Editing Functional: Urinary Fistulae (section)

=== Vesicoenteric fistula ===

==== Causes ====
# '''<span style="color:#ff0000">Diverticulitis (most common cause of colovesical fistulae)</span>'''
# '''<span style="color:#ff0000">Malignancy (e.g. colon cancer)</span>'''
# '''<span style="color:#ff0000">Crohn disease</span>'''
* Less common causes include radiation, infection, and trauma—external penetrating trauma, as well as iatrogenic surgical trauma

==== Diagnosis and Evaluation ====

* '''History and physical exam'''
** '''<span style="color:#ff0000">Pneumaturia is the most common presenting symptom'''
**'''<span style="color:#ff0000">Classic presentation of vesicoenteric fistula''' (described as Gouverneur syndrome) '''<span style="color:#ff0000">consists of (4):'''
**#'''<span style="color:#ff0000">Suprapubic pain'''
**#'''<span style="color:#ff0000">Urinary frequency'''
**#'''<span style="color:#ff0000">Dysuria'''
**#'''<span style="color:#ff0000">Tenesmus''' 
**Symptoms of vesicoenteric fistulae may originate from the urinary or GI tract; however, in general, '''<span style="color:#ff0000">storage LUTS are more common at presentation.''' 
** '''<span style="color:#ff0000">Recurrent UTIs or cystitis refractory to antibiotic therapy may suggest a colovesical fistula'''

* '''Imaging'''
** '''Cross-sectional imaging'''
*** Modality of choice
*** '''<span style="color:#ff0000">CT with contrast</span>'''
****'''<span style="color:#ff0000">Generally considered to be the most sensitive and specific modality for the diagnosis of colovesical fistulae</span>'''
**** '''<span style="color:#ff0000">Findings on CT that are suspicious for colovesical fistulae (3):</span>'''
****# '''<span style="color:#ff0000">Bladder wall thickening adjacent to a loop of thickened colon</span>'''
****# '''<span style="color:#ff0000">Air in the bladder (in the absence of previous lower urinary manipulation)</span>'''
****# '''<span style="color:#ff0000">The presence of colonic diverticula</span>'''
[[File:CT colovesical fistila.jpg|alt=Bladder wall thickening adjacent to a loop of thickened bowel|505x505px|CT scan with IV and oral contrast, coronal view, demonstrating bladder wall thickening adjacent to a loop of thickened bowel. 57M with history of diverticulitis, dysuria, urinary frequency, and fecaluria.|thumb|none]]

** '''Cystography and transrectal contrast studies (e.g., barium enema)'''
***'''Although commonly used are less likely to demonstrate the fistula'''

* '''Other'''
** '''<span style="color:#ff0000">Endoscopy</span>'''
*** '''<span style="color:#ff0000">The finding of bullous edema during cystoscopy is nonspecific; however, in the appropriate clinical setting, this can be very suggestive of a colovesical fistula.</span>'''
**** '''80-100% of cases of colovesical fistulae have an abnormality noted on cystoscopy'''
** Bourne test
*** Performed after a nondiagnostic barium enema.
*** The first voided urine after the barium enema is immediately centrifuged and then examined radiographically. Radiodense particles in the urine are considered a positive test result and evidence for a vesicoenteric fistula
** Activated charcoal
*** Oral administration of activated charcoal, which, in the setting of a fistula, will appear in the urine as black particles

==== Management ====
* '''<span style="color:#ff0000">Nonoperative management</span>'''
** '''<span style="color:#ff0000">Option in selected nontoxic, minimally symptomatic patients with nonmalignant causes with vesicoenteric fistula</span>'''
** <span style="color:#ff0000">'''Trial of medical therapy including intravenous total parenteral nutrition, bowel rest, and antibiotics'''</span> may be warranted. 
***'''May be the preferred initial approach,''' especially in patients with '''Crohn disease, in whom the notion of immediate exploratory laparotomy and bowel resection is often discouraged because of the chronic relapsing nature of the disease'''
* '''<span style="color:#ff0000">Operative management</span>'''
** <span style="color:#ff0000">'''Goal is to separate and close the involved organs with minimal anatomic disruption and normal long-term function of both systems.'''</span>
** '''Both single and multistage procedures have been advocated,''' depending on the clinical circumstances.
*** A one-stage procedure involves removal of the fistula, closure of the involved organs, and primary reanastomosis of the bowel after resection of the involved bowel segment.
*** A two-stage approach advocates removal of the fistula, closure of the involved organs, and creation of a temporary proximal diverting colostomy, with a later return to the operating room for colostomy takedown once the fistula tract has been demonstrated to be closed