Vesicovaginal Fistula
HAJAR I. AYOUB
O. LENAINE WESTNEY
A vesicovaginal fistula (VVF) is an epithelialized or fibrous communication between the bladder and vagina. Physically, psychologically, and socially, it is a source of major distress for the patient contending with urine leakage from the vagina. Documentation of VVFs exists from as early as 1550 bc in the Eber papyrus of ancient Egypt (1). In 1845 James Marion Sims, considered the father of American gynecology, began his exploration into the challenges of treating the condition in Montgomery, Alabama (1). He is credited with developing the foundation of VVF repair and establishing sound surgical principles for repair of fistulas.
The causative factors leading to VVF formation can be broadly categorized into congenital and acquired (Table 24.1). The majority of cases fall into the iatrogenic and obstetrical trauma subcategories. In underdeveloped countries, the leading cause of VVFs is obstetric-related, in which prolonged labor causes ischemic pressure necrosis of the bladder and anterior vaginal wall. In contrast, obstetric trauma accounts for only 5% of VVFs in nations where modern health care is present. The leading cause of VVFs in industrialized countries is iatrogenic surgical trauma, accounting for 82% to 91% of VVFs. Ninety-one percent are due to gynecologic procedures, with 80% due to abdominal hysterectomy (2). The incidence of VVF after transabdominal hysterectomy is 1.0 in 1,000, as opposed to 0.2 in 1,000 after transvaginal hysterectomy. The incidence is highest (2.2 in 1,000) with laparoscopic hysterectomy (3). The most common location for a posthysterectomy VVF is the apex of the vaginal vault or
“cuff” corresponding to an intravesical location just superior to the trigone (2). Theoretically, the fistula develops secondary to either unintentional inclusion of full-thickness bladder wall during closure of the vaginal cuff, an unrecognized bladder injury adjacent to the cuff suture line, or cuff abscess.
“cuff” corresponding to an intravesical location just superior to the trigone (2). Theoretically, the fistula develops secondary to either unintentional inclusion of full-thickness bladder wall during closure of the vaginal cuff, an unrecognized bladder injury adjacent to the cuff suture line, or cuff abscess.
TABLE 24.1 ETIOLOGIES OF VESICOVAGINAL FISTULAS | ||
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DIAGNOSIS
Classically, the postoperative VVF presents with “continuous” urine leakage from the vagina. The time of presentation peaks at 7 to 10 days after surgery but may be variable, with some patients presenting immediately after catheter removal, ranging up to 4 to 6 weeks after surgery (3). In the early postoperative period, there may also be associated ileus and abdominal pain due to intraperitoneal urine extravasation. VVFs due to pelvic irradiation usually have a delayed presentation, developing many months or years posttreatment due to progressive obliterative endarteritis causing tissue ischemia and necrosis.
The key to diagnosis of a VVF is a high index of suspicion. Often, a complete history and physical examination expose the pathology. In the case of less obvious fistula, a dye test is utilized to more clearly visualize the passage of fluid through the fistula. In its simplest form, a saline and dye (indigo carmine or methylene blue) mixture is instilled into the bladder via a Foley catheter while inspecting the vagina for leakage or staining of a previously placed tampon. The failure to identify any discoloration of the tampon may indicate a small fistula or ureterovaginal fistula. The second level of testing requires reinsertion of a vaginal gauze or tampon followed by administration of 5 mg indigo carmine intravenously to determine whether the source is ureteral. Dye from an ureterovaginal fistula may be present on the first gauze inspection prior to intravenous (IV) indigo carmine if there is vesicoureteral reflux, which can be determined with a voiding cystourethrogram (VCUG). An alternative to IV dye injection is oral phenazopyridine hydrochloride, but it requires several hours of lead time before examination. The combination of oral phenazopyridine with intravesical methylene blue furnishes a complete diagnostic picture (4). Identification of orange discoloration on the tampon indicates a ureterovaginal fistula, whereas blue staining in the mid or lower portion of the tampon is suggestive of VVF or proximal urethrovaginal fistula.
All patients should have cystography or VCUG as an initial imaging modality. An IV pyelogram (IVP) or retrograde ureterograms is essential for upper tract evaluation. However, CT urography and/or magnetic resonance imaging have been proven to be helpful in cases where conventional imaging modalities fail (4). Abnormalities to look for include extravasation into the vagina or peritoneal cavity or a displaced or partially obstructed ureter. In patients with VVF, up to 25% will have hydroureteronephrosis, with 10% having a concomitant ureterovaginal fistula (5). In patients with ureteral pathology, a retrograde pyelogram is warranted to evaluate for ureterovaginal fistula if the IVP is not definitive.
