Occasionally, genitourinary fistulas may spontaneously close during continuous bladder drainage using an indwelling urinary catheter. Approximately 12 percent of women treated by sustained catheterization alone had fistulas that healed spontaneously (Oakley, 2014; Waaldijk, 1994). Romics and colleagues (2002) found that in 10 percent of cases, urinary fistulas close spontaneously after 2 to 8 weeks of transurethral catheterization, especially if the fistula is small (2- to 3-mm diameter). Another series reported fistulas up to 2 cm in diameter spontaneously healed in 50 to 60 percent of patients treated with an indwelling catheter (Waaldijk, 1989).
Despite these series, data that correlate fistula size and success of conservative management are limited. Many reports of successful spontaneous closure with catheter drainage have been limited to fistulas that were 1 cm in size or smaller (Lentz, 2005; Ou, 2004). Many studies are vague regarding how fistula size is measured, and each series has potential for considerable bias in its selection criteria. However, in general, the larger a fistula, the less likely it is to heal without surgery.
Evidence regarding the duration of catheter drainage also varies. Regardless, many agree that if a fistula has not closed within 4 weeks, it is unlikely to do so. This may be secondary to epithelialization of the fistulous tract (Davits, 1991; Tancer, 1992). Moreover, continued urinary drainage may lead to further bladder inflammation and irritation (Zimmern, 1991). Importantly, if attempting conservative treatment of a vesicovaginal fistula with catheter insertion and chronic drainage, urinary drainage ideally begins shortly after the inciting event.
Fibrin sealant (Tisseal, Evicel), also colloquially called fibrin glue, is formed from concentrated fibrinogen combined with thrombin to simulate the final clotting cascade stages. In gynecologic surgery, it is mainly used to control low-pressure bleeding. Although fibrin sealant has been described for the treatment of vesicovaginal fistula, it is often selected as a surgical adjunct rather than primary surgical treatment (Evans, 2003). Data regarding fibrin sealant effectiveness are sparse, and well-designed trials are lacking. Thus, fibrin sealant monotherapy may not be the initial recommended treatment in most vesicovaginal fistula cases due to potential lack of durability and thus a risk for recurrence. However, it may provide a viable alternative in patients with multiple comorbidities that contraindicate a prolonged fistula repair surgery.
In sum, a trial of conservative therapy is usually warranted and reasonable, especially if instituted shortly after the inciting event and if the fistula is small. However, gains from a conservative approach are balanced against a patient’s desire for an expedited repair to resolve the leak. Thus, the timing of intervention ideally achieves a compromise between reasonable conservative efforts and addressing the patient’s immediate distress and quality of life. As noted, most urinary fistulas ultimately require surgical intervention.
Incorporating the fundamentals of genitourinary fistula repair is essential to successful resolution. These include accurate fistula delineation; adequate assessment of surrounding tissue vascularity; timely repair; multilayer, tension-free, and watertight defect closure; and postoperative bladder drainage.
Primary surgical repair of genitourinary fistula is associated with high cure rates (75 to 100 percent) (Rovner, 2012b). Factors that support this rate include adequate vascularity of the surrounding tissue, brief fistulous tract duration, no prior radiation therapy, meticulous surgical technique, and surgeon experience. The first attempt at surgical repair is usually associated with the best chance of successful healing. Surgical repair success rates specifically for obstetric fistulas are also high. Of these, 81 percent are corrected with the first attempt, and 65 percent with the second (Elkins, 1994; Hilton, 1998).
One principle of fistula repair dictates that a repair be performed in noninfected and noninflamed tissues. Early surgical intervention of uncomplicated fistulas within the first 24 to 48 hours following the inciting surgery is possible as it avoids the brisk postoperative inflammatory response. Such early closure does not affect success rates, yet it appears to reduce social and psychologic patient distress (Blaivas, 1995; Persky, 1979).
In instances of extensive and severe inflammation, we recommend delaying operative repair for 6 weeks until the inflammation subsides. During this time, a trial of catheter drainage, while the surrounding tissue has an opportunity to heal, is reasonable.
