Editing Functional: Urinary Fistulae (section)

== Uroenteric fistula ==

=== 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

=== Ureteroenteric fistula ===

==== Causes ====
*'''Most common cause: inflammatory bowel disease (e.g. Crohn’s disease)'''
** '''Usually right-sided involving the terminal ileum'''
*** Rarely, diverticulitis or ulcerative colitis will lead to left-sided ureteroenteric fistula.
* Other causes include (6):
*#Trauma (external and iatrogenic)
*#Urothelial carcinoma
*#Radiation
*#Urolithiasis
*#Tuberculosis

==== Diagnosis and Evaluation ====
*'''History and Physical Exam'''
**'''More likely to manifest with bowel rather than urinary symptoms, unlike vesicoenteric fistulae'''
**'''Pain may also be reported in the hip, flank, or anterior thigh'''
* '''Imaging'''
**'''CT and MRI are more useful than retrograde pyelography'''

==== Management ====
*Involves ureterolysis and possible bowel resection.

=== Pyeloenteric fistulae ===

==== Causes ====
*'''Most common cause has historically been chronic inflammatory disease, such as xanthogranulomatous pyelonephritis or other infectious diseases involving the kidney or bowel.''' '''However, iatrogenic surgical trauma, especially that related to percutaneous renal surgery and percutaneous nephrolithotomy (PCNL), has been associated with an increasing number of such fistulae'''
* '''Right-sided pyeloenteric fistulae most often involve the duodenum, whereas left-sided pyeloenteric fistulae most commonly involve the descending colon'''

==== Diagnosis and Evaluation ====
*'''Majority of patients have nonspecific symptoms,''' including malaise, nonspecific GI symptoms, urinary frequency, flank mass, or tenderness.

==== Management ====
* A large nephrostomy tube, enteric suction or bowel rest, antibiotics, and removal of any foreign body (e.g., a stone) may be attempted. Internal stenting of the urinary tract may be pursued for maximal drainage.
* Fistulae associated with a poorly functioning kidney are best treated by primary closure of the bowel and nephrectomy.

=== Rectourethral fistula ===

==== Causes ====
* '''Acquired rectourethral fistula may occur in the male under a variety of clinical circumstances, including those related to prostatectomy''' for benign or malignant disease, cryotherapy, pelvic radiotherapy, anorectal surgery, external penetrating trauma, urethral instrumentation, locally advanced prostatic or rectal malignancy, infection (e.g., TB), ruptured prostatic abscess, or inflammatory disease (e.g., Crohn disease)
** '''The incidence of rectourethral fistula after radical retropubic prostatectomy is low but owing to the frequency with which the operation is performed, it is the most common cause of rectourethral fistula.'''
*** '''Rectal injury during radical prostatectomy occurs in < 1-2% of patients'''

==== Diagnosis and Evaluation ====
* '''History and Physical exam'''
**Symptoms may include fecaluria, hematuria, UTI, nausea, vomiting, and fever
* '''Imaging'''
**'''Lower tract imaging'''
***'''VCUG or retrograde urethrogram usually provides a definitive diagnosis of rectourethral fistula'''
**'''Upper tract imaging should be performed in patients to exclude a related ureteral injury'''
*'''Other'''
**'''In patients with a history of pelvic malignancy, biopsy of the fistula is suggested to evaluate for a local recurrence of the tumour''' 
***Cystoscopy and sigmoidoscopy visualize the fistula tract in the vast majority of cases and provide a mechanism for biopsy
** '''Assessment of continence and sphincteric function in patients with rectourethral fistula after radical prostatectomy'''
***Given the location of most rectourethral fistulas at or near the vesicourethral anastomosis and the membranous urethra, there is a risk for persistent severe stress incontinence postoperatively after rectourethral fistula repair

==== Management ====
* Most rectourethral fistula will require surgical repair, although some will close with conservative management.
* '''Rectourethral fistula that follows open or laparoscopic prostatectomy may heal spontaneously with catheter drainage, bowel rest, and intravenous hyperalimentation'''.
** '''In some cases, fecal diversion is necessary.'''
** '''Staged repairs might be considered in (5):'''
**# Large fistulae
**# Associated with radiation therapy
**# Uncontrolled local or systemic infection
**# Immunocompromised states
**# Inadequate bowel preparation at the time of definitive repair
* Transrectal approaches with and without division of the anal sphincter have been described for the operative repair of rectourethral fistula.
** '''The York-Mason procedure''' is a transrectal, transsphincteric approach that has been found to be effective and to have low morbidity