Cystoscopy is performed to localize and evaluate the VVF, which often has surrounding edematous mucosa. The size and number of VVFs, their location in relation to the ureteral orifices, any lesions such as foreign bodies (i.e., sutures), tumors, and tissue quality must be noted. If there is a history of malignancy, biopsy of the VVF is indicated to rule out recurrent tumor. Vaginoscopy is performed simultaneous with cystoscopy to assess the vaginal aspect of the fistula. If IVP and retrograde pyelograms are inconclusive, then a fistulogram may be performed transvaginally.
A urodynamic study is recommended to look for other factors that may contribute to the urinary incontinence and may require surgical correction (augmentation cystoplasty, incontinence surgery) with the VVF repair simultaneously. Bladder compliance, capacity, and leak point pressure should be assessed if possible. In cases of a large fistula, a Foley catheter may be used to intubate and occlude the fistulous tract to allow for filling of the bladder.
INDICATIONS FOR SURGERY
The issue of how long to wait before attempting surgical repair of a VVF has long been debated. By tradition, VVF repair is delayed 3 to 6 months to allow inflammation to resolve. In cases where a VVF is due to a complicated operation or after obstetric trauma, this rationale holds true. Moreover, reported success rates in obstetric-induced fistula are less than those posthysterectomy as one would expect based on the mechanism—ischemia. These success rates have ranged widely from 53.6% (6) to 97.5% (7,8), with an average closure rate of 86%. Bukar et al. (9) compared a total of 80 women with obstetric-related VVF with an average size of 5 cm, of which 51% presented early for VVF repair (<12 weeks) and 49% presented late (>12 weeks). Irrespective of early or late repair, no difference was reported regarding closure success rate; however, in the early closure group, the psychological, social, and financial burdens were significantly reduced (9). Furthermore, independent studies by Blaivas et al. (10) and Blandy et al. (11) demonstrated comparable results with early (6 to 12 weeks) repair in cases related to an uncomplicated hysterectomy.
Once surgical repair is planned, the approach needs to be selected—transvaginal, transvesical, or transabdominal. Often, the preference correlates significantly with the experience of the surgeon. Advantages of the transvaginal approach are less blood loss, shorter hospital stay, avoidance of a laparotomy, and thus decreased morbidity. Many reserve the transabdominal approach for those patients requiring concomitant intra-abdominal surgery (ureteral reimplantation, augmentation cystoplasty) or those patients with a narrow and deep vagina causing poor exposure to the VVF. However, Dupont and Raz (12) reported that nearly all VVFs can be accessed and repaired transvaginally.
NONSURGICAL THERAPY—CONSERVATIVE AND ENDOSCOPIC
Upon diagnosis, a trial of conservative therapy may be initiated depending on fistula size. Conservative management consists of prolonged bladder drainage with a Foley catheter, anticholinergic agents to prevent bladder spasms, antibiotics, and estrogen if the patient is postmenopausal. Successful closure of a VVF via conservative means can only be reasonably expected for small fistula—3 to 5 mm in diameter or less.
Other adjunctive minimally invasive treatments include attempts to destroy the epithelial lining of the VVF with fulguration (using electrocautery or laser) and use of occlusive
substances. Dogra and Saini (13) reported on a group of eight fistula patients (five failed prior conservative therapy and three failed primary repair) in which holmium:YAG laser was successfully used for circumferential welding of the fistula (2 to 4 mm) in seven of eight patients. In the remaining patient, the procedure was abandoned for bleeding; however, the majority was dry at mean follow-up of 47 months (13).
substances. Dogra and Saini (13) reported on a group of eight fistula patients (five failed prior conservative therapy and three failed primary repair) in which holmium:YAG laser was successfully used for circumferential welding of the fistula (2 to 4 mm) in seven of eight patients. In the remaining patient, the procedure was abandoned for bleeding; however, the majority was dry at mean follow-up of 47 months (13).
Since the late 1980s, adhesive materials have been used to treat a variety of fistulas. There are two main types of glues used to treat VVF: fibrin, a biologic product, and synthetic cyanoacrylic glue. The experience with fibrin glue has longer reported follow-up.
