Urogenital Fistula – Causes, Symptoms, Treatment

Diagnosis of Urogenital Fistula

• The physical examination – begins with collecting vital signs and performing a neurologic and gait evaluation [rx]. A visual inspection should always be the first step in the genital exam with evaluation for perineal dermatitis, ulceration, infection, and scarring from a prior episiotomy, circumcision, or fistula repair [rx].
• Abdominal and bimanual examination –  noting the severity and nature of vaginal and rectal scarring; location, size, and a number of fistulae; and involvement of crucial structures such as the urethral sphincter, anal sphincter, and urethra itself [rx].
• Vaginal speculum exam  – for improved exposure, or a test [rx]. The tests generally involve back-filling the bladder and temporarily occluding the urethra for evaluation of dye leakage. If the fistula cannot be immediately located, some authors recommend vaginal packing, with the location of dye leakage on the pack used to help narrow down the fistula position [rx]. Additionally, oral Pyridium or intravenous indigo carmine can be administered to assess ureteral involvement [rx, rx].
• Hemoglobin determination and testing – for sexually transmitted infections are also recommended, as the former is important for pre-operative planning, and the latter because sexually transmitted infections can be the cause of a fistula (and their treatment may allow for spontaneous fistula closure), and they can also cause friability of the tissue which will complicate fistula closure. Additionally, patients who are HIV positive may require treatment and rehabilitation prior to surgery to improve their surgical outcomes.
• Tampon dye test – This test involves inserting a regular tampon or gauze in the vagina, then back-filling the bladder with dilute methylene blue and having the patient ambulate – this can be performed shortly after filling the bladder, and a prolonged period of ambulation is not required as long as the bladder was sufficiently full with 200-300 mL of fluid. It is preferable to place the gauze or tampon prior to back-filling the bladder to avoid contaminating the gauze with dye during insertion. The tampon or gauze is then removed and inspected; if there is blue dye noted on the gauze near the apex, a vesicovaginal fistula is confirmed. If the dye is only noted on the distal tampon, this may represent spillage of the dye during filling or other forms of urinary incontinence.[rx][rx]
• Office cystoscopy – and contrast studies, such as computed tomography (CT) urogram, are generally used to aid in the diagnosis of additional injuries (such as a concomitant urethral injury or fistula) and for surgical planning.

Treatment of Urogenital Fistula

The primary goal of fistula treatment is continence. Obtaining continence generally requires surgery, but maybe achieved by conservative treatment with catheters or stents, or require a more aggressive diversionary procedure [rx, rx].

Conservative management

Women with a small simple fistula discovered shortly after delivery, or those presenting to a facility with obstructed labor, may be treated conservatively with the insertion of a Foley catheter for somewhere between two and six weeks, twice daily sitz baths, high volume oral intake of fluids, and treatment of any obvious concurrent infections [rx]. Currently available data are of poor quality and no clear recommendations can be made as to whether initial conservative management with a Foley catheter is appropriate or effective [rx]. However, since 1942, papers have been published suggesting use of a Foley catheter as a method of assisting spontaneous closure of vesicovaginal fistulae less than one centimeter in size [rx]. Similarly, ureteral stents placed for one to two months may result in spontaneous resolution of fistulas involving the ureter in greater than half of the cases [rx, rx]. Ureteral stents are usually placed, in this context, by way of cystoscopy, which may not be available in LIC.

Surgical management

For most patients, surgery is the only option. The overriding principle of fistula repair is that the first attempt offers the best chance of successful closure [rx]. The basic principles of surgical repair are: 1) achieving adequate exposure, 2) mobilizing the fistula from surrounding scar tissue, so that 3) a tension-free closure can be performed that is water-tight [rx, rx].

Timing of surgery

While the traditional teaching is that patients undergo surgery three months after diagnosis to allow time for the fistulae to become less inflamed, more recent data suggest that fistulae be repaired immediately if diagnosed within 72 h of delivery, or even within the three-month window, as repair within this timeframe prevents a significant amount of the negative social, economic, and physical sequelae associated with incontinence [rx, rx, rx, rx]. Some patients, however, may present years after fistula formation. For these patients, if there is no residual edema, erythema, or persistent granulation tissue, and no need for treatment of infections, anemia, or malnutrition, surgery can be pursued without additional delay [rx]. Iatrogenic fistulae should undergo surgical repair with diagnosis unless the fistula is the result of the retained suture. In that case, waiting until the suture is resorbed is in order [rx, rx].

Pre-operative care

The WHO advises pre-operative management include anesthesia evaluation, skin preparation, hair clipping, high oral fluid intake, bowel preparation, and nothing by mouth from midnight of the night before surgery [rx]. Issues such as nutritional supplementation and pre-operative estrogen usage, as well as transfusion or supplementation for anemia and empiric treatment with antimalarials, antibiotics, or antiparasitics, are topics for further research.

Surgical methods

The WHO guidelines recommend a vaginal approach to urogenital fistula repair. The optimal surgical position is high lithotomy, and the optimal anesthetic technique is regional [rx]. Vaginal repair is associated with less blood loss, results in shorter operative time leads to decreased use of analgesics, and overall accounts for shorter hospital length of stays [rx]. Various antibiotic regimens, which include single-dose gentamicin, appear to be equally effective at decreasing post-operative urinary tract infections and improving leakage and incontinence profiles on discharge from the hospital [rx, rx]. Commonly performed initial surgical steps include episiotomy for exposure, placement of retractors that assist with visualization, Foley catheterization to divert urine from the operative field, protection of the ureters with stents, and placement of a probe into the fistula to delineate its course and establish its boundaries [rx].

Closure methods include the Latzko technique (partial colpocleisis without excision of the fistula tract), layered closure (excision of the fistulous tract), and use of flaps, which may be biologic (such as the Martius flap—a labial fat pad), but also include more recent experimentation with synthetic materials [rx, rx, rx]. Studies have shown the Latzko technique to be quite effective with success rates quoted as 93 to 100 %, and placement of the Martius flap to have 70 – 100 % success rates, with the caveat that the latter method is used in the setting of more complicated fistulae with greater fibrosis and necrosis, or lack of tissue available for closure [rx]. There is also a role for more invasive procedures that necessitate an abdominal approach for patients with reduced bladder capacity or pliability, involvement of the ureter, trigone, ureteral orifice, or cervix, and inability to access the fistula by way of the vagina, or for patients who have not achieved continence after multiple repairs or those whose fistula is too large, or the remaining tissue is too scarce, that anatomic closure is not possible [rx, rx].

Minimally invasive surgery

Although minimally invasive surgery (MIS) such as laparoscopy and robotics is more accessible in high-income countries (HIC), a group in India is utilizing MIS to repair urogenital fistulae resulting from obstetric complications [rx]. This group reportedly closed vesicovaginal fistulae with a single layer continuous laparoscopic suture with interposition of an omental flap; urethral catheters were left in situ for a month post-operatively [rx]. As the capacity for MIS in LIC builds, it will be interesting to see how this experience contributes to the surgical literature.