery for enterovesical fistula⁽²⁾
  •  type of bladder repair (excision or oversewing) not critically important
  •  small defects do not require any closure
  •  outcome not affected by choice of suture, number of closure layers, or type of postoperative bladder drainage
  •  if neoplasia suspected, partial cystectomy with healthy resection margin required to minimize incidence of local recurrence
  •  bladder catheterization for 7-10 postoperative days may help bladder healing
  •  routine ureteric catheterization may not be necessary
• up to 50% of patients may have complications from surgery⁽²⁾
  •  short-term complications may include those seen after any major abdominal operation, such as infection, bleeding, and pain
  • long-term complications may include
    •  anastomotic leakage
    •  pelvic/abdominal abscess
    •  cutaneous fistulas
    •  intestinal obstruction
    •  persistent bladder leakage (usually after pelvic radiation therapy)
    •  fistula recurrence (also more likely after pelvic radiation therapy)
• recurrence and postoperative death each reported in 5% of adults having surgery for enterovesical and/or colovesical fistulas (level 3 [lacking direct] evidence)
  • based on noncomparative data in systematic review of observational studies
  • systematic review of 22 observational studies, including 13 case series, evaluating surgical management of enterovesical and/or colovesical fistulas in 861 adults
  • most common etiology of enterovesical and/or colovesical fistulas was benign disease (diverticular disease in 60% and Crohn disease in 28%)
  • follow-up varied across studies: mean 53 months in 7 studies, 2-108 months in 1 study, and median 34 months in remaining studies
  • surgery included 1-stage primary resection and anastomosis in 76%, multistage resection and primary anastomosis plus colostomy and/or Hartmann procedure with or without later closure of stoma in 16%, and palliative interventions including definitive ileostomy or colostomy in 6%
  • clinical outcomes after surgical repair
    • recurrence rate 5% (95% CI 3.4%-7.3%) in analysis of all studies
    • complication rate 22.2% (95% CI 17%-28.6%) in analysis of 19 studies with 708 patients, results limited by significant heterogeneity
    • postoperative mortality 4.9% (95% CI 3.3%-7.4%) in analysis of 19 studies with 637 patients
  • Reference – BMC Surg 2021 May 27;21(1):265full-text
• among adults having surgery for colovesical fistula, complications reported in 38.4% and recurrence in 1.2% at mean follow-up of 5-68 months (level 3 [lacking direct] evidence)
  •  based on noncomparative data in systematic review of observational studies
  • systematic review of 22 observational studies (mostly case series) evaluating management and postoperative outcomes in 1,365 adults with colovesical fistula
    • median patient age ranged from 53 to 76 years
    • most common etiology of colovesical fistula was colonic diverticulitis (in 87.9% of patients)
  • among 1,325 patients who had surgery, most patients had colorectal resection with primary anastomosis with or without ostomy
    • 63.3% had open surgery, 35.1% had minimally invasive laparoscopy, and 1.6% had minimally invasive robotic surgery
    • 60.5% had sigmoidectomy or hemicolectomy, 19.1% had anterior rectal resection, 9.9% had unspecified colectomy, and 5.2% had Hartmann procedure
  • clinical outcomes after surgery
    • overall complication rate 38.4% in 18 studies
    • recurrence rate 1.2% at mean follow-up of 5-68 months in 14 studies
    • mortality ranged from 0% to 63.2% at mean follow-up of 5-68 months in 19 studies
  • among patients having colectomies with primary anastomosis, complications included anastomotic leak in 4%, reoperations in 3.1%, and bladder leak in 1.8%
  • Reference – Minerva Urol Nephrol 2022 Aug;74(4):400full-text

Complications and Prognosis

Complications

•  frequent urinary tract infection (UTI) (sepsis rare)⁽²⁾

Prognosis

•  prognosis is largely dependent on underlying cause of fistula, as patients with malignant causes are likely to have worse outcomes⁽²⁾
•  about 2% of small defects reported to heal spontaneously⁽¹⁾
•  surgical management of benign enterovesical fistulas without radiation exposure usually results in excellent outcomes, and postoperative recurrence is uncommon^(1,2)
•  radiation-induced fistulas are more likely to recur, but long-term prognosis may be improved if the underlying malignancy requiring radiation has been controlled⁽²⁾
• reported mortality rates of patients who have surgery for enterovesical fistula has decreased due to better intensive care, but mortality rates in this population are still relatively high, often related to underlying condition and patient’s general health⁽²⁾
  •  up to 19.5% perioperative mortality
  •  up to 60% 5-year mortality
• persistence of fistula after presumably definitive treatment may be caused by^(1,2)
  •  malignancy
  •  nutritional issues
  •  unrecognized foreign body
  •  surgical factors

Prevention and Screening

Prevention

•  avoid bladder injury during pelvic surgery or procedures involving bowel or bladder^(1,2)

Screening

•  not applicable

Guidelines and Resources

Guidelines

• American Society of Colon and Rectal Surgeons (ASCRS) clinical practice guidelines on
  •  treatment of colon cancer can be found in Dis Colon Rectum 2017 Oct;60(10):999
  •  surgical management of Crohn disease can be found in Dis Colon Rectum 2015 Nov;58(11):1021
•  American College of Radiology (ACR) Appropriateness Criteria for recurrent lower urinary tract infections in females can be found at ACR 2020 PDF

Review articles

•  review of medical treatment for rectovaginal and enterovesical fistulas in Crohn disease can be found in J Clin Gastroenterol 2016 Oct;50(9):714
• review of endoscopic management of transmural defects (leaks, perforations, and fistula) can be found in Gastroenterology 2018 May;154(7):1938

MEDLINE search

•  to search MEDLINE for (Enterovesical fistula) with targeted search (Clinical Queries), click therapy, diagnosis, or prognosis

Patient Information

•  DynaMed Editors have not identified patient education materials that meet our criteria for inclusion (freely accessible, nonpromotional, topic-specific). We will continue to search for acceptable materials and welcome your suggestions.

References

1. Golabek T, Szymanska A, Szopinski T, et al. Enterovesical fistulae: aetiology, imaging, and management. Gastroenterol Res Pract. 2013;2013:617967full-text.
2. Scozzari G, Arezzo A, Morino M. Enterovesical fistulas: diagnosis and management. Tech Coloproctol. 2010 Dec;14(4):293-300.