A few small series have discussed on the use of fibrin glue to treat VVF demonstrating a good success rate (14,15). Schneider et al. (14) reported six cases using endoscopic techniques and found a 66% closure rate using glue compared with 88% success with a traditional repair. Although it may involve more than one injection to treat the fistula, fibrin glue promotes healing, is biodegradable, and has been used successfully in a large variety of urologic fistulas, including those caused by irradiation (14). Ghoreifi et al. (16) recently described a 100% success rate in 12 patients using autologous platelet-rich plasma injection and platelet-rich fibrin glue interposition (16).
Synthetic cyanoacrylic glue is a relatively newer product in occlusion therapy of fistulas. It polymerizes in 90 seconds once injected and can be used without difficulty in a wet environment such as the genitourinary tract; this, together with its antimicrobial properties, makes it an attractive option for the treatment of VVF. The best results are achieved in fistulas characterized by a long tract and diameter <1 cm. Application can be performed from either transvaginal or cystoscopic approaches with Foley catheter removal between 48 hours and 3 weeks depending on the size of the fistula. Generally, followup cystography is performed in 1 to 3 months.
The benefits of using occlusion therapy to treat VVFs include the ability to treat the fistula earlier rather than expecting the patient to endure the distressing symptoms of the fistula for up to 3 months while awaiting definitive surgery. Additionally, there is very low morbidity associated with occlusion therapy. There have been no reported complications from occlusion therapy treatment of VVF, other than the occasional necessity of removing excess glue endoscopically. Importantly, it does not preclude other forms of treatment if it is unsuccessful. Although occlusion therapy appears to be safe and efficacious in selected, small VVFs, more longer term and randomized studies are needed to evaluate its durability.
SURGICAL TECHNIQUES
Transvaginal Approach
Transvaginal VVF repair is the least invasive surgical approach because the vagina in its native state serves as a natural orifice facilitating performance on an outpatient (<24 hour admission) basis. The patient is placed in the dorsolithotomy position. If a narrow vagina is present or the VVF site is high lying, a Schuchardt posterolateral relaxing incision at the 4 o’clock position of the vaginal introitus and distal vaginal wall may be performed to improve exposure. A suprapubic catheter is positioned with a Lowsley retractor, and a urethral Foley catheter is placed. The labia minora are sutured to the inner thigh and a weighted vaginal speculum placed. The VVF is dilated to place an 8Fr Foley catheter. Applying gentle traction to the catheter aids in exposure and dissection of the VVF.
 FIGURE 24.1 The apex of the vaginal inverted U incision is continuous with the circumferential fistula incision. (Modified with permission from Raz S, Bregg KJ, Nitti VW, et al. Transvaginal repair of vesicovaginal fistula using a peritoneal flap. J Urol 1993;150:56-59. Copyright © 1993 American Urological Association, Inc. Published by Elsevier Inc. All rights reserved.) |
After submucosal injection of a vasopressin mixture (10 U per 100 mL normal saline), lidocaine with 1% epinephrine, or saline to elevate the anterior vaginal mucosa, the VVF is circumferentially incised. A posteriorly based inverted Ushaped incision is made with the apex continuous with the VVF incision (Fig. 24.1). If the VVF is situated deep in the vaginal vault, an anteriorly based U-shaped incision is utilized. The vaginal mucosa is dissected away from the perivesical fascia to form vaginal flaps anterior and posterior to the VVF (Fig. 24.2). Unless nonviable, the fistulous tract is not excised as excision enlarges the defect and risks injury to the intramural ureter. Left intact, the fistula tract also provides strength to the VVF closure, helping decrease the risk of VVF repair disruption due to bladder spasms.
The fistula is closed in two nonoverlapping, perpendicular layers to prevent fistula recurrence. The first layer closes the fistula with interrupted 4-0 polyglycolic acid sutures, incorporating the vaginal wall overlying the VVF, the fistula tract, and the partial thickness of the bladder wall (Fig. 24.3). The second layer, using 2-0 polyglycolic acid sutures, imbricates the perivesical fascia and the deeper musculature of the bladder over the first layer in a tension-free fashion. The repair is checked for leaks by instilling indigo carmine into the bladder. The vaginal wall is advanced over the VVF repair and closed with an interlocking, running 2-0 polyglycolic acid suture. A Betadine-soaked vaginal pack is placed.
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