Vesicovaginal Fistula Workup

Updated: Nov 11, 2021
  • Author: John Spurlock, MD; Chief Editor: Christine Isaacs, MD  more...
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Laboratory Studies

Upon examination of the vaginal vault, any fluid collection noted can be tested for urea, creatinine, or potassium concentration to determine the likelihood of a diagnosis of VVF as opposed to a possible diagnosis of vaginitis.

Indigo carmine dye can be given intravenously and if the dye appears in the vagina, a fistula is confirmed.

Once the diagnosis of urine discharge is made, the physician must identify its source. Cystourethroscopy may be performed, and the fistula(s) may be identified. If ureter involvement is suspected then IVP can be performed.

The differential diagnosis for the discharge of urine into the vagina includes single or multiple vesicovaginal, urethrovaginal, or ureterovaginal fistulas and fistula formation between the urinary tract and the cervix, uterus, vagina, vaginal cuff, or (rarely) ureteral fistula to a fallopian tube.

A full vaginal inspection is essential and should include assessment of tissue mobility; accessibility of the fistula to vaginal repair; determination of the degree of tissue inflammation, edema, and infection; and possible association of a rectovaginal fistula.

Urine should be collected for culture and sensitivity, and patients with positive results should be treated prior to surgery.

In patients with a history of local malignancy, a biopsy of the fistula tract and microscopic evaluation of the urine is warranted.


Imaging Studies

Radiologic studies should be employed prior to surgical repair of a VVF. An intravenous urogram (IVU) is necessary to exclude ureteral injury or fistula because 10% of VVFs have associated ureteral fistulas. If suspicion is high for a ureteral injury or fistula and the IVU findings are negative, retrograde ureteropyelography should be performed at the time of cystoscopy and examination under anesthesia. A Tratner catheter can be used to assist in evaluation of a urethrovaginal fistula.

Fibrin occlusion therapy is used for the treatment of a variety of fistulas, such as enterocutaneous, anorectal, bronchopleural, ureterocutaneous, and, more recently, VVFs. Fistulograms are a valuable adjunct to fibrin occlusion therapy.


Diagnostic Procedures

Intraoperative assessment for bladder or ureteral injury may be performed by administering indigo carmine intravenously and closely observing for any subsequent extravasation of dye into the pelvis. Cystourethroscopy to assure bilateral ureteral patency and absence of suture placement in the bladder or urethra has been advocated by some authors as a standard for all pelvic surgery.

Alternatively, intraoperative back-filling of the bladder with methylene blue or sterile milk before completing abdominal or vaginal surgery also may help detect a bladder laceration. Retrograde filling of the bladder also can be used during surgery to better define the bladder base in more difficult dissections.

In the office, the evaluation should include a complete physical examination and detailed review of systems. A cystoscopic examination with a small scope (eg, 19F) may be used to identify VVF in the bladder or urethra, to determine the number and location and proximity to ureteric orifices, and to identify and remove abnormal entities such as calculi or sutures in the bladder.

In the office, as with the operating room setting, the bladder can be filled with sterile milk or methylene blue in retrograde fashion using a small transurethral catheter. Placement of tampons in tandem in the vaginal vault and observation for staining of the tampons by methylene blue may help to identify and locate fistulas.

Staining of the apical tampon would implicate the vaginal apex or cervix/uterus/fallopian tube; staining of a distal tampon raises suspicion of a urethral fistula. If the tampons are wet but not stained, oral phenazopyridine (Pyridium) or intravenous indigo carmine then can be used to rule out a ureterovaginal, ureterouterine, or ureterocervical fistula. Evidence of staining or wetting of a tampon should then prompt the physician to proceed with additional diagnostic testing prior to proceeding with definitive management.

Water cystoscopy may be inadequate in the face of large or multiple fistulas.

A cystoscopic examination using carbon dioxide gas may be used with the patient in the genupectoral position. With the vagina filled with water or isotonic sodium chloride solution, the infusion of gas through the urethra with a cystoscope produces air bubbles in the vaginal fluid at the site(s) of a UGF (flat tire sign).

Combined vaginoscopy-cystoscopy may be useful. Andreoni et al describe their technique of simultaneously viewing 2 images on the monitor screen (both cystoscopic and vaginal examinations). [16] They use a laparoscope and clear speculum in the vagina and they use regular cystoscope in the bladder to enhance visualization and identification of VVFs. Transillumination of the bladder or vagina by turning off the vaginal or bladder light source allows for easier identification of the fistula in the more difficult cases.

Color Doppler ultrasonography with contrast media of the urinary bladder may be considered in cases where cystoscopic evaluation is suboptimal, such as in those patients with severe bladder wall changes like bullous edema or diverticula. Color Doppler ultrasonography demonstrated a VVF in 92% of the patients studied by Volkmer and colleagues using diluted contrast media and observing jet phenomenon through the bladder wall toward the vagina. [17]