Editing Functional: Urinary Fistulae (section)

=== Ureterovaginal fistula ===

==== Causes ====
* '''<span style="color:#ff0000">Surgical injury to the distal 1/3 ureter (below the level of the iliac vessels)</span>'''
** '''<span style="color:#ff0000">Most common cause: hysterectomy</span>''' for benign indications
*** Most common injury to the urinary tract during hysterectomy is a bladder laceration. 
****Although ureteral injuries are not uncommon, they occur far less frequently than bladder injuries.
** The pelvic ureter is intimately related to the female genital tract throughout its course.
*** In the deep pelvis, the ureter passes at the lateral edge of the uterosacral ligament and ventral to the uterine artery, and then passes just lateral to the cervix and fornix of the vagina.
** In females who undergo vaginal surgery (such as hysterectomy) or sustain penetrating pelvic trauma involving the vagina, an initially unrecognized ureteral injury can present in a delayed manner with ureterovaginal fistula.
* '''Other risk factors include: gynecologic surgery (cesarean section, anterior colporrhaphy (cystocele repair)), vascular surgery, urologic surgery including retropubic bladder neck suspensions, colon surgery, locally advanced malignancy, radiation therapy, pelvic trauma, chronic inflammatory diseases (e.g., actinomycosis), endometriosis and obesity'''
** Incidence of iatrogenic ureteral injury during major gynecologic surgery ≈0.5-2.5%

==== Diagnosis and Evaluation ====

* '''History and Physical Exam'''
** '''<span style="color:#ff0000">Most common presenting symptom is the onset of constant urinary incontinence 1-4 weeks after surgery.</span>'''
** '''<span style="color:#ff0000">In direct contrast to VVF, in the setting of continuous urine leakage from a ureterovaginal fistula, patients will continue to report normal voiding habits because bladder filling is maintained from the contralateral, presumably undamaged, upper urinary tract</span>'''

* '''Imaging'''
** '''<span style="color:#ff0000">Suspicion of a ureterovaginal fistula should prompt upper tract imaging</span>'''
*** Ureterovaginal fistulae may be seen on CT urography or MRI.
*** '''CT urogram most commonly will demonstrate some degree of ureteral obstruction and associated caliectasis or ureteral dilation. These findings in the presence of constant vaginal drainage strongly suggest a ureterovaginal fistula.'''
**** Alternatively, if the fistula is mature and large, the upper urinary tract may appear completely unremarkable; however, urine will be seen opacifying the vagina before the postvoid image.
*** If '''retrograde pyelography''' demonstrates the fistula, as well as ureteral continuity, then an attempt at stenting is warranted.
*** '''Cystography is performed primarily to exclude a coexistent VVF.'''
**** A cystogram will not demonstrate the ureterovaginal fistula unless there is preexisting vesicoureteral reflux.

==== Management ====
* Goals of treatments are:
** Resolving urinary leakage
** Avoiding urosepsis
** Preserving of renal function
* '''<span style="color:#ff0000">Once the diagnosis is made, prompt drainage of the affected upper urinary tract is essential</span>''' '''because partial ureteral obstruction is often present.'''
** '''An attempt at ureteral stenting or percutaneous nephrostomy tube decompression is warranted as soon as possible if direct open surgical repair is not immediately considered.'''
** '''Ureteral stenting may be sufficient to promote closure of the fistula in some cases'''
*** In some cases, an antegrade stent placement will be successful where a retrograde attempt had failed.
* '''<span style="color:#ff0000">If ureteral stenting is unsuccessful owing to complete ureteral occlusion or if prolonged leakage persists despite stenting, then formal surgical repair is indicated</span>'''
** Timing of the repair of ureterovaginal fistulae is controversial.
** '''Open surgical repair most commonly involves ureteroneocystostomy since most injuries occur to the distal ureter'''
** Repair is successful in >90% of cases