Many different surgical repair options are available for vesicovaginal fistula. However, data that support an optimal route are limited, and the lack of consensus may reflect variances in surgeon experience and preference. Among important surgical considerations, ability to gain access to the fistula is essential and commonly dictates the surgical approach. Fortunately, success rates are high whether the route of repair is transvaginal or transabdominal.
The transvaginal approach to genitourinary fistula repair is straightforward and direct. Compared with abdominal approaches, it is associated with shorter operative times, decreased blood loss, less morbidity, and shorter hospital stays (Wang, 1990). The transvaginal route also allows easy access for the use of ancillary equipment, such as ureteral stents. This is particularly useful if the fistula is located near ureteral orifices.
One transvaginal approach used most commonly by gynecologists, the Latzko technique, is illustrated in Section 45-10. In this technique, likened to a partial colpocleisis, the most proximal portions of the anterior and posterior vaginal walls are surgically apposed to close the defect, without completely removing the fistulous tract. This partially obliterates the upper vagina, similar to that achieved by colpocleisis. Because of the potential for vaginal shortening, this technique may not be appropriate if vaginal depth has already been compromised or if there is preexisting sexual dysfunction. If use of the Latzko technique is anticipated, patient counseling specifically addresses these issues and potential sequelae. That said, recent studies evaluating sexual function show similar or higher functioning scores following vaginal repair routes compared with abdominal routes (Lee, 2014; Mohr, 2014).
The classical technique, in contrast to the Latzko method, involves total excision of the fistulous tract and mobilization of the surrounding anterior vaginal wall epithelium. After tract resection, the bladder mucosa is first closed, and a watertight repair is confirmed. This is followed by closure of one or two layers of fibromuscular tissue. Vaginal epithelium is then reapproximated.
Of the two approaches, some favor incomplete fistulous tract excision (Latzko repair) to avoid weakening the surrounding tissue, enlarging the defect, and thereby potentially compromising the repair. By preserving the presumptively stronger scar tissue surrounding the fistula, it theoretically permits a more secure reapproximation of surrounding tissue.
With this route, the fistula is accessed and excised through an intentional cystotomy on the preperitoneal side of the bladder as shown in Section 45-10. This approach is used for situations in which the fistula: (1) is located proximally in a narrow vagina, (2) lies close to the ureteral orifices, (3) is complicated by a concomitant ureteric fistula, (4) persists after prior repair attempts, (5) is large or complex in configuration, or (6) requires an abdominal interposition graft, described in the next section.
Evidence-based support for laparoscopic genitourinary fistula repair has been limited to case reports and expert opinion (Miklos, 2015; Nezhat, 1994). The technique requires advanced laparoscopic surgical skills. Accordingly, success with this approach appears to be highly dependent on surgeon experience.
Surrounding tissue vascularity is essential for successful genitourinary fistula healing after repair. When intervening tissues for fistula closure are thin and poorly vascularized, various tissue flaps may be placed vaginally or abdominally between the bladder and the vagina in an attempt to enhance the repair and to lend support and blood supply (Eisen, 1974; Martius, 1928). Sections 45-10 and 45-11 illustrate the omental J-flap, which is an abdominal option, whereas the Martius bulbocavernosus fat pad flap is used during vaginal procedures. Although interposition flaps are useful in situations where tissue viability is in question, their utility in uncomplicated cases of vesicovaginal fistula is unclear.
Other Genitourinary Fistulas
Although vesicovaginal fistulas are the most common type of genitourinary fistula, other fistulas can develop and may be described based on their communication between anatomic structures. Urethrovaginal fistulas can result from surgery involving the anterior vaginal wall, in particular anterior colporrhaphy and urethral diverticulectomy (Blaivas, 1989; Ganabathi, 1994a). In developing countries, as with vesicovaginal fistula, obstetric trauma remains the most common cause of urethrovaginal fistulas. Frequently, patients present with continuous urinary drainage into the vagina or with stress urinary incontinence. The principles of repair are similar, namely, layered closure, tension-free repair, and postoperative bladder drainage. Other types of genitourinary fistula can also develop (see Table 26-1).